National Institute For Occupational Health Research Articles

NIOSH Hearing Loss Prevention Program for Mining.

Noise-induced hearing loss (NIHL) continues to be a pervasive problem for the nation's workforce, particularly the nation's mining personnel. As one of the leading health and safety organizations in the world, the National Institute for Occupational Health and Safety (NIOSH) in Pittsburgh maintains a Hearing Loss Prevention Program (HLPP) to conduct research to reduce NIHL loss among the nation's miners. This document provides a brief overview of this HLPP, describing some of the research techniques involved in the development of engineering noise controls, methods for the development of administrative noise controls, and some of the products available to the public to protect the nation's workers hearing.

Managing the risks of an asbestos bulk storage facility at a research institute.

The South African National Institute for Occupational Health (NIOH), formerly the Pneumoconiosis Research Unit, has previously milled about 544 kg of anthophyllite, crocidolite, amosite and chrysotile asbestos fibre materials. This endeavour came about in an attempt to address a recommendation, made by the International Union Against Cancer (UICC), to make asbestos standard reference samples available for research. Some of these reference samples, as well as the bulk, unprocessed materials are still within the care of the NIOH and can be obtained for the purpose of Public Health research under strict terms and conditions. Considering the hazardous nature of asbestos and regulated prohibitions imposed on this mineral, the NIOH asbestos storage facility is being subjected to various occupational and environmental control measures to ensure that any potential fibre release, and subsequent risk of exposure, are prevented.

Electrospun Polystyrene and Acid-Treated Cellulose Nanocrystals with Intense Pulsed Light Treatment for N95-Equivalent Filters

The coronavirus (SARS-CoV-2) has prompted a global need and shortage of face masks and respirators. Electrospinning of polystyrene and cellulose nanocrystals (CNCs) is used to fabricate filter materials exceeding N95 standards set by the National Institute for Occupational Health and Safety. The desired filtration efficiency and pressure drop are achieved from filters with varying amounts of input material. The water contact angle, fiber morphology, and surface potential are reported to explain the enhancements in filtration performance after the addition of CNCs or application of intense pulsed light (IPL). The improved durability in the form of increased mechanical properties and lower pressure drop after testing are also examined. The samples exhibited filtration efficiencies greater than 99% and an initial pressure drop as low as 231 Pa. The combination of CNCs and IPL shows the potential to use thinner membranes with less material to achieve comparable filtration performance, which may result in lower manufacturing costs. © 2021 American Chemical Society.

Visualization analysis of relevant literature on occupational health risk assessment from 2010 to 2019

Objective: To understand the research status of occupational health risk assessment in recent ten years. Methods: In April 2020, the literatures related to occupational health risk assessment published by CNKI and Web of Science core collection (WoSCC) databases from 2010 to 2019 were searched, and Excel 2016 software was used to organize the literature, CiteSpace 5.6.R2 software was used for visual analysis. Results: A total of 58 Chinese literatures and 407 English literatures were included. The authors of the high frequency posts were Zhang Meibian, and Alessandro Marinaccio, and the publishing institutions were mainly the National Institute for Occupational Health and Poison Control of Chinese Center for Disease Control and Prevention and Finnish Institute Occupational Health. The Chinese journal with the most articles was Chinese Journal of Industrial Hygiene and Occupational Diseases, and the English journal was Safety Science. Chinese high-frequency keywords mainly included risk assessment, occupational health, occupational exposure. English high-frequency keywords mainly included occupational health, risk, risk factor. The prominent words in Chinese literature were occupational health, coal dust, occupational hazards, occupational health and occupational disease hazards; Risk assessment, worker, exposure, heart disease, cardiovascular disease and so on were prominent words in English literature. Conclusion: The main research keywords in the field of occupational health risk assessment at home and abroad focus on occupational health and risk assessment, but the research direction and focus are slightly different.

The Effect on Fit of Multiple Consecutive Donning and Doffing of N95 Filtering Facepiece Respirators.

N95 filtering facepiece respirators (FFRs) are widely used in healthcare to reduce transmission of airborne infectious diseases. These respirators are generally described as single use or limited reuse devices, but cost and operational issues mean that they may be donned and doffed multiple times. There is scant research on the effect of this practice on adequacy of fit. The purpose of this study was to measure the effect on respirator fit of multiple donning and doffing of N95 FFRs. This was an experiment in which 16 women and 9 men employed by the National Institute for Occupational Health (NIOH), Johannesburg, donned their same N95 FFR six times. All 25 were trained in the correct wearing of the devices before the experiment. Four models of respirators were used: the six who did not use respirators at work (novice subjects) were issued a 3M 1860 FFR and the others used their currently supplied one. During the experiment subjects donned their respirators under the supervision of the tester. Quantitative fit testing was done in the NIOH Occupational Hygiene laboratory after each donning according to the OSHA-Accepted Fit Test Protocol using the TSI PortaCount Pro+ Model 8038 Respirator Fit Tester. During the test, fit was measured after each of seven exercises and then an overall fit factor was computed. Only individuals who achieved an initial overall fit factor of ≥100 were allowed to continue participation in the study. Median overall fit factors were calculated for the 25 subjects for each donning and changes across them was examined using Wilcoxon rank sum tests. Men and women and frequent and infrequent users were compared across the six tests. Infrequent use was defined as subjects who wore respirators ≤ once per week, and novice subjects. Two subjects (8%) had an overall fit factor <100 at fit Test 2, 6 (24%) at Test 3, and 8 (32%) at Tests 4, 5, and 6. Thirteen respirator users (52%) achieved ≥100 throughout the fit testing, so 12 had at least one failure at either Tests 2-6. Five of the 12 subjects with at least one failure showed persistent failures on all subsequent donnings. Six subjects out of 12 (50%) who failed a fit test achieved an overall fit factor >100 at a subsequent test. There was a significant difference between the median first and sixth overall fit factors (195 versus 150; P = 0.0271), but not between the second and sixth (161 versus 150; P = 0.3584). Men and women had similar overall fit factors, but infrequent users had larger average overall fit factors than frequent users after all six donnings. Forty-eight percent of study subjects failed at least one fit test after re-donning an N95 FFR. The fit test data suggest that donning practices probably accounted for the fit test failures. The 50% of subjects who produced overall fit factors ≥100 after a test of <100 supports this contention.

Injuries and Exposure to Time Lobstering in Northeast US Inshore Lobster Fleet

ABSTRACTObjectives: The study objective was to estimate a denominator of exposure to inshore lobstering in Full-Time Equivalents (FTEs), to count incident injury data from a sample cohort of this population, to use this count to calculate rates for incident injuries, and to use official counts of fatalities to estimate a fatality rate.Methods: Captains were randomly selected from those licensed to fish in Maine and Massachusetts. Data on work exposure and injuries that occurred on the boat were collected using a survey that was administered once per season via phone or face-to-face interview with the captain. Data included self-reports of the number of weeks worked during the season, average crew size, number of trips per week, and average trip length in hours. In addition, this survey captured relevant information (body segment affected, type of injury, and whether treatment was received) on all acute injuries occurring during the season. Only data on acute injuries were collected, and defined as having newly occurred within the last 3 months. Counts of fatalities were obtained from an official surveillance database at the National Institute for Occupational Health and Safety.Results: The total occupational exposure reported for the cohort was over 2 million man-hours over 4 years, resulting in an average annual FTE of 5,847. The fatality rate averaged over 4 years was 21/100,000 FTE. The incidence rates for all injuries (51.0/100 FTE) and injuries receiving treatment (17.5/100 FTE) were much higher than those reported in other studies of fishing that used US Coast Guard data. Lobstermen presented with all categories of injuries, sprains being the most frequent (7.8/100 FTE) and amputations the least (0.2/100 FTE). Wrist/hand injuries on the right side occurred most frequently of all body locations (3.6/100 FTE).Conclusion: Non-fatal injuries occur at high rates in lobstering. The impact of interventions aimed at exposure to risk for sprains and cuts has potential to affect the most lobstermen. Fatality rate appears to have been unchanging since the year 2000.

Environmental and biological monitoring in the workplace: A 10-year South African retrospective analysis

This report is an overview of requests for biological and environmental monitoring of hazardous chemicals, submitted to the National Institute for Occupational Health, Analytical Services Laboratory for testing from the years 2005 to 2015. The report discusses the nature of tests requested and implications for workers' health and environment, as well as potential impact of the uncertainties associated with monitoring of hazardous chemicals. This is a retrospective, descriptive, qualitative and quantitative audit of all samples received and tests performed retrieved from records of analysis by the laboratory. The study sample consisted of 44,221 samples. The report indicates that throughout the interrogation period the demand for biological monitoring was higher than that for environmental monitoring, with more requests for toxic metals than organic pollutants. Toxic metal testing was highest for mercury, followed by manganese, lead, aluminium and arsenic. The highest number of tests for organic pollutants was conducted for pesticides followed by toluene and xylene. The study has also revealed that the scope of tests requested is rather narrow and does not reflect the broad spectrum of South Africa's industrial diversity. Having identified possible reasons for underutilization, a number of reforms that could enhance the laboratory's performance have been addressed.

Assessment and control of exposures to polymeric methylene diphenyl diisocyanate (pMDI) in spray polyurethane foam applicators.

In this work we characterize personal inhalation and dermal exposures to diphenyl methane diisocyanate (MDI) and other species in polymeric MDI (pMDI) formulations during spray polyurethane foam (SPF) insulation at 14 sites in New England. We further assess the adequacy of current workplace practices and exposure controls via comparative urinary biomonitoring of the corresponding methylene diphenyl diamine (MDA) pre- and post-shift. MDI and pMDI are potent dermal and respiratory sensitizers and asthmagens, strong irritants of the skin, eyes, and the respiratory tract, and may cause skin burns. This study is the first comprehensive report to-date on the work practices, inhalation and dermal exposures to isocyanates and effectiveness of existing controls during SPF applications. Breathing zone exposures to 4,4' MDI (n = 31; 24 sprayers, 7 helpers) ranged from 0.9 to 123.0 μg/m3 and had a geometric mean (GM) of 13.8 μg/m3 and geometric standard deviation (GSD) of 4.8. Stationary near field area samples (n = 15) were higher than personal exposures: GM, 40.9 (GSD, 3.9) μg/m3, range 1.4-240.8 μg/m3. Sixteen percent of personal air samples and 35% of area samples exceeded the National Institute for Occupational Health and Safety's (NIOSH) full shift recommended exposure limit (REL) of 50 μg/m3, assuming zero exposure for the unsampled time. 4,4' MDI load on the glove dosimeters had a GM of 11.4 (GSD 2.9) μg/glove pair/min, suggesting high potential for dermal exposures. Urinary MDA had a GM of 0.7 (GSD, 3.0) μmol MDA/mol creatinine (range, nd-14.5 μmol MDA/mol creatinine). Twenty-five % of urine samples exceeded the Health and Safety Executive (HSE) biological monitoring guidance value (BMGV) of 1 μmol MDA/mol creatinine. We further report on field observations regarding current exposure controls, discuss implications of these findings and opportunities for improving work practices to prevent isocyanate exposures during SPF insulation.

Environmental and biological monitoring in the workplace: A 10-year South African retrospective analysis

This report is an overview of requests for biological and environmental monitoring of hazardous chemicals, submitted to the National Institute for Occupational Health, Analytical Services Laboratory for testing from the years 2005 to 2015. The report discusses the nature of tests requested and implications for workers’ health and environment, as well as potential impact of the uncertainties associated with monitoring of hazardous chemicals. This is a retrospective, descriptive, qualitative and quantitative audit of all samples received and tests performed retrieved from records of analysis by the laboratory. The study sample consisted of 44,221 samples. The report indicates that throughout the interrogation period the demand for biological monitoring was higher than that for environmental monitoring, with more requests for toxic metals than organic pollutants. Toxic metal testing was highest for mercury, followed by manganese, lead, aluminium and arsenic. The highest number of tests for organic pollutants was conducted for pesticides followed by toluene and xylene. The study has also revealed that the scope of tests requested is rather narrow and does not reflect the broad spectrum of South Africa’s industrial diversity. Having identified possible reasons for underutilization, a number of reforms that could enhance the laboratory’s performance have been addressed.

Environmental and biological monitoring in the workplace: A 10-year South African retrospective analysis

This report is an overview of requests for biological and environmental monitoring of hazardous chemicals, submitted to the National Institute for Occupational Health, Analytical Services Laboratory for testing from the years 2005 to 2015. The report discusses the nature of tests requested and implications for workers’ health and environment, as well as potential impact of the uncertainties associated with monitoring of hazardous chemicals. This is a retrospective, descriptive, qualitative and quantitative audit of all samples received and tests performed retrieved from records of analysis by the laboratory. The study sample consisted of 44,221 samples. The report indicates that throughout the interrogation period the demand for biological monitoring was higher than that for environmental monitoring, with more requests for toxic metals than organic pollutants. Toxic metal testing was highest for mercury, followed by manganese, lead, aluminium and arsenic. The highest number of tests for organic pollutants was conducted for pesticides followed by toluene and xylene. The study has also revealed that the scope of tests requested is rather narrow and does not reflect the broad spectrum of South Africa’s industrial diversity. Having identified possible reasons for underutilization, a number of reforms that could enhance the laboratory’s performance have been addressed.

Direct-on-Filter α-Quartz Estimation in Respirable Coal Mine Dust Using Transmission Fourier Transform Infrared Spectrometry and Partial Least Squares Regression.

In order to help reduce silicosis in miners, the National Institute for Occupational Health and Safety (NIOSH) is developing field-portable methods for measuring airborne respirable crystalline silica (RCS), specifically the polymorph α-quartz, in mine dusts. In this study we demonstrate the feasibility of end-of-shift measurement of α-quartz using a direct-on-filter (DoF) method to analyze coal mine dust samples deposited onto polyvinyl chloride filters. The DoF method is potentially amenable for on-site analyses, but deviates from the current regulatory determination of RCS for coal mines by eliminating two sample preparation steps: ashing the sampling filter and redepositing the ash prior to quantification by Fourier transform infrared (FT-IR) spectrometry. In this study, the FT-IR spectra of 66 coal dust samples from active mines were used, and the RCS was quantified by using: (1) an ordinary least squares (OLS) calibration approach that utilizes standard silica material as done in the Mine Safety and Health Administration's P7 method; and (2) a partial least squares (PLS) regression approach. Both were capable of accounting for kaolinite, which can confound the IR analysis of silica. The OLS method utilized analytical standards for silica calibration and kaolin correction, resulting in a good linear correlation with P7 results and minimal bias but with the accuracy limited by the presence of kaolinite. The PLS approach also produced predictions well-correlated to the P7 method, as well as better accuracy in RCS prediction, and no bias due to variable kaolinite mass. Besides decreased sensitivity to mineral or substrate confounders, PLS has the advantage that the analyst is not required to correct for the presence of kaolinite or background interferences related to the substrate, making the method potentially viable for automated RCS prediction in the field. This study demonstrated the efficacy of FT-IR transmission spectrometry for silica determination in coal mine dusts, using both OLS and PLS analyses, when kaolinite was present.

Notes from the Field: Respiratory Symptoms and Skin Irritation Among Hospital Workers Using a New Disinfection Product - Pennsylvania, 2015.

In March 2014, a new disinfection product, consisting of hydrogen peroxide, peroxyacetic acid, and acetic acid, was introduced at a Pennsylvania hospital to aid in the control of health care-associated infections. The product is an Environmental Protection Agency-registered non-bleach sporicide advertised as a one-step cleaner, disinfectant, and deodorizer. According to the manufacturer's safety data sheet, the product requires no personal protective equipment when it is diluted with water by an automated dispenser before use. On January 30, 2015, CDC's National Institute for Occupational Health (NIOSH) received a confidential employee request to conduct a health hazard evaluation at the hospital. The request cited concerns about exposure of hospital environmental services staff members to the product and reported symptoms among persons who had used the product that included eye and nasal problems, asthma-like symptoms, shortness of breath, skin problems, wheeze, chest tightness, and cough.

38 years of autopsy findings in South African mine workers.

South African miners have a statutory right to autopsies for occupational lung disease compensation. These autopsies also provide information for research and surveillance. Cardio-respiratory organs are removed where miners die and are examined at the National Institute for Occupational Health. We extracted data from the PATHAUT database and described key demographic, exposure and disease trends (1975-2013). Of 109,101 autopsies, 72,348 (66.3%) were black, and 34,794 (31.9%) were white miners. Autopsies declined from over 3,000 (1975-1998) to 1,118 in 2013. Most were gold miners (74.0%). 78.6% black and 13.2% white miners died while in employment. Overall proportions of silicosis and pulmonary tuberculosis were 12.0% and 13.0% in black, and 20.5% and 2.4% in white miners, respectively. Disease increased over time. High levels of disease persist. Black ex-miners are underrepresented, indicating a need for strategies to improve awareness and provision of autopsy facilities in labor-sending areas.

The relationship of positive work environments and workplace injury

With estimates of a 51% growth in the number of nursing assistants needed by 2016, there is a critical need to examine workplace factors that negatively contribute to the recruitment and retention of nursing assistants. Studies have shown that high demands, physical stress, and chronic workforce shortages contribute to a working environment that fosters one of the highest workforce injury rates in the United States. The aim of this study was to explore the relationship between nursing assistant injury rates and key outcomes, such as job satisfaction and turnover intent, while exploring workplace environment factors, such as injury prevention training, supervisor support, and employee engagement, that can decrease the rates of workplace injury. Data from the 2004 National Nursing Assistant Survey were used to examine the negative effects of workplace injury on nursing assistants and the workplace environment factors that are related to the rate of worker injury. Nursing assistants who experience job-related injuries have lower levels of job satisfaction, increased turnover intentions, and are less likely to recommend their facility as a place to work or seek care services. It was also found that nursing assistant injury rates are related to employee ratings of injury prevention training, supervisor support, and employee engagement. NAs with multiple injuries (>2) were 1.3-1.6 times more likely to report being injured at work than NAs who had not been injured when supervisor support, employee engagement, and training ratings were low. Evidence that health care organizations can use to better understand how workplace injuries occur and insight into ways to reduce the current staggering rate of on-the-job injuries occurring in health care workplaces were offered in this study. The findings also offer empirical support for an extension of the National Institute for Occupational Health and Safety/National Occupational Research Agenda Work Organization Framework for Occupational Illness and Injury.

Silicosis at autopsy in platinum mine workers

South Africa is the largest producer of platinum group metals in the world. Platinum is found in the Bushveld Complex in the north-east of the country. This volcanic intrusion contains many other minerals, including crystalline silica. Little is known about the health risks in the platinum mining industry. To explore the potential for platinum mine workers to develop silicosis. Autopsies are performed at the National Institute for Occupational Health, for compensation purposes. Platinum mine workers, who had worked for more than a year and had silicosis and/or fibrotic nodules in the lymph nodes, were identified from the autopsy database. An exhaustive search of other available data sources was undertaken to exclude exposure to silica dust in the gold mining industry. Eighty-five of 3863 (2.2%) platinum mine workers employed for more than a year had silicosis at autopsy; an additional 490 (12.7%) had fibrotic nodules in the lymph nodes. After reviewing all data sources, five mine workers with silicosis and 25 with fibrotic nodules in the lymph nodes fulfilled the study inclusion criteria. This case series supports the suggestion that there is a risk of silica exposure in platinum mine workers, a hypothesis supported by the few silica dust measurements taken in the platinum mines. The mining companies should be cognisant of this risk. The recording of comprehensive work histories and the routine measurement of silica dust levels should be enforced to enable risk of disease to be quantified in future studies.

Determinants of exposure to 2-butoxyethanol from cleaning tasks: a quasi-experimental study.

The quantitative assessment of airborne cleaning exposures requires numerous measurement methods, which are costly and difficult to apply in the workplace. Exposure determinants can be used to predict exposures but have yet to be investigated for cleaning activities. We identified determinants of exposure to 2-butoxyethanol (2-BE), a known respiratory irritant and suspected human carcinogen, commonly found in cleaning products. In addition, we investigated whether 2-BE exposures can be predicted from exposure determinants and total volatile organic compounds (TVOCs) measured with direct reading methods, which are easier to apply in field investigations. Exposure determinants were studied in a quasi-experimental study design. Cleaning tasks were performed similarly as in the workplace, but potential factors that can impact exposures were controlled. Simultaneously for each task, we measured concentrations of (1) 2-BE according to the National Institute for Occupational Health and Safety 1430 method and (2) TVOC with photoionization detectors (PIDs). Simple and multiple linear regression analyses were performed to identify 2-BE exposure determinants and to develop exposure prediction models. Significant determinants from univariate analyses consisted of product type, tasks performed, room volume, and ventilation. The best-fit multivariable model was the one comprised of product type, tasks performed, 2-BE product concentration, room volume, and ventilation (R(2) = 77%). We found a strong correlation between the 2-BE and the TVOC concentrations recorded by the PID instruments. A multivariable model with TVOC explained a significant portion of the 2-BE concentrations (R(2) = 72%) when product type and room ventilation were included in the model. Our results suggest that quantitative exposure assessment for an epidemiologic investigation of cleaning health effects may be feasible even without performing integrated sampling and analytic measurements.

Classifying the risk of work related low back disorders due to manual material handling tasks

Work related low back disorders (LBDs) due to manual lifting tasks (MLTs) have long been recognized as one of the main occupational disabling injury that affects the quality of life of the industrial working population in the U.S. There have been a number of intensive research efforts devoted to understanding the phenomena of LBDs and building classification models that could effectively distinguish between high risk and low risk MLTs that contribute to LBDs. As of today, however, such models and the occupational exposure limits of different risk factors causing LBDs as well as the guidelines preventing them have not yet been fully proposed. One of the first efforts to comprehend the nature and phenomenon of LBDs was undertaken by Marras et al. (1993). They created a seminal data set and used it to build logistic regression (LR) models to identify significant variables and classify MLTs into high risk and low risk with respect to LBDs. Since then a number of studies have used the same data set to build and test various classifiers to detect the likelihood of LBDs due to manual material handling jobs. This paper summarizes and critiques the previous studies. It also employs this data set to build and test seven classification models, two of which have not been applied in this context yet. The parameters of the models have been calibrated for the best performance, and the models were constructed and validated on the full set and the reduced set of features. Though the performances of our best models are better than those reported in National Institute for Occupational Health and Safety (NIOHS) Guides and two of our previous studies, they are generally less optimistic than those reported in several other studies; this paper proposes a systematic and more reliable approach to creating and validating classifiers to distinguish between low and high risk MLTs that contribute to LBDs.

Research capacity development in South African manganese mines to bridge exposure and neuropathologic outcomes

Manganese (Mn) is a common occupational exposure worldwide. Recent studies indicate clinical and imaging evidence of neurotoxicity in chronically exposed workers. The pathologic significance of these findings is unclear. South Africa produces over 80% of the world's Mn from mines from a desert region in the Northern Cape Province. An autopsy program at the National Institute for Occupational Health (NIOH) in South Africa has provided compensation to families for mining-related lung diseases for almost 100 years. Building on this, we implemented a brain autopsy program to investigate the feasibility of obtaining brains from South African Mn miners and non-exposed reference miners to investigate neuropathologic consequences of chronic Mn exposure. Employing an experienced occupational health nurse, we identified deceased miners within 100 square km of the Mn mines. The nurse was notified of any Mn (case) or other (reference) miner or ex-miner death by local medical practitioners, occupational health and mine physicians, and community members, and families were approached for consent to remove the brains in addition to the cardio-respiratory organs. Families of deceased miners who had an autopsy at the NIOH in Johannesburg were also approached. To confirm exposure in Mn miners, mean pallidal indices were compared between Mn miners and non-exposed reference miners. Sixty-eight potential brain donors were identified; we obtained consent from the families to remove 51 (75%). The mean autopsy interval was seven days. With optimized fixation methods, the tissue quality of the brains for gross and regular microscopic examination was excellent. Ex vivo MRI demonstrated increased pallidal index in Mn miners compared to reference miners. We conclude that obtaining brain tissue from deceased miners in South Africa is highly successful with only a modest investment in local infrastructure. Tissue quality was excellent and should be ideal to investigate the neuropathologic consequences of chronic occupational Mn exposure.

Carpal tunnel syndrome and its relationship to occupation: a meta-analysis

To examine the association between work place exposure and CTS by meta-analysis, including analyses with respect to exposure to hand force, repetition, vibration and wrist posture. All relevant peer-reviewed articles published between January 1980 and December 2009 were identified by a systematic search using the MEDLINE, CINAHL and PubMed databases. Papers were critiqued independently by two researchers and the relevant exposure information was extracted. Using the raw data of exposed and unexposed cases, a cumulative effect of specific exposure risks were calculated for hand force, repetition, a combination of force and repetition, vibration and wrist posture using the statistical program, Stata version 11 (StataCorp, College Station, TX, USA). Heterogeneity, meta-regression, publication bias and subgroup sensitivity analyses were performed. Thirty-seven studies from English-language literature met the inclusion criteria. Using National Institute for Occupational Health and Safety criteria for case definition, a significant positive association between CTS and hand force, repetition, use of vibratory tools and wrist posture was observed with approximate doubling of risk for all exposures. Significant heterogeneity among studies was observed for most exposures and metaregression analyses identified CTS case definition, study design, country and risk of bias score to be the significant determinants. When a more conservative definition of CTS was employed to include nerve conduction abnormality with symptoms and/or signs, risk factors significantly associated with an increased risk of CTS among exposed workers were: vibration [odds ratio (OR) 5.40; 95% CI 3.14, 9.31], hand force (OR 4.23; 95% CI 1.53, 11.68) and repetition (OR 2.26; 95% CI 1.73, 2.94). There was a non-significant trend for the association between CTS and combined exposure to both force and repetition (OR 1.85; 95% CI 0.99, 3.45) and wrist posture (OR 4.73; 95% CI 0.42, 53.32). Occupational exposure to excess vibration, increased hand force and repetition increase the risk of developing CTS. Workplace strategies to avoid overexposure to these risk factors should be implemented.

Partnerships for Environmental and Occupational Justice: Contributions to Research, Capacity and Public Health

In 1994, the National Institute of Environmental Health Sciences (NIEHS) initiated a program to address communication gaps between community residents, researchers and health care providers in the context of disproportionate environmental exposures. Over 13 years, together with the Environmental Protection Agency and National Institute for Occupational Health and Safety, NIEHS funded 54 environmental justice projects. Here we examine the methods used and outcomes produced based on data gathered from summaries submitted for annual grantees' meetings. Data highlight how projects fulfilled program objectives of improving community awareness and capacity and the positive public health and public policy outcomes achieved. Our findings underscore the importance of community participation in developing effective, culturally sensitive interventions and emphasize the importance of systematic program planning and evaluation.