Student Research

Student research projects carried out as either capstone projects in the master’s program or as doctoral dissertations are listed here. For the capstone projects, the student, year and project title are shown. For the doctoral dissertations, abstracts are also included.

Research is divided by concentration:
Pollution Prevention/Cleaner Production
Epidemiology
Ergonomics/Safety
Occupational and Environmental Hygiene
Work Environment Policy

Pollution Prevention/Cleaner Production

Armenti, Karla: ScD (2001)
Title: Primary prevention for occupational health: using the pollution prevention model to promote the integration of occupational and environmental health

Veleva, Vesela R.: ScD (2001)
Title: Developing indicators of sustainable production
Abstract: This dissertation proposes a new tool for operationalizing the concept of sustainable development at the level of the individual firm - indicators of sustainable production. Such indicators help raise awareness, inform decision-making and promote continuous improvement.

The dissertation is comprised of four manuscripts.

The first manuscript discusses the business case for sustainable development and introduces sustainable production as a way to equally address different aspects of production (environmental and occupational, social and economic). Indicators are suggested as a tool for operationalizing this concept and their objectives, scope and desirable qualities are outlined. The second manuscript analyzes existing sustainability indicator frameworks for business to identify strengths and weaknesses in the current practice. Four indicator frameworks are evaluated in a greater detail. The paper concludes with a summary and recommendations for developing a new framework and methodology for indicators of sustainable production.

The third manuscript is the core of the dissertation. Building on existing indicator work and the Lowell Center for Sustainable Production framework, a new methodology of core and supplemental indicators of sustainable production is suggested. Twenty-two core indicators are proposed and a detailed guidance for their implementation is included.

The fourth manuscript presents the results of testing the methodology at three companies in New England. It concludes with a summary of the key lessons learned and recommendations for future work.

The main benefit of the dissertation is the development of a set of integrated indicators of sustainable production and a methodology for companies to use these and create additional production-specific indicators. Such indicators link environmental, social and economic aspects of industrial activities and allow companies to benchmark their achievements. They promote the learning experience for companies, since the implementation is done through the organizational learning process. The developed sample set of indicators may eventually become the basis of standardized sustainability indicators for companies.

Choi, Myung H.: ScD (1999)
Title: Quantitative evaluation method for the promotion of cleaner production using non-chlorinated cleaning alternatives in electroplating job shops
Abstract: This study is to promote cleaner production using non-chlorinated alternative cleaners in parts cleaning of electroplating job shops. The approach describes the environmental and health effects associated with five chlorinated cleaning solvents through literature review, and develops an entirely systematic and comprehensive evaluation method to select non-chlorinated alternative cleaners.

The chlorinated solvents are environmentally unsafe. Trichlorotrifluoroethane and 1, 1, 1 -trichloroethane both play a significant role in the depletion of the ozone layer. 1,1,1-trichloroethane, trichloroethylene, perchloroethylene, and methylene chloride generate hazardous atmospheric air pollutants. These cleaning substances are also detrimental to worker health and safety. They negatively affect the central nervous system in a variety of ways causing symptoms such as headaches, dizziness, and fatigue. Skin and eye irritation are common symptoms that workers experience while working with these chemicals. The related epidemiological studies have shown that some of these chemicals may cause cancer. As a result of these findings, government agencies have strictly regulated the production and use of these chlorinated solvents. These regulations, therefore, have been the driving force toward cleaner production using non-chlorinated alternative cleaners. Six electroplating job shops were selected to quantify the various common substrate types to be cleaned and identify the common contaminant types. Based on the results, eight compatible alternative cleaners were chosen from Surface Cleaning Laboratory data base of the Toxics Use Reduction Institute in the University of Massachusetts Lowell. The two most effective alternative cleaners were selected from them using two rapid screening protocols.

The results of cleaning effectiveness were compared for the variables (soil and substrate types) in a TCE vapor degreaser and in ultrasonic and low pressure spray units using the two alternative cleaners. The environmental and health hazards for TCE and the two alternative cleaners were quantified by P20ASYS. Economic analyses of each option was performed using the total cost assessment method.

This study ascertained that the most common substrate types are steel, copper, and aluminum, making up over 90 % of the total. The most common contaminant types were metal working fluids and machining oils. TCE vapor degreaser removed almost 100 % (ave.~99.90 %). The two alternative cleaners had cleaning efficiencies greater than 100 %. They removed measurable amounts of the test sample coupons. The metal loss effect was stronger in alternative cleaner one (ave.=106.80 %) than alternative cleaner two (ave.=101.80 %). Metal loss was directly related to the cleaning method used; the ultrasonic method was found to cause more metal loss than the low pressure spray method.

The final hazard scores of P20ASYS showed that TCE is much more hazardous than the two alternative cleaners selected. This study found P20ASYS to have shortcomings in evaluating the potential hazards, i.e., it was enforced to rely on assumptions, there was limited hazard data established for the alternatives, and many of the quantitative/objective input values were disregarded in favor of the qualitative/subjective ones. Therefore, the scores determined by this study can be inaccurate to some unknown degree. Therefore, a new method of P20ASYS was developed that requires all input values be used in calculating the hazard scores. The quantitative/objective data is no longer influenced by the qualitative/subjective data. The new method is most accurate when all data about each mixture as -a whole is available.

This study also found that the use of non-chlorinated alternative cleaners is much more cost-effective than that of the chlorinated cleaning solvents. This study demonstrates that it is possible to develop alternative cleaning methods for electroplating job shops that are effective, safe and efficient.

Wallace, Arthur T. (1998)
Title: Materials accounting as an environmental performance indicator for industry
Abstract: Public disclosure of information on toxic chemical releases from industrial facilities has generated public pressure to reduce pollution. Environmentalists propose that industry should report on process inputs and materials incorporated into products as well as releases and wastes. This practice is referred to as mass balance or materials accounting reporting. Opponents dispute that materials accounting provides a superior measure of environmental performance, and cite the risk of revealing confidential business information.

Some companies use materials accounting internally to track environmental performance. The case study method is used in this research to examine how three Massachusetts companies in the scientific, photographic and control equipment industry use materials accounting to measure environmental performance, and what added belief Its materials accounting can provide. The question of confidential business information is examined to determine whether the benefits of materials accounting can be achieved without causing competitive harm to reporting industries.

For the companies studied, materials accounting is shown to be useful for validating data on environmental releases and for encouraging pollution prevention. Its utility is not demonstrated for other applications: analysis of product environmental impacts, occupational risk, or emergency planning. There are some concerns about protecting confidential business information in these companies, but none has prevented disclosure of materials accounting data reported under the Toxics Use Reduction Act.

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Epidemiology

Bardin, Judith A.: ScD (2000)
Title: Studies of pancreas, liver and biliary cancer in a cohort of automobile workers exposed to metalworking fluids
Abstract: The General Motors/United Auto Workers (GM/UAW) cohort of 46,400 autoworkers is the largest study to date of workers exposed to metalworking fluids (MWFs). Subjects are comprised of all workers at three auto parts manufacturing plants in Michigan who worked for at least three years between 1941 and 1981. Although the majority of the cohort is comprised of white males, 17% of the workers are black and 10% are female. An extensive historical exposure assessment has been conducted. Cumulative aerosol MVVF exposure in mg/m3-years to the different types of MWFs (straight, soluble, synthetic and semisynthetic), and operations (grinding and machining) has been estimated. Exposure to additives and contaminants (aluminum, biocide, ethanolamine, triethanolamine, iron, nitrosamines and steel) has also been quantified by duration of exposure in years.

At the end of the second follow-up period in 1994, a third of the cohort are deceased and elevated standardized mortality ratios (SMRs) for pancreatic and hepatobiliary cancer are found at all three plants and among both blacks, whites, and females. Previous investigations in the cohort have found excess risk for several digestive cancers (larynx, rectal, esophagus and stomach) associated with MWF exposure, therefore the elevated rates of pancreatic and hepatobiliary cancer are of concern.

This research will consist of four separate studies: A pilot case-control study of pancreatic cancers identified by death certificate through 1984 (the initial follow-up period); a cluster investigation of black pancreatic deaths occurring at Plant 1; and two case-control studies of registry determined pancreas and hepatobiliary (liver and biliary) cancer based on an extension of follow-up through 1994. Conditional logistic regression models will be fit to estimate exposure response relationships

Both cancers are considered in the same proposal for two reasons: the organs share a close anatomic and physiologic relationship, and the occupational health literature suggests similar risks in related industries. The cancers share a particularly grim prognosis with an average median survival of three to six months after diagnosis. Treatment is infrequently curative and at best only modestly palliative. Prevention may be one of the few means to reduce mortality. Elucidation of risk factors is therefore of utmost importance.

Dhara, V. Ramana: ScD (2000)
Title: Bhopal gas leak: lessons from studying the impact of a disaster in a developing nation
Abstract: A review of the health effects of the 1984 disaster in Bhopal, India shows continuing morbidity of a multi-systemic nature in the exposed population. Scientific debates about the causes of the accident, the spectrum of health effects, and toxicology are presented with a view to understanding the toxins released in the gas cloud and their role in the causation of health effects. Clinical dilemmas, medical management, and epiderniologic issues are also discussed. An insight is provided into the national and trarisnational implications of the disaster. Further examination of the effects of exposures from the disaster after 10 years was undertaken among a cross-section of current residents and a subset of these with persistent symptoms. Individual exposure estimation was done for gas victims by developing exposure indices based on activity, exposure duration, and distance of residence from the plant. Exposure-response relationships were examined using the exposure indices to determine which of these were useful in predicting health outcomes of respiratory and non-respiratory symptoms, and pulmonary function. Though none of the six indices developed were consistent in predicting all respiratory symptoms as well as all measures of pulmonary function, Total Exposure weighted for Distance predicted most respiratory symptoms, one measure of pulmonary function in the crosssectional sample, and two measures of pulmonary function in the symptomatic subset. Other major chemical incidents were reviewed to note some of the common problems associated with public health investigation of disasters. Some of these included the lack of accident-related and toxicologic information, expertise, and funds to conduct investigations. The complexity of the Bhopal crisis was underscored by the severe mortality and morbidity as well as its occurrence in a developing nation which had little experience in dealing with chemical disasters. Lessons learned from the disaster are discussed along with recommendations for disaster preparedness, long-term monitoring, rehabilitation, and treatment of the gas victims.

Thompson, Deborah: ScD (2000)
Title: Occupational exposure to metalworking fluids and risk of breast cancer among female autoworkers
Abstract: This epidemiologic study evaluated the potential association between occupational exposure to metalworking fluids (MWF) and risk of female breast cancer. MWIF are commonly used throughout the metals manufacturing workplace to cool and lubricate parts while metals are cut. Exposure to MWF occurs through the deposition of chemical mists on the clothing and skin of workers as well as through inhalation, ingestion, and dermal contact.

Many of the components of MWIF are known or suspected carcinogens. Polyaromatic hydrocarbons (PAHs) found in trace amounts in straight and soluble particulate, and N-nitrosamines formed in synthetic MWF are cocarcinogens. The biological hypothesis of this study was that toxic components of MWIF (PAHs, biocides, nitrosamines, chlorinated paraffins) interact structurally and dynamically with the female endocrine system, increasing the risk of disease. Recent investigations have described certain exogenous chemicals as endocrine disruptors; many endocrine disruptors are carcinogens.

This case-control study of breast cancer was nested in a cohort of 4,680 female automobile workers employed in Michigan. Preliminary analysis and other recent data suggested a positive association between breast cancer mortality and exposure to MWF. In this analysis, incident as well as mortal cases were identified through cancer registries, and information on non-occupational risk factors was collected through questionnaires. The cohort was accompanied by a comprehensive and quantitative exposure assessment. The overall objective of this study was to estimate exposure-response associations between specific types of MWF and the incidence of breast cancer.

Preliminary findings were that exposed cases received twice the lifetime cumulative exposure to both straight and soluble MWF, compared to exposed controls (4.0 vs. 2.1 mg/m3 -yrs straight MWF, 7.2 vs. 5.0 mg/m3 -yrs soluble MWF). Odds ratios for total lifetime cumulative exposure to straight and soluble fluids were 1.04 (95% Cl: 1.00-2.44), and 1.16 (95% Cl: 0.78-1.71), per mg/m3-year of exposure to straight or soluble particulate, respectively. Temporal and biologic exposure windows were created in order to further understand this association.

Increased risk was identified with exposure to straight+soluble particulate in the decade preceding diagnosis (OR 1.06, 95% Cl: 1.01-1.10, per mg/m3 -yr exposure to straight+soluble particulate), and during the time interval between hire and menopause (1.65, 95% Cl: 1.07-2.54 per Mg/M3 exposure to straight+soluble particulate). Risk was most strongly associated with exposure in the period between hire and first full-term pregnancy (OR 2.84, 95% Cl: 1.24-6.51 per Mg/M3 of exposure to straight+soluble particulate), although this reproductive window was subject to potential positive confounding.

This study reports preliminary findings, which, if confirmed by further studies, suggest that the standard now proposed by the Occupational Health and Safety Administration for MWF may not be protective against risk of female breast cancer. Due to inherent limitations of the data and because this is the only study of the association between MWIF and breast cancer, these results must be interpreted with caution.

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Dodic-Fikfak, Metoda: ScD (1998)
Title: Lung cancer and exposure to chrysotile and amphiboles
Abstract: Considerable controversy surrounds the question of whether the two different types of asbestos -- arnphiboles and chrysotile -- have different carcinogenic potencies. The "amphibole hypothesis" holds that chrysotile is less likely to cause lung cancer and mesotheliorna than are the amphiboles. Some researchers have even argued that chrysotile is not carcinogenic. The ability to clarify this question is limited by a lack of quantitative data with which to estimate separate dose-response curves for the two fiber types. This work investigated lung cancer risk in a Slovenian asbestos cement plant in which excellent historical exposure data are available to distinguish the working lifetime exposures of the two broad classes of asbestos fibers for workers in the plant. Detailed historical exposure reconstruction and a case control study of lung cancer incidence were conducted.

The cohort of workers employed in the asbestos cement manufacturing plant of Salonit Anhovo, Slovenia was constructed from existing detailed wage lists which date from the 1940s. Cases were all incident cases of primary lung cancer from 1964 to 1994 in those who were hired after 1959 and who worked at least one month between 1964 and 1994. They were identified using data from the Slovenian National Cancer Registry, one of the oldest national registries in Europe.

Exposure measurements were available for all exposed jobs beginning in 1961. Three different methods of measurement were used: k6nimeter measuring particles/cm3, a gravimetric method measuring milligrams/m3, and membrane filter measuring fibers/cm3. Operation-specific conversion factors among these methods were developed to standardize the available airborne asbestos measurement. For the jobs and time periods lacking measurement data, the airborne concentrations of total asbestos, chrysotile and amphibole were estimated using production process records and interviews with longservice employees and factory managers, engineers, physicians and environmental managers. Cumulative lifetime exposures to amphiboles and to chrysotile were estimated separately for all cases and controls. Exposure histories were completed on all cases and controls.

For each of 67 cases, 5 controls were selected and matched by date of birth, gender, and hire pre or post-1959. Smoking data were obtained from all but one subject using questionnaire.

Logistic regression models were used to estimate separate exposure-response curves for the two fiber types, controlling for smoking. Results are mostly negative. In the period more than 15 years before diagnosis smokers above the 90%1le of either chrysotile (OR=1.8, 95% CI=0.7 - 4.7) or amphibole (OR = 2.2, 95% Cl = 0.9-5.5) had a somewhat higher risk than those with lower exposure. There was also weak evidence that exposure to chrysotile more than 35 years prior to diagnosis was associated with an excess risk of lung cancer (OR = 2.2, 95% Cl= 0.4 -11.9).

The lack of strong evidence of an association between asbestos exposure and lung cancer risk is likely due to the low levels of exposure in the earlier years of the plant. An additional ten to 15 years of following will not only add more cases but will also include cases relevant to the period of heaviest exposures in the 1970s and 1980s.

Sama, Susan R.: ScD (1996)
Title: Metal working fluids and acute respiratory responses
Abstract: Metal working fluids (MWF) are a common exposure in the metal manufacturing industries and have been associated with both chronic and acute respiratory health effects. Although these health effects have been described, more investigation is warranted to better define exposure-response relationships. Improved characterization of exposure is needed to identify causal agents within these complex mixtures, to better understand the physiologic mechanisms underlying the pathologic changes being described, and to devise methods of control to reduce these exposures.

This dissertation is based on a study of acute respiratory effects resulting from exposure to MWFs. The data collected on this cohort were examined in three separate investigations. The first examined the acute respiratory effects of airborne sulfur exposures. The second investigated the high prevalence of sinus symptoms observed in the cohort and the relationship between sinus symptoms and asthma. The third evaluated the usefulness of the peak expiratory flow (PEF) meter as a device to measure changes in pulmonary function, by comparing peak expiratory flow obtained from "mini-Wright" meter to two more commonly used tools: the spirometric forced expiratory volume in the first second (FEV,) and reports of respiratory symptoms.

Three hundred and eighty six workers in an automobile parts manufacturing facility participated in the investigation. This cohort included 216 machinists and 170 nonmachinists recruited from assembly areas, gauge rooms and office areas. On a single day, each worker performed pre- and post-shift spirometry, answered a standardized respiratory questionnaire and wore a personal sampling pump which measured their exposure (mass aerosol concentration). A subset of this cohort was selected and studied in a more intensive six-day longitudinal PEF study. These 48 machinists were asked to perform serial peak expiratory flow measurements on both work days and non-workdays (home days). Personal exposure measurements were collected on work days. In addition to personal exposures, descriptive industrial hygiene information was collected at each participant's work station.

After observing an association between cross-shift decline in FEV, and mass aerosol concentration, improved characterization of the exposure was sought through investigation of four elements of a priori interest (Cl, Cr, Ni, S). Of these, only sulfur showed an association with cross-shift FEVI decrement. The relative risk of >=5% cross-shift FEV decrement was 2.7 (95% confidence interval= 1.0-6.0) comparing those with >4.4 ug/m3 those with <2.5 ug/m3 sulfur exposure. Because the concentrations of sulfur in this environment were relatively low, and other respiratory irritants were present, sulfur is more likely to be an indicator of more irritating conditions than the sole agent responsible for the observed acute respiratory effects.

Sinusitis is well recognized in the clinical literature to be associated with the exacerbation and or development of asthma in the clinical literature. However there has been little epidemiologic examination of these relationships in occupational cohorts. Sinus symptoms were the most frequently reported of all the respiratory symptoms -- forty three percent of the participants reported having regular sinus trouble. There was suggestive evidence that sinus symptoms reported to be work-related were associated with asthma that had developed after employment (Prevalence Ratio (PR) = 2.7, 95% C.I. 0.7-10.0) and even stronger evidence of an association with asthma that had been diagnosed within the past ten years (PR = 6.6, 95% C.I. 1. 1-42.0). An association was observed between sinus symptoms and bronchitis (PR = 1.6, 95% C.I. 1.2-2.3). Sinus symptoms also demonstrated associations with MWF exposure. Machinists were 50% more likely to report symptoms than non-machinists (p = 0.001). Those workers with aerosol exposures greater than 0.08 mg/M3 were twice as likely to report sinus symptoms than those with exposures less than 0.08 mg/m3 (p < 0.01).

Peak expiratory flow (PEF) is being increasingly used in investigations of respiratory exposures and disease. In order to better evaluate its usefulness, the "mini-Wright" PEF (MWPEF) was compared to spirometric FEV, spirometric PEF (SPEF) and questionnaire reported symptoms. MWPEF and SPEF were strongly correlated (r = 0.85, p = 0.0001). SPEF was only slightly more correlated with FEV, than MWPEF (r=0.75, p=0.000 I versus r = 0.72, p = 0.0001). These measurements were then compared to each other in terms of their relationships with symptoms. The amplitude of the daily variation in PEF measured as a percent of the mean ("amplitude percent mean") was calculated from serially collected data using the mini-Wright meter. MWPEF was more comparable to FEV, in its relationships to symptoms than was SPEF. MWPEF was superior in identifying asthmatics and those that reported hayfever. The amplitude percent mean also successfully identified asthmatics. MWPEF for asthmatics was on average 8 liters/minute lower than that for non-asthmatics (p = 0.0008), while asthmatics had a 6% higher daily amplitude percent mean than did non-asthmatics (p = 0.0002).

I recommend that additional investigations of sulfur as an active agent in MWF be completed. The sulfur component of MWF exposure ought to be measured in future studies of machinists. Detailed chemical analyses are needed to identify the chemical species responsible for the sulfur effect. I also recommend that the proposed sinus questions be incorporated into regularly administered respiratory health questionnaires so that the relationships between sinus symptoms and asthma may be evaluated in other occupational cohorts. The timing of the onset of both sinus symptoms and the development of asthma can be used to address etiologic questions concerning these two conditions. I also recommend the use of portable peak flow meters in studies of respiratory exposures and disease. Future replication of the analyses of the relationships between PEF and other respiratory health measures presented in chapter V would be very useful, especially in terms of the relationship between PEF, asthma and hayfever. Studies that better describe the sources of variation in PEF would also be useful for developing better prediction PEF equations. These studies may clarify the physiological differences between PEF and FEV, measurements. It is clear that these two tests do not measure exactly the same thing, but the nature of these differences remain unresolved.

Wenzl, Thurman: ScD (IH/Epi, 1992)
Title: Estimating Worker Exposure to Power-Frequency Magnetic Fields
Abstract: Though exposure to power-frequency magnetic fields is now suspected of contributing to excess risk of adult brain cancer, few epidemiologic studies of this hypothesis have used workplace measurements to assign study subjects to exposure categories. Past studies have estimated exposure probabilities based only on job information. For a case-control study of brain cancer at a large automobile transmission plant, a strategy was developed to use two types of instruments to measure personal exposure to power-frequency magnetic fields. A representative group of 81 workers were asked to wear a data-logging dosimeter for one-half shift apiece. This instrument recorded 3-axis magnetic field values every 4 seconds. With little clarity about the biologic process which might connect these magnetic fields to cancer promotion, several indices summarizing exposure variability over time were computed. A new index of "jaggedness" was also computed, since some human studies suggest very uneven exposure profiles are the most biologically active, possibly via interference with melatonin synthesis in the pineal gland.

One minute average exposures were found to range over more than 4 orders of magnitude, from 0.12 to 1300 milliGauss (mG); half-shift averages fell between 0.14 and 46 mG with the highest values for workers near demagnetizers. The median of the half-shift average exposures was 1.3 mG. Comparisons between the several exposure indices showed moderately high correlations between indices which were sensitive to peak exposures, but other indices were less well correlated.

To test a simpler measurement strategy, a hand-held direct reading instrument was also used, with multiple measurements taken at the head and waist for most workstations. These were averaged and combined with time estimates to give 'built-up' average exposures. Correlations were high (r=0.8) between these built-up averages and averages derived from the datalogger records. Some workers had different estimated exposure at the head than at the waist, but at this plant no entire job title had this property.

It was possible to assign job titles to three distinct exposure categories based on measures of the central tendency of the distributions of measured exposures. By ranking job groups by their average exposures, electricians and non-production grinders were placed in a high exposure category, assemblers and material handlers were placed in a low category, and all other jobs were placed in a medium exposure category. Analysis of variance, with influence analysis, was used to determine that these categories had significant exposure differences from one another, and that these differences were not solely due to a few high exposure measurements.

Ergonomics/Safety

Gold, Judith Eileen: ScD (2002)
Title: Indicators of upper extremity musculoskeletal disorders: digital vibration threshold testing and infrared thermography
Abstract: Upper extremity musculoskeletal disorders (UEMSDs) such as carpal tunnel syndrome and tendinitis comprise a large percentage of workplace illnesses. However, options for screening, surveillance and diagnosis of UEMSDs are limited. Detection of UEMSDs other than nerve compression syndromes has depended on symptoms and on various clinical signs of undocumented validity and reliability. Other modalities including medical imaging and quantitative sensory testing (QST) are less well developed.

The objective of this thesis was to examine two potential indicators of UEMSDs -digital vibration threshold testing (VTT) and infrared thermographic imaging. Thermography detects cutaneous temperature, a blood flow surrogate. VTT reflects nerve functionality.

UEMSD signs and symptoms in automobile manufacturing workers (n 1187) were examined for their association with vibration thresholds (VTs) in cross-sectional analysis, and one year following such testing. Associations with workers' estimates of ergonomic stressors were also examined.

Three groups of office workers (n 29) underwent dorsal hand thermographic imaging before and after typing for nine minutes. Changes in mean dorsum temperature through several imaging periods were determined for controls and for subjects with distal UEMSDs, with and without subjectively cold hands exacerbated by keyboard usage.

VTs were associated with greater hand/arm numbness frequency in crosssectional analysis, and also with its persistence one year after VTT. VTs were also associated with de Quervain's disease and extensor and flexor compartment disorders, in cross-sectional analysis and in follow-up incident cases. Associations were found with hand force, vibration intensity as felt through the floor, and a sum of exposures.

Three distinct blood flow patterns in response to a typing challenge were seen in the three office worker groups. Warm cases and controls both increased mean dorsum temperature after typing, while cold cases decreased. An ambient temperature effect was seen in both cold cases and controls.

VTT may be useful in early detection of UESMD signs and symptoms. Further studies are necessary to assess its validity and feasibility for the conditions where associations were found. Longitudinal studies in larger case groups with detailed symptom characterization would clarify the utility of thermography in such early detection. Validity and feasibility measurements could then follow.

Rockefeller, Kathleen A.: ScD (2002)
Title: Evaluation of an ergonomic intervention in Washington state nursing homes
Abstract: This dissertation research was conducted as part of an ergonomic intervention study in Washington State nursing homes. A unique opportunity existed for government and industry to work together to address an important occupational health and safety concern. The overall goal of the intervention was to reduce the incidence and severity of work-related musculoskeletal disorders and injuries among employees in nursing homes, particularly nursing assistants (NACs). Epidemiological and biomechanical research suggested that manually caring for residents -- or the activity of "people handling" -- was particularly risky and associated with reported high levels of disorders and injuries. Ergonomic factors of awkward postures and heavy loads have been implicated. The objective of the partnership was to encourage nursing home facilities to implement programs that encouraged using mechanical devices to assist in handling residents. The strategy was to offer a financial incentive so facilities could reallocate resources to obtain equipment and simultaneously implement other key program components.

Work sampling observations of nursing assistants were collected, using the PATH method of ergonomic work sampling, at baseline and one year later in both "incentive" and "comparison" facilities. Results at baseline confirmed that exposure to awkward shoulder and trunk postures and heavy loads were common in nursing assistant daily tasks and activities. At follow-up, there was some suggestion of improved trunk posture in the incentive group. There was no improvement in shoulder posture in either group.

Over the same time frame, three annual surveys were sent to all nursing homes in Washington in order to assess the degree of implementation of so-called "zero lift" programs. Analysis of survey results indicated that newer mechanical equipment to assist in resident handling had become increasingly available statewide. Facilities that received the financial incentive invested in newer equipment at a faster rate than comparison homes, and rated themselves as having more key program components. The role of nursing home demographic characteristics, especially financial status and chain membership, were also examined with result to zero lift implementation.

Dybel, Gerard J.: ScD (2000)
Title: Ergonomic evaluation of work as a home health care aide: descriptive and epidemiological analysis
Abstract: The objectives of this research were to describe the work of a home health care aide using real-time observational techniques and to identify the location and prevalence of musculoskeletal complaints among workers in this group.

The first section of the study used the PATH observational technique and the Lumbar Motion Monitor to quantify the tasks, postures, and trunk dynamic motion characteristics of 30 home health care aides. Patient care tasks, in particular assisting with self-care, were observed more frequently than non-patient care tasks. Patient care tasks also had significantly greater trunk dynamic motion values than non-patient care tasks. Workers who were observed while using back belts had fewer non-neutral trunk postures and less extreme dynamic motion values. Workers providing care to patients having greater levels of disability were observed more frequently in non-neutral trunk postures and performing the tasks and activities with larger dynamic motion values.

The second study investigated the location and prevalence of musculoskeletal complaints for home health care aides and the comparison groups home care nurses and office workers. The Nordic Questionnaire and a supplementary questionnaire were given to 207 home care aides, 81 home care nurses, and 74 office workers. The prevalence of musculoskeletal complaints in nine regions of the body during the previous 12 months, the previous 7 days, and lost work time during the previous 12 months due to a musculoskeletal complaint was determined.

Home care aides had higher prevalence ratios when compared to office workers for lost work time during the previous year due to low back pain, knee pain, and ankle and foot pain. Home care aides who were taller had higher prevalence ratios during the past 12 months, previous 7 days, and for lost work time. Home care aides who reported participating in a strength training program greater than 3 day/week demonstrated a protective affect for low back pain during the previous 12 months, the previous 7 days, and for lost work time during the previous year.

The research demonstrated that home health care work exposes the care provider to numerous postural and work-related risk factors. When compared to workers thought to have a more sedentary job, home care aides reported an increased number of complaints in several regions of the body, as well as, increased lost work time. These results point to a need for additional research to investigate the effect of ergonomic interventions to reduce the risk factors associated with home health care work.

Forde, Martin S.: ScD (2000)
Title: Musculoskeletal disorders, ergonomic exposures, and construction ironworkers
Abstract: The main objectives of this research study were as follows: (i) to review several pathomechanisms that are potentially related to the disease process of musculoskeletal disorders (MSDs); (ii) to explore issues related to the design of exposure assessment tools and metrics that are better able to predict MSD health outcomes by incorporating knowledge of dynamic bio-physiological processes into exposure assessment protocols; (W) to characterize the ergonomic risk factors of construction ironwork (CI); (iv) to determine the prevalence of MSDs among unionized ironworkers; and (v) to propose exposure indices that could be incorporated into pathogenic process-driven models designed to predict adverse MSD health outcomes for Cl.

The first paper reviews current conceptual models used in relation to work-related musculoskeletal disorder (VVRMSD) pathology and then describes several pathomechanisms that may be relevant to the underlying disease process of WRMSDs.
In the second paper, the relevance of using knowledge of WRMSD pathology in designing appropriate exposure assessment metrics is discussed. A process-modeling approach is outlined that could be used to capture the dynamic nature of bio-physiological and pathogenic processes.

The third paper presents the results of a study to characterize the task content and physical risk factors in Cl. Qualitative and quantitative data for seven specific tasks selected from the four main specialties of Cl - Machinery Moving/Rigging, Ornamental, Reinforcing, Structural - are provided. The task and activity performed were consistently found to be major predictors of the frequency of non-neutral postures for the trunk, legs, and arms. Additionally, ergonomic exposure indices for each Cl specialty were calculated and are presented.

Finally, in the fourth paper, the prevalence of MSDs and doctor-diagnosed disorders (DDDs) among construction ironworkers for the four Cl specialties were determined. Detailed DDD and recent MSD symptoms data were obtained from a telephone-administered questionnaire given to unionized ironworkers. Results show the highest prevalence of self-reported MSD symptoms were for the lower back (56%) and wrist/hands/fingers (40%). The DDDs with the highest prevalence were tendinitis (19%) and ruptured disk in the back (18%).

This research argues for the importance to paying close attention to the design of exposure assessment tools so as to ensure that a better understanding between occupational exposures and health risks can be obtained.

Kittusamy, Nanda K.: ScD (2000)
Title: Characterization of ergonomic exposures among operators of heavy earthmoving construction equipment
Abstract: Although numerous studies have shown an association between operation of heavy construction equipment and symptoms of musculoskeletal disorders, very little research has been performed that characterizes the ergonomic exposures of operating engineers. It is believed that reducing ergonomic exposures, such as whole body vibration and postural stress, may be an important factor in improving the health, comfort and efficiency of these operators. The objectives of this study were to evaluate: 1) vibration at the seat/operator interface in three orthogonal axes; 2) transmissibility of vibration in the vertical axis; 3) psychophysical ratings of vibration level and vibration discomfort; and 4) postural requirements of the job. Vibration measurement and analyses were performed in accordance with the ISO 2631 standard. The psychophysical responses were collected using a visual analog scale. Posture was evaluated from videotape using the simulated real-time postural assessment system. The study was performed at several different construction sites in the Boston, Massachusetts area. Eight experienced journey-level operators employed by two major contractors participated in this study. The equipment evaluated for this study was categorized into three different sizes (small, medium, and large). The vibration levels and psychophysical responses were obtained both when the equipment was idling and performing dynamic tasks (e.g., digging). The postural requirements of the operator were evaluated only when the equipment was performing digging-related tasks. The results of this study indicate that the digging operation had higher levels of total weighted acceleration than high or low idling. The transmissibility data showed that the seat was amplifying vibration in the lower frequencies. Therefore the seats in the equipment may not be sufficient in protecting operators from long-term effects of vibration exposure. There was good correlation among the subjective ratings (vibration discomfort and vibration level), but weaker correlation between subjective ratings and quantitative vibration levels. The operator's subjective evaluation of discomfort from whole-body vibration appears to be a useful tool for quantifying the perceptions experienced by these operators. The postural evaluations revealed that the operators were required to assume awkward postures of the trunk, shoulders, and neck while performing their jobs.

MacDonald, Leslie A.: ScD (2000)
Title: Workplace stressors in mass production manufacturing: exposure patterns and associations with upper extremity musculoskeletal disorders
Abstract: A musculoskeletal epidemiology study was conducted in a mass production manufacturing environment involving detailed examinations of the distribution and range of exposure to physical and psychosocial job stressors and upper extremity musculoskeletal disorder (UEMSD) prevalence among white- and blue-collar workers. Participants were 410 (84%) of the 489 workers actively employed among selected work groups in July, 1995. Physical job stressors were assessed from questionnaire, direct observation and accelerometry. Psychosocial job stressors were assessed from questionnaire. UEMSD outcomes were ascertained by questionnaire responses to symptom characteristics by anatomic site.

A composite measure of physical load developed for surveillance purposes by the Occupational Safety and Health Administration was computed from worker and observer assessments, which were found to have moderate agreement. Exposure covarlation was found between selected physical and psychosocial stressors, and was especially strong in blue-collar production and low-status office work. Women in blue-collar work were more often employed in assembly line operations and, correspondingly, were exposed to higher levels of repetition. After adjustment, blue-collar workers with high composite physical load scores had more than a two-fold increased risk of UEMSDs. Compared to bluecollar workers with high physical load only, those also exposed to high Job strain had less co-worker support, greater group pressure, higher mental demands, less schedule control and a higher average composite physical load score. Workers in this mixed exposure circumstance had higher levels of anxiety and fatigue, less job satisfaction, and appeared to be at greater risk for UEMSDs, compared to those with high physical load only.

The composite measure of physical load was effective in identifying workers at greater risk for UEMSDs. Because stressors can be highly correlated in the workplace setting, there is a need for researchers to more explicitly consider exposure covariation in the generation and interpretation of study results. Considerable shared variance between stressors suggests that they manifest from common work organization factors governing the structure of work. Future research on work organization determinants of task-level stressors, and their coincident occurrence, may provide promising new insights into the nature of risk for UEMSDs.

Park, Jung-Soon: ScD (2000)
Title: Ergonomic exposure assessment and musculoskeletal disorders in automobile manufacturing
Abstract: Workers in the automobile manufacturing are at high risk to musculoskeletal disorders and exposed to a variety of ergonomic hazards. This research was to explore in-plant MSD medical visits for surveillance in automobile manufacturing and to address how to assess ergonomic exposures using workers' self-reports and systematic job observations.
In the first study, MSD medical visit rates and the level of physical ergonomic exposures were estimated by job titles. MSD medical visit rates were found to represent the combined outcome of workplace physical ergonomic hazards, workers' individual characteristics, and some work organizational factors (e.g., job control). Medical visits can be useful as MSD surveillance though they tend to underestimate the true magnitude of MSD at the workplace, and also as ergonomic hazard surveillance by linking them with a systematic job identification and ergonomic exposure assessment.

The second study on inter-method agreement found a weak association between workers' ratings of postural stresses at work and the frequency of non-neutral postures observed at their jobs. Musculoskeletal pain and other ergonomic exposures (e.g, force, high job demand) influenced workers' ratings to some extent. Further researches need to be carried out on the reliability and validity of self-reported exposures for different stressors, their exposure dimensions, and rating systems, against other valid exposure measurements. Factors that might change workers' perception and awareness of exposures need to be identified.

Job ergonomic observations are challenging for those performing non-routine tasks because of a potentially large amount of variability in task exposures and time spent at non-routine tasks. The third study proposed a method characterizing a population in a way that a conceptual guideline on ergonomic exposure assessment methodology and strategy can be provided (five categories of job routinization). The job observation approach was illustrated through an example of a large population with a mix of routinization. In the future, qualitative methodologies need to be developed to characterize the extent and sources of variability of non-routine jobs. Then, practical observation sampling strategies can be developed for those performing non-routine tasks. Also, more research on how to estimate time spent at non-routine tasks is needed.

Becerrill, Leonor A.C.: ScD (1999)
Title: Psychosocial risk factors among women workers in the maquiladora industry in Mexico
Abstract: The Maquiladora Export Industry (MEI) in Mexico is the widely spread manufacturing industry in the northern region of the country comprised of foreign-owned plants, which settled in Mexico from 1966 under the Border Industrialization Program. This thesis attemps to develop an analytic model and questionnaire tools to assess female maquiladora workers psychosocial job and outside-the-job environmental heath.

A four stage model was developed for analyzing the effects of macroeconomic policies adopted in Mexico on psychosocial worker's health and wellbeing in Chapter II. It assesses the impact to the changing psychosocial work and family environments from macro-level policies, work organization change, and migration factors. The need for developing appropriate instruments and measurements to evaluate the main stressors in both environments among this working population is developed from this model.

A study was conducted in two maquiladora factories in Sonora state, Mexico to develop the instruments and measurements for evaluating the job and outside the Job stressors. The study was based on qualitative group and individual interviews and a questionnaire. Regarding outside-the-job stressors, five new scales were developed (Chapter IV), these were, "housing" which correspond to the standard of living, "domestic responsibilities", "conflict relationships with family", "conflict relationships with friends", and "spillover between home and work responsibilities". All scales (job and outside-the-job) were tested using factor analysis and reliability tests. Results of these tests for scale construction and for evaluating the scales are presented in Chapters III and IV. The properties evaluated were: Scale construction (factor analysis), internal consistency (reliability), concurrent validity (bivariate correlation), disciminant validity (ANOVA test), and predictive validity (correlation, linear and logistic regression). 84 female workers participated in the qualitative interviews and 370 answered the questionnaire. Regarding the job stressors, the study developed a the Spanish version of the Job Content Questionnaire (JCQ) and evaluate its reliability and validity. Two new scales of social support from coworkers and supervisor were also developed. This study is presented in Chapter III.

The instruments developed in this research show significant validity and statistical power in predicting psychological strain outcomes. The outside-the-job stressors add significant predictive power beyond psychosocial work environment scales, for psychological strain. The scales are recommended for future studies among this workers population or other similar populations in developing Spanish speaking countries.

Paquette, Patricia D.:MS (1998)
Title: Occupational carpal tunnel syndrome surveillance in Massachusetts: a comparison of two reporting sources and an analysis of ergonomic exposure variables
Abstract: Cases of Occupational Carpal Tunnel Syndrome (OCTS) were reported to the Massachusetts Department of Public Health through physician reports and workers' compensation claims between March 1992 and June 1996. Additional demographic and descriptive data regarding occupational exposures were obtained from follow-up surveys. Incidence rates were calculated by the MDPH for age, gender, industry and occupation. A comparison of reporting source using interview data indicated significant differences with respect to severity, reporting lag time, surgical cases, and laterality. The addition of physician-reported cases was effective in finding new industries and occupations that might have otherwise been missed in the workers' compensation reporting alone. Distributions of exposure source and job task are given for the survey dataset by industry, occupation, and gender. There was an insufficient number of survey respondents within those industries and occupations with elevated incidence of OCTS; additional demographic and exposure information should be gathered.

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Paquet, Victor L.: ScD (1998)
Title: Assessment of ergonomic exposures in construction work
Abstract: The objectives of this research were to evaluate the validity of real-time observational assessment of body postures and to provide information needed for improving ergonomic exposure assessment strategies in construction work.

The first study involved the development and evaluation of an electronic direct postural measurement system designed to measure shoulder, knee and trunk postures. In a laboratory study on 5 subjects, the electronic inclinometers predicted shoulder, trunk and knee flexion to within 5 to 10 degrees of accuracy and the lumbar motion monitor (LMM) predicted trunk lateral bending and torsion to within 3 degrees of accuracy with no or very simple calibration procedures.

The second study involved the evaluation of discrete-interval observations for the assessment of body postures during construction tasks, by comparing categories of body posture recorded with two work-sampling approaches (PATH and a simplified version of PATH) to measurements obtained with the electronic postural assessment system and video analysis. Five subjects were each observed performing 3 of 6 simulated construction tasks. Overall, agreement among the work-sampling and the electronic methods was high, although there were some notable differences in the measured frequency of some leg and trunk postures.

The third study involved the evaluation of the efficacy of the task-based assessment approach through the examination of between-worker and within-worker components of exposure variability in a sample of construction tasks. In addition, bootstrapping (a computer resampling technique) was used to evaluate how the number of days of assessment affected the reliability of the exposure measure for groups of workers performing the same task. Exposures often varied greatly among tasks of a construction operation, indicating that the task-based approach is useful to improve precision in exposure assessment. The between-worker component of exposure variability, for the most part, was much smaller than the within-worker exposure variability over several days, supporting the hypothesis of high day-to-day exposure variability during construction work. Bootstrapping revealed that low frequency exposure variables may require as few as I or 2 days of assessment (particularly for low-variability exposures), while exposures with higher frequency may require 6 or more days (particularly for high-variability exposures) to allow a reliable assessment of exposure frequencies for construction tasks.

This research demonstrates how work sampling approaches can be used to obtain valid and reliable measurements of ergonomic exposures. The results have implications for both the evaluation of control measures in the work place and for exposure assessment in epiderniologic studies.

Warren, Nicolas: ScD (1997)
Title: Organizational and psychosocial bases of cumulative trauma and stress disorders
Abstract: The goal of this research is to expand knowledge of work organizational and psychosocial risk factors for stress-related and musculoskeletal occupational illness. The Investigation analyzed a large questionnaire-based data set, the Monitor Study, collected in the Netherlands. This Study consists of complimentary employer and employee data sets. Several levels of findings are presented.

I. Individual-level analysis of the employee data set. Psychosocial and biomechanical stressor levels show separate effects and clear interaction effects in their associations with strain and health-related outcomes. Psychosocial stressors show moderate but consistent associations with musculoskeletal strain, their associations are more prominent with pain reports and health-related outcomes. Each stressor demonstrates an individual pattern of associations, perhaps related to the physiology of their effects.

II. Company-level associations of organizational structure and culture with the individual-level psychosocial and biomechanical stressors--an etiology of risk ('actors. Industrial branch membership is strongly associated with increased levels of all 11 stressors analyzed. Other significantly associated company-level measures: type of workers compensation coverage-, percentage of temporary workers employed, and employer involvement in health and safety.

"Discrepancy Variables", the differences between employer and employee estimates of risk level, were created as hypothesized measures of organizational culture characteristics. They were found to have a strong dose-response relationship with individual stressor levels.

III. Company-level associations of organizational structure and culture with the individual-level dependent variables of strain, pain and health-related outcomes. These associations are strong but are found to operate almost entirely through individual-level stressors.

These findings have implications for prevention activities. To be maximally effective, " full- spectrum", integrated interventions should a) address the combination of psychosocial and biomechanical stressors in the work place and b) address organizational stressors, in a multi-level strategy to control root causes Of Occupational injury. This research suggests several marker measures that could be used to "flag" organizations at risk, guide interventions, and assess their results. The Discrepancy Variables, in particular, are expected to be the basis of a new set of tools useful for prevention strategies.

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Perez, Graciela M.: ScD (1996)
Title: Study of the effect of a wrist orthosis on peak grip strength, extrinsic flexor and anterior deltoid electromyography, and posture of the upper extremity
Abstract: A pilot was undertaken as an initial attempt to determine the effect of wrist splints on exertion level in a work environment. Peak grip strength (PGS) was evaluated with and without a wrist splint and found to decrease an average of 9.5 (5.6) percent for 6 workers who were accustomed to wearing a splint at work, and 13.4 (2.6) percent for workers who had not previously worked with wrist splints.

In addition, extrinsic flexor and anterior deltoid muscle activity (EMG) were evaluated in three workers while they worked with a splinted wrist and again as they worked with bare wrists. The mean extrinsic flexor EMG increased an average of 62.0 percent, as a result of the use of the wrist splint, for the three subjects, who performed a stuffing or weighing task. Mean anterior deltoid EMG increased an average of 48.6 percent. However, the variability within the EMG results suggested the need for a larger and more controlled study.

The objective of the second study was to examine the effect of the wrist splint on PGS using a larger study population than in the pilot. Ninety-six subjects (42 females) were tested for PGS, with and without the use of a wrist splint. PGS decreased an average of 13.7 percent for all subjects with the use of a wrist splint. Women in this study experienced twice as much decrease (18.5 percent) in peak grip strength as men (9.9 percent). Men under the age of 40, as a group, experienced an small (insignificant) percent increase in peak grip strength. Hand length was the best predictor of the effect of the splint on peak grip strength for all subjects, but could not explain the results for males under 40 years old.

The third paper involved a controlled, laboratory study that included 20 subjects. The objectives of this study were to evaluate: 1) muscle activity via electromyography (EMG), 2) posture of the wrist via goniometry, 3) posture of the shoulder via video tape analysis, and 4) perceived exertion (RPE) and discomfort (RPD) via rating scales, during a simulated occupational pick and place task.

The laboratory study showed that mean extrinsic flexor EMG was increased, on the average, 37.4 percent for all subjects as a result of the use of a wrist splint. Anterior deltoid EMG increased 12.5 percent for all subjects, but males experienced more than twice the increase as compared with females. Although subjects were splinted at 30 degrees of extension, the mean angle during the pick and place task was kinematically neutral and the range of motion for flexion/extension was an arc of approximately 30 degrees. The ranges of motion (flexion/ extension and u1nar/radial deviation) of the wrist were markedly reduced, but not eliminated, during the pick and place task with the application of the wrist splint. In addition, elbow elevation was significantly increased with the use of the wrist splint.

RPE and RPD were decreased for the wrist and increased for the shoulder, while wearing a splint. Since the range of motion of the wrist decreased and the range of motion of the shoulder increased, the rating of perceived exertion may be associated with the degree of movement about a joint.

Franklin, Elise: MS (1994)
Title: Asphalt fume and OSHA standard-setting: Corporate ascendancy in rule making

Hathaway, James: MS (Ergo/IH), Instructor, Massachusetts Maritime Academy
Title: Measurement of grip strength utilizing force sensitive resistor technology

Joffe, Miriam: MS (1994)
Title: Health and safety benefits of an ergonomic intervention: a case study of a ball bearing manufacturing plant

Dropkin, Jonathan: MS (1993)
Title: A force comparison among three similar hand tools and two different wrist postures

Fulmer, Scott: MS (1993)
Title: A descriptive study of work exposure and health status among fisherman in Gloucester, MA

Lee, Diane: MS (1993)
Title: A work sampling method for the construction industry

Valorose, Scott: MS ( 1993)
Title: Orientation angles of the thumb trapeziometacarpal joint

Pentikis, John: MS (1991)
Title: An ergonomic evaluation of Massachusetts Water Resource Authority Workers

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Occupational and Environmental Hygiene

Ahn, Kwangseog: ScD (2003)
Title: An investigation of laboratory fume hood performance with an emphasis on the effects of worker movements and work practices
Abstract: This research addresses the relationship between laboratory fume hood performance and various aspects of its design and use, with an emphasis on the effects of worker movements and work practices. The objectives of this study were 1) to investigate the effects of various factors, particularly worker movements, work practices, and environmental conditions, on laboratory fume hood performance, and 2) to develop a new quantitative test method for laboratory fume hood testing.

This dissertation consists of three parts: a review of published quantitative experimental studies on factors affecting laboratory fume hood performance (Chapter 2 and Chapter 3); effects of upper body movements, work practices, and environmental conditions on laboratory fume hood performance (Chapter 4); and a new quantitative method for testing laboratory fume hoods (Chapter 5). Chapter 6 summarizes the findings of each part of the dissertation.

The review study found that hood failure was greatly affected by the presence of a mannequin/worker, distance between source and breathing zone, sash height/sash opening, and hood testing method. Results suggest that the use of face velocity may not be an effective evaluation tool for hood performance in the absence of other information.

The upper body movement and work practice factors tested in this study affected the measured concentrations in front of the worker. Sash opening was found to be the most important factor among the tested factors. Cross flow reduced the concentrations in front of the worker although it may result in bystander exposures within the lab. Upper body movement greatly affected hood performance reflecting the complex nature of airflow patterns and air contaminant transport inside the hood. Thermal load and hood clutter were relatively insignificant factors.

A new quantitative method using dry ice, warm water, and a carbon dioxide direct reading detector was developed for testing in-use laboratory fume hoods. This method is much easier to use, cheaper, and less time consuming than the ASHRAE 110 tracer gas test method and it may be used as an effective evaluation tool for hood performance. The hood test results using the dry ice method were comparable to the results using the ASHRAE 110 method under the specified conditions and test setup.

Bello, Dhimiter: ScD (2002)
Title: Determination of polyisocyanates in occupational environments
Abstract: The main focus of this dissertation is determination of polyisocyanates in workplace environments. This dissertation is comprised of four manuscripts.

The first paper discusses two major issues with polyisocyanates in occupational environments: the exposure metric and the standards. Based on isocyanate bulk analysis and a detailed documentation of problems with current bulk mass metric it was concluded that isocyanate exposure should be standardized on the total NCO content of the sample. With regard to regulations, current standards were compared and advantages and limitations were discussed. Based on a comprehensive review of the toxicological literature and for other pragmatic reasons, the paper suggests promulgation of a universal NCO-based polyisocyanate standard separate from the monomers.

The second paper evaluated the performance of the NIOSH draft method 5525 for analysis of aliphatic isocyanates in auto body repair shops. The method uses 1 -(9-anthracenylmethyl)piperazine (MAP) as the derivatizing reagent. The study concluded that the MAP method offers some significant advantages to other methods, such as enhanced resolution, increased sensitivity and selectivity, ability to measure the total NCO content of the sample, and a constant ultraviolet response of the MAP-isocyanate derivatives, regardless of their origin. For these reasons the MAP method should become the standard isocyanate method of its class.

The third paper investigated the ability of MAP-impregnated filters for sampling of aliphatic HDI-based isocyanates in a side-by-side field comparison with impingers. It was concluded that MAP-impregnated filters could be successfully used for sampling of aliphatic isocyanates.

The fourth paper reports on the development of a new analytical method for polyisocyanates, using 1 ,8-diamononaphthalene (DAN) as the derivatizing reagent. The DAN method works on a novel principle. The method quantifies perimidone, a single analyte, which is a measure of the total NCO content of a sample. The draft method developed worked very well with the class of aromatic isocyanates, and aliphatic monoisocyanates and diisocyanates, but not with aliphatic polyisocyanates. Further method development and validation is required.

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Kalil, Andrew J.: ScD (2002)
Title: Use of a work sampling method (tvea) to characterize determinants of particulate exposure in heavy and highway construction
Abstract: Particulate exposures undoubtedly play a key role in the higher rates of respiratory disease experienced by construction workers. In spite of this, the difficulties of exposure assessment in construction have contributed to a gap in understanding of the factors that influence air contaminant concentration during construction work. The overall objective of this dissertation was to identify and describe potential determinants of exposure to respirable quartz in a population of heavy and highway construction workers.
The first paper describes a work sampling based approach to exposure assessment. Time Variant Exposure Analysis (TVEA) is used to systematically survey over 30 potential exposure determinants that could affect exposure to three types of particulate. Two field studies were conducted to address questions of inter-rater reliability (n=20) and coding interval appropriateness (n=21) for the TVEA method. Substantial inter-rater agreement was obtained for most of the TVEA determinants. Regression statistics indicated that while 30 mm is an acceptable interval between observations for exposure assessment, 15 mm optimizes precision and practicality.
The objective of the second paper was to describe potential respirable quartz exposure during heavy and highway construction work. Processes with the potential for concrete exposure occurred for every operation (n>4), ranging from specialized foundation work (2% of workers) to demolition where 100% of workers were observed. Results indicated that the potential exists for bystander exposures for trades not associated with concrete work as 27% of these workers were in presence of concrete processes as a bystander a median 28% of the workday.
The objective of the third paper was to quantify the relationship between specific exposure determinants and respirable quartz levels. When the percent of the workday spent performing concrete work was greater than 50% more than half of the laborers had exposures greater than the NIOSH REL of 0.50 mg/in3. The two multiple regression models developed were able to explain 50% (categorical model) and 60% (tool/machine model) of the variance in quartz exposure levels. In both models, type of enclosure (complete or partial) and environmental factors (temperature and relative humidity) were significant, highlighting the importance of considering the construction environment during exposure assessment.

Irwin, III, William E.: ScD (2002)
Title: Radio frequency radiation risk a study focused on wireless telephones
Abstract: The focus of this dissertation is radio frequency radiation (RFR) from wireless telephone handsets and the risk assessment conducted for purposes of protecting health from this RFR. In the United States, the Federal Communications Commission (FCC) promulgates and enforces occupational and public health exposure limits for wireless telephone handsets. The FCC has relied upon the risk assessment of the Institute of Electrical and Electronics Engineers (IEEE) Standards Coordinating Committee 28 (SCC-28) in crafting these exposure limits. Using qualitative research methods of policy analysis, the procedures used by SCC-28, the people who make up SCC-28, and the results of SCC-28 efforts were evaluated. The objective was to determine if SCC-28 adequately evaluated wireless RFR health effects research to substantiate its partial body exposure limit recommendations, those pertinent to exposure of the human head from wireless telephone handsets. This is critical because the SCC-28 recommendations have been the primary basis for FCC regulations on exposures from the wireless telephone handsets.

The research methods employed were a systematic evaluation of published and unpublished comments and interview. The systematic evaluation of published and unpublished comments consisted of an analysis of records of activity in the minutes of SCC-28 as well as the collective perspectives of other knowledgeable individuals and groups in publications. This evaluation also included an in-depth literature review of hundreds of primary research publications designed to assess the nature and quality of wireless RFR health effects data available to risk assessors. Interview was accomplished using a detailed questionnaire. The National Academy of Sciences (NAS) criteria for risk assessment in the federal government were used to as the framework with which to assess the functions of SCC-28. To assess the recommendations of the results of SCC-28 risk assessment, the RFR health effects research literature was analyzed. This analysis examined whether evidence of risk was available and adequately considered in light of the judgements of authoritative individuals and organizations.

The findings of this investigation were that SCC-28 is composed of experts who historically have rigorously assessed the risks of RFR. The procedures of SCC-28 are generally in keeping with the NAS risk assessment criteria, but there exists the potential for significant conflict of interest among the most active members and the interests of the public were seldom considered. The scope of work before SCC-28 is such that risk assessment results may be diluted for the particular form of exposure from wireless telecommunications handsets because SCC-28 is designed to provide safety guidance for all forms and sources of RFR. This weakness is especially undesirable in an era of increasing numbers of people who are exposed to RFR from wireless telephone handsets for increasing amounts of time.

Review of the health effects literature does not indicate significant risk from wireless telephone RFR, though much more research and risk assessment is needed to rule out low levels of risk. This finding was in agreement with the IEEE standard for RFR safety, and the findings of the U.S. FCC and Food and Drug Administration, the International Commission for Non-Ionizing Radiation Protection of the World Health Organization, the Royal Society of Canada, the National Radiological Protection Board and Independent Expert Group of the United Kingdom and numerous other expert groups and individuals.

It is recommended that a precautionary approach be applied to wireless telephone RFR risk assessment and risk management. The precautionary approach, according to Kriebel et al (2001) encourages preventive action in the face of uncertain risks, a shift in the burden of proof to an activity's proponents, increased participation of the public in making decisions, and exploration of a wide range of alternatives to possibly harmful activity. This precautionary approach is recommended especially because of the uniqueness of wireless handset RFR exposure, including its close proximity to the head, intensity of exposure relative to other sources of RFR exposure, relatively brief time in the marketplace and the large number of people exposed, some for long periods of time.

It is recommended that a panel of experts with low potential for conflict of interest meet promptly to quantitatively assess risk particularly from wireless telephone RFR using all available relevant health effects information. The literature review conducted here indicated that there are many excellent research reports from respected laboratories and scientists which deal specifically with the molecular, cellular, and non-human and human responses to RFR from wireless telecommunications handsets. Specifically, this panel should be composed of equal numbers of academics and health care professionals who do not design or market wireless RFR sources and regulated users who do. The objective of this "blue ribbon panel" should be a rigorously defensible human exposure limit to which wireless handset manufacturers must demonstrate compliance.

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Cashins, Lisa J.: ScD (2001)
Title: Exposure assessment of synthetic textile dust generated during the finishing of polyester fabric
Abstract: This dissertation investigated workers' exposures to synthetic textile (ST) dust during the finishing of polyester fabric and identified the characteristics of the dust potentially related to the workers' respiratory health concerns. The dissertation has three parts: (1) the development of air sampling and analytic methods to evaluate regional ST dust lung deposition, (2) the determination of the chemical and physical composition of the ST dust, and (3) the modeling of workplace exposure determinants to identify effective engineering controls.

The first part of this research compared the ST dust exposure measures of mass concentration, fiber number concentration, and particle number concentration among three air sampling devices: the closed-face cassette (CF), inhalable IOM, and TSI Respicon Virtual Impactor. The Respicon collected more of the particles and fibers of' the ST dust than the IOM and CF. The Respicon sampler is also designed to separate the inhalable mass concentration into four size ranges (respirable, tracheobronchial, thoracic, and extra thoracic).

The second part of this research involved determining the composition of the ST dust. Physically, the ST dust was a mixture of particles and fibers in size ranges that were capable of depositing anywhere in the lung, especially the respirable region of' the lung. Chemically, the ST dust particles were determined to be plastics, minerals, chemicals and chemical salts, rust and metals, soots, dyes, and organic debris. Also, 50% of the inhalable particles contained at least one element that had the potential to induce adverse respiratory effects.

The final part of the research focused on the generation and control of the ST dust in the finishing department of a ST mill. An inverse relationship was found between the voltage levels measured from fabrics as they exited each of the five finishing machines (tenter, perch, SAN, shear, and napper) and the amount of ST dust produced at each machine. In order to have the greatest effect in controlling the ST dust, engineering controls should be implemented to reduce the electrostatic charge of the fabric after it exits the shear machine and remove the dust from the fabric before it enters the tenter machine.

Roelofs, Cora R.: ScD (2001)
Title: Losing controls: the case for a preventive industrial hygiene
Abstract: The aim of this dissertation is to build the theoretical basis for a shift In industrial hygiene practice from control of chemical hazards in the workplace to the primary prevention of them through the reduction of hazards at the source through material or process changes. The field of industrial hygiene, while strongly committed to the concept of prevention, has been dominated by secondary and tertiary control approaches such as local exhaust ventilation and personal protective equipment. This dissertation explores the factors have prevented source reduction from achieving and maintaining greater prominence in industrial hygiene, including the economic, social, political and technical barriers have prevented industrial hygienists from recommending and implementing primary prevention interventions. Three integrated investigations are discussed in this dissertation. In Part 1: Prevention in Context: A review of hazard control and prevention, three studies explore the role and elements of hazard control and prevention in industrial hygiene "theory," practice and literature. The first surveys twentieth century industrial hygiene texts, the second reviews articles 1994-2000 published in the peer-reviewed industrial hygiene journals, and the third investigation presents the results of a survey of practicing industrial hygienists' perspectives and experiences of preventive approaches to workplace hazards. Part II: Process Change for Hazard Prevention: The case of methylene chloride, consists of two studies. The first is a set of case studies on the feasibility and effectiveness of source reduction as a response to the hazards of working with methylene chloride. The second discusses the findings of a survey of preventive practices among current and former large users of DCM in Massachusetts. Part III: A Comprehensive and Integrated Approach to Hazard Prevention, reviews Massachusetts toxics use reduction technical assistance and case studies for the impact of these environmental prevention initiatives' impact on the work environment. Despite barriers, the dissertation findings point to industrial hygiene as a field poised to recommit to source reduction. The concluding chapter describes a new theoretical framework supportive of this approach based in a comprehensive and dynamic understanding of problems and solutions; a precautionary and participatory mandate; and a cleaner production framework.

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Becker, Paul E. (2000)
Title: Modeling construction worker chemical exposures for compliance with OSHA permissible exposure limits An investigation of lead exposures to highway bridge maintenance workers

Rennix, Christopher P.: ScD (2000)
Title: The occurrence and risk of breast cancer among women in the U.S. Army, 1980-1996
Abstract: In a cohort of women who served on active duty in the U.S. Army between 1980-1996, 272 cases of invasive breast cancer were diagnosed. A preliminary occupational analysis of the incidence of breast cancer in enlisted women found a relative risk of 1.48 for those women whose most recent job had a moderate to high potential for exposure to selected organic chemicals when compared to those with Jobs with no or a low exposure potential. The exposure potential rating was provided by Army industrial hygienists using the U.S. Army Health Hazard Information Management System (HHIMS). In support of this case-control study, a quantitative Job exposure matrix was constructed using annual task-duration weighted concentrations estimated from more than 2,300 workplace airborne measurements. Of the 18 organic chemicals studied, formaldehyde was the only chemical with a sufficient number of exposed cases for analysis by conditional logistic regression. Complete occupational and reproductive histories were available for 98 cases and their controls. A breast tissue development model was used to select time windows to evaluate the role of timing of exposure in each woman's reproductive life and the occurrence of breast cancer. The case-control study found that women who had occupational exposure to formaldehyde and delayed the birth of their first child until after age 25 years had an adjusted odds ratio of 3.2 (95% Cl: 1.4-8.2) when compared to all other women in the study. These results were consistent with the hypothesis that organic chemical exposure occurring while breast tissue was in a proliferative stage might present more risk than exposure that occurred when the tissue had completed development.

Mohammed, Abbas Virji: ScD (1999)
Title: Characterization and control of bridge workers' exposures to lead during paint removal and bridge painting activities
Abstract: A cross-sectional study of 89 bridge painters from 13 worksites was conducted over a two-year period from 1994-1995, to investigate the reasons for persistent elevated blood lead levels. The worksites were evaluated for 14 days during which biological monitoring for blood lead and environmental sampling for ambient lead was conducted. Quantitative and qualitative information on the characteristics of the worksite, personal activities and hygiene, meteorological data, and lead abatement methods was gathered including interviews with workers and contractors. Multiple air samples were collected for tasks performed by the workers from each worksite. Workers were also required to keep a diary of tasks performed, duration of the task and the type of respirator used.

The overall goal of this research was to create and characterize an exposure index for lead for an epidemiologic study, and to identify effective control strategies to reduce lead exposure to the workers. This research has two parts to it. Part 1 deals with the creation and characterization of an exposure index for lead. Part 2 of this research focuses on identifying control measures to protect workers from over exposure, especially, the extent of protection provided to the workers by the use of respirators.

The aim in the first part of the study was to estimate each worker’s daily full-shift TWA exposures by taking the product of the mean task exposure levels and task duration reported on workers, daily activity-time diaries, and summing the product across all tasks performed on a given day. The above strategy requires tasks to be homogeneous in exposure, whose means are unbiased, precise, and represent the true exposure levels of all the workers assigned to it. Thus, this section describes the task exposure levels and their distributions, and evaluates the homogeneity of tasks by calculating their coefficients of variation and by estimating their components of exposure variability. Once the tasks were evaluated, each worker’s daily full-shift TWA exposures were estimated by summing the product of mean task exposure levels and task duration. The mean task exposure levels were obtained by taking the arithmetic means of the tasks (simple task-am), or by developing a multivariate statistical model to predict mean task exposure levels (model task-am). Two indices of the full shift TWA exposures were calculated for all the workers on all the workday based on simple task-am or model task-am. The two indices of full shift exposures were evaluated by regressing them against measured full shift TWA exposures (considered to be the gold standard). The two indices were also evaluated by examining their relationship with blood lead levels in univariate statistical models. When the two task based exposure indices were compared to the measured full-shift TWA exposure, the model derived exposure index performed better than the exposure index based on the simple means (R2 of 0.66 vs. 0.51). However, univariate models of blood lead levels with the two exposure indices showed the exposure index based on simple task means was a better predictor of blood lead levels. A third exposure index, the stein estimator, which is hybrid of the individual and group means, performed the best in the univariate model with blood lead levels (R2 of 0.17).

The aim of the second part of this study was to identify strategies for controlling worker exposure to lead. The effectiveness of respirator use among bridge workers and the personal, social and work-related factors that affected respirator use by workers were investigated. The effectiveness of respirator use was evaluated by comparing the task exposures to the OSHA PEL for lead, and calculating the percent of exposures above the PEL after accounting for respirator use. The appropriateness of OSHA specified respirators for the various tasks was evaluated by assuming workers always used the OSHA specified respirators for tasks. These results indicated that for some tasks, the OSHA specified respirators did not adequately protect workers. The protection factors required for tasks that would keep the exposures for 95% of the workers below the PEL were also calculated. The personal, social and work related determinants of respirator use by workers were also investigated to identify factors associated with respirator use. These factors can be used to develop more effective intervention and training strategies to reduce bridge workers exposure to lead.

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Somers, Carol A. (1997)
Title: In the eyes of the beholder: studies of workplace risk perception and social location

Rimmer, Thomas W.: ScD (1995)
Title: New method for measurement of hearing protector attenuation: bone conduction loudness balance
Abstract: A new method for the measurement of hearing protective device (HPD) noise attenuation was developed and evaluated. The procedure, bone conduction loudness balance (BCLB), utilized pulsed sounds delivered alternately by a bone conduction vibrator on the forehead of the HPD wearer and by a loudspeaker outside the HPD. The bone conduction sound was maintained at a constant level and frequency (high enough to avoid the occlusion effect) and the air conduction sounds (1/3 octave bands of noise) were varied in level by the HPD wearer to achieve a subjective impression of equal loudness. The difference in level between the sounds required to balance with the HPD on or off was defined as the attenuation.

After preliminary feasibility testing, the BCLB procedure was compared to the standard method, real ear attenuation at threshold (REAT) as specified by ANSI Standard S12.6-1984, for 32 subjects. For expandable foam earplugs, the mean attenuation measured by BCLB agreed with REAT within 1 dB below 2000 Hz and within 4 dB at higher frequencies. In addition, approximately 95% of all individual attenuation comparisons at individual frequencies agreed within ±10 dB. For other types of HPD tested (earmuffs, canal caps, and earmuffs combined with earplugs), the mean attenuation agreement was within 3 dB at most frequencies and within 5 dB at all frequencies. Comparisons of mean A-weighted attenuation by BCLB and REAT for broad-band noise of various frequency distributions showed no statistically significant differences for all HPD types tested, except for canal caps, for which BCLB measured 3 dB higher attenuation than REAT. BCLB results were not significantly affected by background noise at a level typical of industrial audiometric testing environments (35 dBA) nor were the results at 2000 Hz and below affected by background noise at the level of a typical office (53 dBA). No significant differences were observed between BCLB and REAT regarding administration time or repeatability. It was concluded that the BCLB method is well suited for field use due to its applicability to all HPD types, resistance to background noise effects, and good agreement with REAT.

Mao, Chengchen (1995)
Title: Formaldehyde exposures, acute pulmonary response and exposure control in a gross anatomy laboratory

Clement, Richard S.: ScD (1994)
Title: Evaluation of performance criteria and test methods by investigating the effects of temperature and humidity on the response of portable direct reading radiological instruments
Abstract: The American National Standards Institute (ANSI) N42.17A-1989 "Performance Specifications for Health Physics Instrumentation-Portable Instrumentation for Use in Normal Environmental Conditions" standard has been evaluated by investigating the effects of temperature and humidity on the response of 105 portable direct reading radiological instruments (45 beta-gamrna survey meters, 10 alpha contamination monitors, 32 neutron survey meters and 18 tritium-in-air monitors). The shift or change in response from a randomly selected cross section of instruments was determined experimentally in an environmental chamber at temperatures ranging from -10 to 500C and at humidity levels of 40 and 95% RH. Commercially available radiological instruments tested include the Eberline RO-2 and RO-3C ionization chambers; the Eberline E-530 survey meter with the Model HP-177C stainless steel Geiger Mueller (GM) wall probe; the Eberline PIC-6A and PIC-613 ion chambers; the Eberline ESP-1 survey meter with the Model HP-260 pancake GM detector; the Ludlurn 3 survey meter with the Model 44-6 stainless steel GM wall probe; the Eberline ESP-1, ESP-2, and PNR-4 survey meters with the neutron rem detector (NRD); the Health Physics Instruments (HPI) 2080 survey meter with the moderator (Mod); the Ludium 139 survey meter with the Model 43-32 air-proportional (AP) alpha detector; and the Overhoff 394-C, Johnston J-1 I I and J- I 10 tritium monitors. Results of 1128 temperature tests (1269 hours of exposure in the chamber) and 735 humidity tests (1890 hours of exposure in the chamber) are presented. The study shows that the standard's test requirement for temperature at or near the extreme conditions, and the test requirement for humidity at 95% RH may be too restrictive for instruments used in the work environment. Also discussed is the impact and practicality of the ANSI standard's performance criteria and test methods.

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Dembrowsky, John P: MS (1994)
Title: Silica and cobalt exposures in a foundry and evaluation of controls

Ginieres, Mike: MS (1994)
Title: Comprehensive health and safety ergonomic evaluation of a bicycle factory

Greenspan, Cathy: MS (1994)
Title: Health hazards associated with the use of vacuum pumps in chemical vapor deposition

Lu, Chihwei: ScD (1994)
Title: Exposure assessment and risk index development for asbestos exposures to school custodians
Abstract: The goal of this thesis is to develop a methodology to characterize the asbestos exposure of the custodians in the Boston schools and to developed a generalizable risk index applicable to school custodians in other school systems. The objectives of the thesis were accomplished by the following specific aims:

1. Sampling Strategy design: To develop a method to select a representative sample of Boston-City schools to investigate the probability of asbestos exposure to school custodians. The parameters to be evaluated are the condition of Asbestos-Containing Material (ACM), building construction year, and previously conducted survey data.
2. Assessment of Asbestos Exposure of School Custodians: To conduct a detailed ACM exposure assessment of school custodians by description of activities and air sampling.
3. Development of Models for Prediction of Asbestos Exposure: To analyze the results of exposure assessment in school custodians and try to determine whether a liner regression models is appropriate as a way of categorizing asbestos exposure potential. An attempt to develop a generalizable RI for schools did not meet with success due to the small number of schools surveyed.

Six representative schools were selected to obtain air samples for asbestos exposures. Twenty custodians were selected and evaluated in time-motion observations recording all their weekly activities (268 hours of direct observation). Airborne asbestos samples were taken cumulative for each activity. A combination of personal (41) and area samples (71) were collected for 268 hours and 402 hours respectably. NIOSH methods 7400 and 7403 were applied for sampling and analysis. Both fiber concentration and type (chrysotile asbestos) were identified.

The mean fiber concentration of the six activities identified, 0.0117 f/cm3 was measured as personal samples. The mean fiber concentration of area samples was 0.0072 f/cm3. The results suggest that activity was a key factor to affect custodians' asbestos exposure level. A linear equation was developed that correlates asbestos concentration with school parameters. This equation can be used to predict the Boston school custodians asbestos exposure level. A risk indexes (RI) was also obtained for each school. These empirical equations are only applicable to this study. Recommendations for future research to develop a general risk index are made.

Partial or total removal of asbestos containing material (ACM) would decrease not only the asbestos risk of custodians but also the collateral risk of all students and teachers present in the school environment.

Stanley, Mark: MS (1994)
Title: Indoor air quality (Barus and Holley building, Brown University)

Cichon, Frank: MS (1993)
Title: Evaluation of styrene exposure during boat building

Coghlan, Kevin: MS (1993)
Title: Evaluation of heat stress during asbestos removal operations

Johns, Mary Ellen C: MS (1993)
Title: Evaluation and control of Di-methylformamide exposures in a manufacturing operation

Lapato, Jane: MS (IH/Ergo, 1993)
Title: An ergonomic intervention for a word processor with cerebral palsy

Lombardi, Michael: MS (1993)
Title: Chemical health hazards in a semiconductor fabrication facility

O'Herlihy, Christopher: MS (1993)
Title: Evaluation of a two hood (slot-type) ventilation system designed to minimize styrene exposures

Goudreau, Linda: MS (1992)
Title: A design for reduction of trichloroethylene use in a metal stamping and finishing facility

Joaquim, Jeffrey: MS (1992)
Title: Hazard surveillance in oil, chemical, and atomic workers in Union refineries in Southern Texas

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Quinn, Margaret: ScD (1992)
Title: A biologically-based quantitative method for characterizing airborne fiber exposure
Abstract: Fiber dimensions and composition should be considered in addition to airborne fiber concentration when quantifying the fiber exposure hypothesized to be relevant to lung cancer risk. However, the relationships of dimensions and fiber composition related to carcinogenicity are not certain. An approach to construct alternative fiber exposure indices, based on hypotheses regarding the role of fiber size and composition in lung cancer was developed. These indices, collectively called the Hypothetically Active Fiber (HAF) Indices, are based on three basic principles of proposed biologic activity:

1. the fibers must be able to cause the cellular changes associated with tumor formation;
2. the fibers must be sufficiently durable to remain at the target site long enough to cause carcinogenic cellular changes; and
3. the fibers must be able to reach the target tissues in the respiratory tract.

An HAF index can be quantified for a particular air sample by calculating the proportion of all the fibers that meet a set of HAF criteria, the HAF proportion. A specific set of hypotheses regarding the role of fiber dimensions and composition were used to construct a particular index, HAF1. The HAF1 proportion was calculated for sixty air samples collected in a variety of settings in the Man-Made Vitreous Fiber (MMVF) industry.

The HAF1 proportion differed from the proportion of other types of fibers that were counted by standard fiber analytic methods in the sixty samples studied, and there was no consistent relationship among these measures. Thus the index of fibers hypothesized to be relevant for a study of lung cancer risk is not equivalent to the standard fiber concentration measures.

A method then was developed to adjust standard fiber concentration measures to the biologically-relevant HAF1 concentrations using proportions of fiber size distributions. It was hypothesized that these proportions of the fibers needed for the adjustment procedure could be estimated from certain key characteristics of the products being made and production processes operating when an air sample was collected. General linear models were used to identify the important product and process factors, and to quantify their relationship with the relevant proportions of the airborne fiber size distributions. Approximately eighty percent of the variance in the HAF1 proportion among the sixty air samples was explained by a model based on the nominal diameter of the MMVF product being produced, and the presence or absence of oil in the MMVF product.

These results suggest that hypotheses about the biologically active fibers in airborne fiber exposures can be quantified using an HAF proportion, and that this proportion can be estimated for historical air monitoring data. these methods represent a potential improvement in the exposure estimation for epidemiologic studies of lung cancer risk in the MMVF industry.

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Work Environment Policy

Penney, Jennifer L.: ScD (2002)
Title: Green jobs: Lab our-environmental collab orations in Australia and Denmark
Abstract: This research examines and evaluates the development, promotion and implementation of a variety of green job plans initiated by the Green Jobs Unit in Australia, and by the General Workers Union in Denmark during the 1990's. Both the Australian and Danish programs took place in the context of widespread international discussion of green jobs, and of the necessity to incorporate employment considerations into environmental policies and vice versa. This report provides an extensive review of the related international literature. It also investigates the strengths and weaknesses of a variety of practical programs to integrate employment and environmental policies. And it provides information on the collaboration of unions and environmental organizations - supported in both instances by national governments - to define common sustainability goals, and collaborating to achieve them.

Velazquez Contreras, Luis Eduardo: ScD (2002)
Title: A model for fostering sustainable university programs' effectiveness
Abstract: Trying to speed up the progress to sustainability, this doctoral dissertation is aimed at developing a state of the art model that offers a highly structured framework for visualizing the sustainable university system. This model shall assist universities to improve the effectiveness of their potential or current sustainability initiatives through the identification of strategies, opportunities, and institutional barriers.

To ensure that the sustainable university model is connected to the real world of those who will later have to implement and enjoy sustainability, findings on this dissertation are not derived from general concepts, but rather elicited from empirical data raised from eighty higher education institutions around the world.

A Mexican model for sustainability education and the ISO 14,001 framework are analyzed as two potential strategies for establishing and maintaining the sustainable university model. The discussion is based on each of the essential elements in both structures, which are reviewed in retail in order to expand our knowledge of how better to reach sustainability in higher education institutions.

Early experiences on campuses have demonstrated many opportunities, but also many problems to the successful implementation of sustainability programs. For that reason, this doctoral dissertation also focuses on the issues that are preventing sustainability in higher education institutions.

The sustainable university model provides a clear orientation on exactly what a sustainable university is about by the conduction of a systematic analysis to understand the development of sustainability in higher education institutions.

Barreira, Thais H. D.: ScD (2000)
Title: Labor activism and the promotion of a healthier work environment: the case of ergonomics in Brazil
Abstract: The main focus of this research project was the labor' s role in the formulation and implementation of Ergonomic Programs developed by joint committees. Qualitative research methods and a social historic approach were applied in two Brazilian instrumental case studies in the service sector: 1) the Private Banking Industry; and 2) the Cashiers' workplace in Retail Food Stores. In both cases, unions were involved in a policy-making process for the prevention of musculoskeletal disorders - MSDs through the application of ergonomic principles. it was found that the ability of both unions and the inspectorate agency to act effectively for a more protective work environment was limited. The policies formulated were not effectively implemented. Brazilian labor movement activism was constrained by external circumstances. There was a decrease in membership and therefore a tighter budget for union actions. Old labor achievements and workers' rights were threatened demanding an extra effort from the union to be maintained. Changes in production methods, in industry and workforce characteristics generated new union demands and forced the unions to promote fast changes in their agenda and OSH (occupational safety and health) issues were not a priority. Failures in the union actions with OSH concerns were also found. Most of the work on this theme was dependent on personal attitudes of unionists and was reactive. Many union leaders reported that OSH organizing threatens the current union leadership power. In addition, because MSDs primarily affected women, they did not receive support from male health professionals and male union leaders. Although the incidence of MSDs is also a product of ergonomic invisible hazards engendered by global and productive restructuring procedures at the point of production, these hazards remained unrecognized by many health professionals, union leaders and workers. Educational programs were required to promote organizing and raising awareness around at least three major issues: a) the right to work in a healthier work environment; b) new ergonomic invisible hazards, and c) gender issues. Furthermore, a successful implementation of a preventive program required worker empowerment and shared commitment between management, the state, unions, and health professionals.

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Campbell, Richard (2000)
Title: Planning without a public: legitimacy and action in toxics use reduction policy
Abstract: Environmental policyrnakers have shown an unmistakable interest over the last decade in forging new approaches towards industry that fundamentally depart from the traditional regulatory paradigm. Two trends in particular stand out in the emerging policy agenda: a delegation of important oversight roles to nongovernmental third parties, and a reliance upon voluntaristic measures, rather than traditional regulatory controls, to induce change in industry. This research investigates a landmark environmental policy in Massachusetts that follows these trends by requiring regulated facilities to prepare plans on ways to reduce the use of toxic chemicals in products or processes, and by introducing a nongovernmental policy actor known as the "toxics use reduction planner" to certify facility compliance. Because the policy requires plans, but actually seeks to encourage effective planning and the reduction of toxic chemical use, and because the skills and standing of the new planner role are tentative, the research argues that the hopes for policy success largely hinge upon the ability of planners to establish legitimacy as authoritative policy actors. Qualitative methods are utilized to explore the legitimacy issue, primarily semi-structured interviews with planners. The research finds that, unlike professional specialists, planners have a variety of subjective dispositions to their role, and varying levels of technical skill and authority. The research concludes that in positioning planners in a planning, rather than auditing, capacity, the policy environment undermines the sense in which the legitimacy of the planner is defined along public lines. Instead, the effectiveness of planners, in large measure, hinges upon the fit between the individual talents of those who assume the planner role and the degree to which host organizations enable planner skills to be realized.

May, David C.: ScD (2000)
Title: Measuring the impact of OSHA interventions
Abstract: This study examined the relationship between an OSHA Local Emphasis Program (LEP) in ergonomics and changes in the employer's ergonomic program, the incidence of carpal tunnel syndrome (CTS) and upper extremity cumulative trauma disorders (UECTDs). The OSHA program consisted of inspections between 1992 and 1995 in New Hampshire at worksites with a history of UECTDs.

Using the OSHA enforcement case files as a source of data, seven ergonomic program elements, thought to be useful in control of ergonomic hazards, were documented at each of these worksites during the OSHA inspection and examined for improvements after the LEP inspection. In 19 cases reviewed, 9 employers had 5 or fewer ergonomic program elements in existence prior to the OSHA inspection. Following the LEP inspection, improvement in each of the seven ergonomic program elements occurred in 47% to 79% of the worksites. Twenty six percent showed improvement in all seven elements. No worksite with a poor preexisting program (as measured by worksites lacking at least half of the major elements) failed to have at least five of the seven elements by the end of the review period.

OSHA-200 injury and illness logs were used to calculate incidence densities to compare before and after the LEP inspection in 15 worksites, The median percent decline was 56% for CTS and 9% for UECTDs. A nonparametric test was used to examine differences between pairs of incidence densities before and after the intervention. The differences were found to be significant for CTS changes, p=0.035. During the post review period, (average of 29 months) there were 25 fewer cases of CTS than expected among 14 worksites involved in the LEP.

New Hampshire workers' compensation claims for CTS were reviewed for the 22 employers involved in the LEP. The annual incidence was compared to the experience of all other New Hampshire employers. New Hampshire employers who had an ergonomic inspection at one or more of their worksites, experienced a decline in carpal tunnel syndrome greater than other New Hampshire employers. The annual decline of CTS in the LEP group of employers was 6 per 10,000 workers compared with 0. 5 per 10,000 for employers not inspected. The LEP group of employers were responsible for 18% of all CTS cases in New Hampshire in 1994. By 1997 their contribution had dropped to less than 4%.

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Tickner, Joel A.: ScD (2000)
Title: Precaution in practice: a framework for implementing the precautionary principle
Abstract: This research develops a framework and set of procedures to implement the precautionary principle in environmental decision-making in the United States. The principle was developed to guide decision-makers where threats of serious harm existed, yet scientific evidence was insufficient to determine their specific type and magnitude. While its interpretation and implementation have been debated in Europe for two decades, discussions about the principle are just beginning in the United States. Given substantial differences in the American environmental regulatory system, there is a need to translate precaution into a U. S. context.

The precautionary principle is conventionally discussed as containing two main components: action in the face of uncertainty; and placing the burden of proof oil proponents of potentially harmful activities. These components are examined through case study analyses of the Institute of Medicine Committee on Agent ()range and the New Chemicals Program under the Toxic Substances Control Act, including how they have been implemented and lessons for effectively applying them in environmental policy.

After, the ways in which science and policy interact to influence the implementation of precautionary principle are examined. It is argued that implementation of the Precautionary principle demands changes in both the way risk management decisions arc made and the way science is generated for public policy. These include broader hypotheses and interdisciplinary methods as well as explicitness about uncertainties.

The two main components of the precautionary principle lead its interpretation as reactive, based on analyzing and responding to problems rather than proactively seeking solutions. This runs counter to its origins in the German Vorsorgeprinzip, meant to stimulate careful planning and innovation. Following the Wingspread Conference oil the Precautionary Principle, two additional components have been added, to ensure both the principle's anticipatory analysis and preventive planning functions: assessment ()f alternatives and democratic decision-making structures. These refocus environmental policy on seeking prevention opportunities and increase the information base and legitimacy f decision-making processes. These components are analyzed, including examples of their implementation in environmental decision-making.

A framework and procedural steps to embed precaution in environmental decision making - precautionary assessment - are detailed. Influences, barriers, and opportunities for implementing such a structure in United States environmental regulatory policy are discussed. It is concluded that broad implementation of the precautionary principle in this country will require important changes in the conduct of environmental science and policy, as well as political mandates for government agencies and businesses to act in a precautionary manner.

Lemus-Ruiz, Blanca E: ScD (1999)
Title: Bitter sweetness: the health impart of privatization of a sugar mill in Mexico
Abstract: Mexico is an active participant in the globalization process. In addition to rapidly opening its economy to international trade and to promoting its integration into the North American Free Trade Area (NAFTA), the government aggressively proceeded to privatize many of its productive holdings. The state-owned sugar industry was one of the first to be placed in the hands of the private sector, in part because of its symbolic role in radical politics during years following the 1910 Revolution; sugar cane and mill workers played an important role in the armed struggles of the revolutionary period (1910-1917). Organized into a militant labor union, they became staunch supporters of the new government. Furthermore, in the early years of industrialization, the sugar industry was very important for the Mexican economy and the union played an active role in the political arena.> Since the privatization of the sugar mills, the sugar workers have experienced a dramatic reorganization of the work process and the industry-union relationship is being re-shaped. These changes can be observed quite clearly through a study of health and safety in the work place. This dissertation offers an analysis of the impact of the privatization on worker's health and safety. Since the economic and social changes in the work process have a direct impact on the community as a whole, the research also explores these effects.

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Barbeau, Elizabeth M.: ScD (1998)
Title: Displaced tobacco workers, public health, and tobacco policy: moving beyond jobs versus health
Abstract: Background: Efforts to reduce tobacco use in the United States are having negative effects on employment levels in the tobacco industry and positive effects on the general public's health.

Hypothesis: The central hypothesis is that the public health tobacco control movement has failed to develop policies or guiding principles regarding unemployment effects induced, in part, by successful efforts to reduce tobacco consumption in the United States. A secondary but related question is why the movement has given little opportunity for workers' voices to be heard in debates over worksite smoking policies.

Methods: A case study was conducted to characterize the nature and extent of displacement among a group of cigarette manufacturing workers in Reidsville, North Carolina. The public health tobacco control movement's consideration of unemployment effects was assessed by: 1) reviewing peer-reviewed published literature; 2) reviewing public policy resolutions adopted by key public health organizations or coalitions of public health organizations, and 3) conducting key informant interviews among several leading figures in public health and tobacco control.

Results: Until very recently the public health tobacco control movement virtually ignored the issue of unemployment. Recent attention to this issue is discussed in the context of major current events, particularly the proposed "tobacco settlement" negotiated between the tobacco industry and 40 state attorneys general in 1997.

Conclusions: The lack of attention to workers' concerns with respect to tobacco policy arises out of the public health tobacco control movement's belief in the ability of a market economy to correct unemployment and an acceptance of paternalistic approaches to tobacco control. Recommendations are made for public health to avoid alienating entire groups of the public and to build broader-based coalitions.

Most, Ivan G.: ScD (1998)
Title: Quality of the workplace organization and its relationship to employee health
Abstract: The goal of this research is to learn how organizations change when confronted with changes in government policy and economic conditions and how workplace organization and management policy affects risk and the ability to reverse risk. The case study methodology was used to explore organizational change in three companies. The case study is used to test three hypotheses:.

Workplace organization influences the success of health and safety programs: turnover at critical jobs and the transfer of cooperative programs when companies are sold become critical policy issues at the companies studied and affect the institutionalization of cooperative compliance programs.
Management commitment is necessary to successfully implement new regulatory policy: the role of communications between management and employees and the role of safety incentives in changing individual behavior were additional themes that emerged related to this original hypothesis.
Government sanctions can affect health and safety program implementation.
By studying three Maine companies that have participated in the Maine Top 200 Program, the effect this innovative regulatory policy had on the organizational behavior was assessed.
Techniques to measure organizational change were evaluated during the case study research to see if they could effectively measure company performance under a cooperative compliance program. An interview protocol was developed and used during the on-site interviews.
While this is a study of the experience of three companies that participated in a pilot regulatory process general conclusions cannot be drawn on the role of voluntary regulation in society at large. One feature of the voluntary procedure is a need to evaluate the progress of the companies in meeting certain guidelines established by the regulatory agency. How well the government evaluated the subject companies and whether this evaluation included all the important attributes of a successful program is part of this research.

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Siqueira, C. Eduardo: ScD (1998)
Title: Dependent Convergence: The Struggle for the control of petrochemical hazards in Brazil and the U.S.
Abstract: The international literature on the export or migration of hazards from developed to developing countries, has for the most part focused on the perspectives of exporting countries. Initial empirical evidence showed that Cetrel, the waste management company for the Camaari Petrochemical Complex, located in Bahia, Brazil, has developed a long-term cooperation with the Gulf Coast Waste Disposal Authority, the waste management company for the Gulf Coast area of Texas. This research adds to that literature by studying the process of importation of petrochemical hazards and controls by Cetrel from the perspective of the importers, i.e., Brazilian social actors. Three case studies were conducted to describe and analyze this process: the first is a case study of two benzene-related occupational and environmental health crises that affected the complex in the eighties; the second is a case study of the environmental policies adopted by Cetrel; the third is a case study of the environmental policies carried out by the Gulf Coast Authority. These case studies used key informant interviews and secondary sources of data to reconstruct the social history of the policies adopted in both companies. Comparative analyses of social actors and policy outcomes in Bahia and Texas show the similarities and differences between the actors and the policies adopted in each case. As a result of historical and structural developments in Bahia and Texas, Cetrel and GCA developed similar pollution control standards and technologies for protecting the environment and workers, a trend called dependent convergence. Recommendations are made for stronger international solidarity among progressive forces in developed and developing countries to promote preventive alternatives to pollution control.

Slatin, Craig: ScD (1998)
Title: Training for Action: The Political Economy of the Superfund Worker Training Program
Abstract: Background: Between 1979 - 1986 the AFL-CIO and several unions pursued a worker health and safety policy initiative addressing the emerging hazardous waste management industry. This resulted in worker protection provisions within the Superfund Amendments and Reauthorization Act of 1986. The legislation mandated a training grant program to be directed by the National Institute of Environmental Health Sciences (NIEHS), which would fund non-profit organizations to develop and deliver health and safety training for workers engaged in hazardous waste operations and emergency response. The program was named the Superfund Worker Training Program.

Research Goals and Aims: The research has two primary goals: 1) To analyze the political economy of the Superfund Worker Training Program; and, 2) To examine how the organization of industrial production and its associated social and political relations impact work environment intervention strategies. This research aimed to study: 1) The history of the above stated policy initiative; and, 2) The efforts that shaped the initial five years of the Superfund Worker Training Program.

Methods: A social and political history was developed of labor's hazardous waste worker protection initiative. An historical case study was conducted of the first five years of the Superfund Worker Training Program. Embedded case studies were conducted of two programs, one by a labor union, the Oil, Chemical, and Atomic Workers Union (OCAW), and the other by a joint labor/management training and education fund, the Laborers-Associated General Contractors. An actor/social context analysis was conducted. Results: Labor succeeded in achieving state interventions on behalf of workers' health. This victory was won as a result of the strength of the environmental movement. NIEHS has established an effective and flexible model for a worker health education intervention. The OCAW and the Laborers have used health and safety training as a strategy for organizing and mobilizing workers. Activist professionals collaborated with labor throughout this effort.

Conclusions: The SWTP is a model for worker health education interventions. The keys to labor's success were collaborations with professionals and the health and safety and environmental movements.

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Somers, Carol Ann: ScD (1997)
Title: In the eyes of the beholder: studies of workplace risk perception and social location
Abstract: This study of 2709 industrialized workers suggests that social location, health identity, and use of protective equipment are significant variables contributing to some of the variability associated with risk perceptions in the workplace. Social location remained the most important socially constructed independent variable affecting risk perception.

Given the social construction of risk found in this workplace and the literature review which supported the social construction of workplace risk, the study also lends support to a portion of the actor analysis framework of risk. The study is viewed in context of a rational paradigm that exerts a social influence on risk perception whereby workers and managers incorporate social location, health identity and the use of protective clothing within their risk perception in order to productively and effectively deal with their work life.

The conclusions focus on improving the established, but deficient, worker education programs which presume everyone holds the same perception of risk. Recommendations that encourage occupational health training professionals to broaden the scope and preparation of training sessions are given so inclusion of aggregated workers' reports of risks, health, and use or non-use of protective equipment be considered. This understanding may lead to a motivating learning environment where workers, managers, and trainers undertake an active approach to prevent and to reduce workplace injuries.

The findings support occupational health training include discussion of social location, health and personal protective equipment (PPE) in relationship to risk perception given their significance within this study.

Rosenberg, Beth J.: ScD (1994)
Title: The best laid bans: the impact of pesticide bans on workers
Abstract: Chemical bans are one way to regulate hazardous chemicals. Removing a chemical from the web of use and production has numerous ripple effects. The effects on workers from any kind of process change are frequently ignored, partly because of power relations and partly because there is no systematic method to study them. Pesticide bans are an extreme example of process changes. The case study method is used to examine