Search

Objective: Retinal detachment (RD) has been associated with exposure to heavy lifting. Many occupations within the construction industry are likely to involve lifting tasks. We investigated the association between occupational heavy lifting and rhegmatogenous RD in a retrospective cohort study of Swedish construction workers., Methods: We studied Swedish construction workers who participated in an industry-wide health and safety program from 1971 to 1993. Individual occupation codes were linked to a job exposure matrix, assigning intensity of exposure to heavy lifting to each worker. The Swedish National Patient Register was used to identify cases of RD that occurred during follow-up through the end of 2012. We used Poisson regression modeling to calculate incidence rates of RD associated with heavy lifting, age and other covariates. A subcohort of those age ≤25 years at enrollment was studied to reduce bias from missing exposure information from work prior to enrollment., Results: Of 256 241 construction workers, 17% were classified with high exposure to heavy lifting in their occupation. Within the cohort, 1588 cases of RD were identified. Average exposure intensity of heavy lifting was not associated with risk of RD. However, RD risk increased with increasing cumulative exposure to heavy lifting, both in the full cohort and subcohort of those who were ≤25 years old at entry into the construction-worker cohort., Conclusion: Construction workers' risk of RD appeared to increase with time spent exposed to heavy lifting.

Objectives: In the USA, deaths from poisonings (especially opioids), suicides, and alcoholic liver disease, collectively referred to as 'deaths of despair', have been increasing rapidly over the past two decades. The risk of deaths from these causes is known to be higher among certain occupations. It may be that specific exposures and experiences of workers in these occupations explain these differences in risk. This study sought to determine whether differences in the risk of deaths of despair were associated with rate of occupational injuries and illnesses, job insecurity, and temporal changes in employment in non-standard work arrangements., Methods: Usual occupation information was collected from death certificates of Massachusetts residents aged 16-64 with relevant causes of death between 2005 and 2015. These data were combined with occupation-level data about occupational injuries and illnesses, job insecurity, and non-standard work arrangements. We calculated occupation-specific mortality rates for deaths of despair, categorized by occupational injury and illnesses rates and job insecurity. We calculated trends in mortality according to changes in non-standard work arrangements., Results: Workers in occupations with higher injury and illnesses rates and more job insecurity had higher rates of deaths of despair, especially opioid-related deaths. Rates of deaths of despair increased most rapidly for occupations with increasing prevalence of workers employed in non-standard work arrangements., Conclusions: The findings suggest occupational factors that may contribute to the risk of deaths of despair. Future studies should examine these factors with individual-level data. In the meantime, efforts should be made to address these factors, which also represent known or suspected hazards for other adverse health outcomes., (© The Author(s) 2021. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

Background: Exposure to COVID-19 is more likely among certain occupations compared with others. This descriptive study seeks to explore occupational differences in mortality due to COVID-19 among workers in Massachusetts., Methods: Death certificates of those who died from COVID-19 in Massachusetts between March 1 and July 31, 2020 were collected. Occupational information was coded and age-adjusted mortality rates were calculated according to occupation., Results: There were 555 deaths among MA residents of age 16-64, with usable occupation information, resulting in an age-adjusted mortality rate of 16.4 per 100,000 workers. Workers in 11 occupational groups including healthcare support and transportation and material moving had mortality rates higher than that for workers overall. Hispanic and Black workers had age-adjusted mortality rates more than four times higher than that for White workers overall and also had higher rates than Whites within high-risk occupation groups., Conclusion: Efforts should be made to protect workers in high-risk occupations identified in this report from COVID-19 exposure., (© 2021 Wiley Periodicals LLC.)

Objectives: Assess the impact of summer heat exposure (June-September) on residential construction workers in Al-Ahsa, Saudi Arabia by evaluating (i) heart rate (HR) responses, hydration status, and physical workload among workers in indoor and outdoor construction settings, (ii) factors related to physiological responses to work in hot conditions, and (iii) how well wet-bulb globe temperature-based occupational exposure limits (WBGTOELs) predict measures of heat strain., Methods: Twenty-three construction workers (plasterers, tilers, and laborers) contributed 260 person-days of monitoring. Workload energy expenditure, HR, fluid intake, and pre- and postshift urine specific gravity (USG) were measured. Indoor and outdoor heat exposures (WBGT) were measured continuously and a WBGTOEL was calculated. The effects of heat exposure and workload on heart rate reserve (HRR), a measure of cardiovascular strain, were examined with linear mixed models. A metric called 'heat stress exceedance' (HSE) was constructed to summarize whether the environmental heat exposure (WBGT) exceeded the heat stress exposure limit (WBGTOEL). The sensitivity and specificity of the HSE as a predictor of cardiovascular strain (HRR ≥30%) were determined., Results: The WBGTOEL was exceeded frequently, on 63 person-days indoors (44%) and 91(78%) outdoors. High-risk HRR occurred on 26 and 36 person-days indoors and outdoors, respectively. The HSE metric showed higher sensitivity for HRR ≥30% outdoors (89%) than indoors (58%) and greater specificity indoors (59%) than outdoors (27%). Workload intensity was generally moderate, with light intensity work more common outdoors. The ability to self-pace work was associated with a lower frequency of HRR ≥30%. USG concentrations indicated that workers began and ended their shifts dehydrated (USG ≥1.020)., Conclusions: Construction work where WBGTOEL is commonly exceeded poses health risks. The ability of workers to self-pace may help reduce risks., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

Saudi Arabia (SA) is one of the hottest countries in the world. This study was conducted to assess the impact of summer heat stress in Southeastern SA on short-term kidney injury (KI) among building construction workers and to identify relevant risk factors. Measurements of urinary albumin-creatinine ratio (ACR), height, weight, hydration, symptoms, daily work and behavioral factors were collected in June and September of 2016 from a cohort of construction workers ( n = 65) in Al-Ahsa Province, SA. KI was defined as ACR ≥30 mg/g. Multivariate linear regression analysis was used to assess factors related to cross-summer changes in ACR. A significant increase in ACR occurred among most workers over the study period; incidence of KI was 18%. Risk factors associated with an increased ACR included dehydration, short sleep, and obesity. The findings suggest that exposure to summer heat may lead to the development of KI among construction workers in this region. Adequate hydration and promotion of healthy habits among workers may help reduce the risk of KI. A reduction in work hours may be the most effective intervention because this action can reduce heat exposure and improve sleep quality., Competing Interests: The authors declare no conflicts of interest. The provision of financial support does not in any way infer endorsement of the research findings by either agency. The manuscript’s contents, including any opinions and/or conclusions expressed, belong solely to the authors.

Objective: Violence from care recipients and family members, including both verbal and physical abuse, is a serious occupational hazard for healthcare and social assistance workers. Most workplace violence studies in this sector focus on hospitals and other institutional settings. This study examined verbal abuse in a large home care (HC) aide population and evaluated risk factors., Methods: We used questionnaire survey data collected as part of a larger mixed methods study of a range of working conditions among HC aides. This paper focuses on survey responses of HC aides (n=954) who reported on verbal abuse from non-family clients and their family members. Risk factors were identified in univariate and multivariable analyses., Results: Twenty-two per cent (n=206) of aides reported at least one incident of verbal abuse in the 12 months before the survey. Three factors were found to be important in multivariable models: clients with dementia (relative risk (RR) 1.38, 95% CI 1.07 to 1.78), homes with too little space for the aide to work (RR 1.52, 95% CI 1.17 to 1.97) and predictable work hours (RR 0.74, 95% CI 0.58 to 0.94); two additional factors were associated with verbal abuse, although not as strongly: having clients with limited mobility (RR 1.35, 95% CI 0.94 to 1.93) and an unclear plan for care delivery (RR 1.27, 95% CI 0.95 to 1.69). Aides reporting verbal abuse were 11 times as likely to also report physical abuse (RR 11.53; 95% CI 6.84 to 19.45)., Conclusions: Verbal abuse is common among HC aides. These findings suggest specific changes in work organisation and training that may help reduce verbal abuse., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: Excessive heat exposure poses significant risks to workers in hot climates. This study assessed the intensity and duration of heat stress exposure among workers performing residential construction in southeastern Saudi Arabia (SA) during the summer, June-September 2016. Objectives were to: identify work factors related to heat stress exposure; measure environmental heat exposure at the construction sites; assess the heat stress risk among workers using the wet bulb globe temperature (WBGT) index; and determine if temperature-humidity indices can be appropriate alternatives to WBGT for managing heat stress risk at the construction sites., Methods: Worksite walkthrough surveys and environmental monitoring were performed, indoors and outdoors, at 10 construction sites in Al-Ahsa Province. A heat stress exposure assessment was conducted according to the American Conference of Governmental Industrial Hygienists (ACGIH®) guidelines, which uses the WBGT index. WBGT measurements from two instruments were compared. Alternative heat stress indices were compared to the WBGT: the heat index (HI) and humidex (HD) index., Results: Construction workers were exposed to excessive heat stress, indoors and outdoors over a large part of the work day. Complying with a midday outdoor work ban (12-3 p.m.) was not effective in reducing heat stress risk. The highest intensity of exposure was outdoors from 9 a.m. to 12 p.m.; a period identified with the highest hourly mean WBGT values (31-33°C) and the least allowable working time according to ACGIH® guidelines. Comparison of the alternative indices showed that the HI is more reliable than the HD as a surrogate for the WBGT index in the climate studied., Conclusion: The extreme heat exposure represents a serious risk. The severity of heat stress and its impact are projected to increase due to climate change, emphasizing the need for immediate improvement of the current required protective measures and the development of occupational heat stress exposure guidelines in SA., (© The Author(s) 2019. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

Background: Irritable bowel syndrome (IBS) is a stress-related disease linked to psychosocial factors, though knowledge about its occupational psychosocial aspects is scarce., Objective: A cross-sectional study of the prevalence of IBS and its association with occupational psychosocial factors in Chilean workers was conducted., Methods: IBS prevalence, using the IBS-Rome IV criteria, in the working population was estimated using data from the National Health Survey of 2009. Data on occupational psychosocial aspects were drawn from the Chilean Survey of Employment, Health, and Work of 2009, and allocated to individual survey participants at the occupation-region level. Data on family and community stressors were available at the individual level. Prevalence ratios (PR) for IBS were computed using generalized linear mixed models to account for variability at the group level., Results: The IBS prevalence in the overall working population (weighted n = 5 435 253) was 18.4%, but varied substantially by industry sector. Compared with 'professionals' (IBS prevalence = 7.3%), jobs with high prevalence of IBS included 'health and social work activities' [PR = 4.9; 95% confidence interval (CI) = 1.4-16.7], 'household employment' (PR = 4.8; 95% CI = 1.5-15.9), and 'manufacturing' (PR = 3.5; 95% CI = 1.0-11.8). With Karasek Job Demand Control scores assigned to occupations within regions, high job demand doubled the prevalence of IBS (PR = 2.0; 95% CI = 1.4-2.9), whereas high-skill discretion was associated with lower prevalence of IBS (PR = 0.6; 95% CI = 0.4-0.8). There was also evidence that these two factors were not independent; high-skill discretion appeared to buffer the effect of high job demand on IBS prevalence (P < 0.001)., Conclusions: Occupational factors were associated with IBS prevalence, showing effects as important as those for non-occupational stresses such as civic insecurity or having health problems. High job skill discretion appeared to reduce the prevalence of IBS in the presence of high job demands. Given its high overall prevalence and poorly understood risk factors, further research on occupational psychosocial factors of IBS is warranted., (© The Author(s) 2019. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

Purpose: We conducted external comparisons for the prevalence of asthma, hypertension, diabetes, and cancer among World Trade Center (WTC) general responders using the National Health Interview Survey (NHIS) as the reference, along with internal comparisons for the incidence of asthma., Methods: Standardized Morbidity Ratios (SMRs) were calculated for the prevalence of the health conditions, and risk ratios (RRs) for asthma incidence., Results: Relative to the NHIS, asthma prevalence was in excess in responders over the study years (age-adjusted SMRs = 1.3-2.8). Hypertension prevalence began to exceed expected from 2006 while diabetes was lower than expected. An upward trend towards excess cancer prevalence was observed. Internal comparisons showed elevated asthma incidence among protective service and utility workers compared to construction workers; while those who arrived at the WTC site in the morning of 9/11 had a lower asthma risk than those who arrived in the afternoon., Conclusions: The use of NHIS data as a reference population demonstrates and reconfirms several important patterns of excess risk in WTC responders. External comparisons are an alternative for disaster cohorts without an established comparison group., (© 2018 Wiley Periodicals, Inc.)

Objectives: To investigate the association between occupational lifting and the risk of rhegmatogenous retinal detachment (RRD) using data from a large population of men., Methods: We used data from a national cohort of 49 321 Swedish men conscripted for compulsory military service in 1969-1970. We collected information on surgically treated RRD from the National Patient Register and we followed up the cohort between 1991 and 2009 at ages 40-60 years. Exposure to occupational lifting was assessed by applying a job exposure matrix to occupational data from the 1990 census. Incidence rate ratios (IRRs) and 95% CIs were estimated through Poisson regression models adjusted by degree of myopia, income and education level., Results: We observed 217 cases of RRD in 7 80 166 person-years. In univariate analyses we did not observe an association between occupational lifting and RRD. However, after adjustment for myopia and socioeconomic factors, we found an increased risk of RRD (IRR 2.38, 95% CI 1.15 to 4.93) for subjects in the highest category of exposure compared with those in the lowest one. The incidence rate of RRD among subjects lifting heavy loads at least twice per week, aged between 50 years and 59 years, and affected by severe myopia was as high as 7.9 cases per 1000 person-years, compared with an overall rate of 0.28., Conclusions: Our study supports the hypothesis that heavy occupational lifting is a risk factor for RRD. Information on myopia degree and socioeconomic status is necessary when studying the association between occupational lifting and RRD., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Objectives: In countries with ageing populations, home care (HC) aides are among the fastest growing jobs. There are few quantitative studies of HC occupational safety and health (OSH) conditions. The objectives of this study were to: (1) assess quantitatively the OSH hazards and benefits for a wide range of HC working conditions, and (2) compare OSH experiences of HC aides who are employed via different medical and social services systems in Massachusetts, USA., Methods: HC aides were recruited for a survey via agencies that employ aides and schedule their visits with clients, and through a labour union of aides employed directly by clients or their families. The questionnaire included detailed questions about the most recent HC visits, as well as about individual aides' OSH experiences., Results: The study population included 1249 HC aides (634 agency-employed, 615 client-employed) contributing information on 3484 HC visits. Hazards occurring most frequently related to musculoskeletal strain, exposure to potentially infectious agents and cleaning chemicals for infection prevention and experience of violence. Client-hired and agency-hired aides had similar OSH experiences with a few exceptions, including use of sharps and experience of verbal violence., Conclusions: The OSH experience of HC aides is similar to that of aides in institutional healthcare settings. Despite OSH challenges, HC aides enjoy caring for others and the benefits of HC work should be enhanced. Quantification of HC hazards and benefits is useful to prioritise resources for the development of preventive interventions and to provide an evidence base for policy-setting., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Risk of aplastic anemia (AA) from occupational exposures to pesticides and industrial chemicals was evaluated in a hospital-based case control study in Thailand (541 cases of AA and 2261 controls). Exposure data were obtained via participants' self-reports and by experts' assessments and the data from these 2 exposure assessment methods were compared. There was an increased risk of AA associated with several classes of pesticides measured by either self-report or expert assessment. The strongest associations were seen in those whose exposures were identified both by self-report and by expert assessment. Comparing very high/high to no exposure, odds ratios (95% confidence intervals) were as follows: for organophosphates 3.20 (1.87-5.46), carbamates 4.75 (1.92-11.75), organochlorines 6.04 (1.31-27.84), and paraquat 2.17 (1.11-4.25). There were correlations among the pesticides because many types were used in the same job, so it was not possible to determine whether these risks were independent or because of confounding of one by another.

Background: Sharps injuries (SI) and other blood/body fluid exposures (BBFE) present bloodborne pathogen risks for home healthcare (HHC) workers. While SI and BBFE are sufficiently frequent in HHC to be serious public health concerns, even moderately large surveys can still have insufficient power to identify risk factors. In this study, a new conceptual model for using near-misses for SI and BBFE was developed and its utility in statistical analyses of SI and BBFE risk factors was evaluated., Methods: A survey of HHC nurses (n = 787) and aides (n = 282) gathered data on the numbers of SI, BBFE, and near-misses in the past year. Questions focused on the circumstances leading up to the SI, BBFE, and near-misses. After evaluating the hypothesis that near-misses and events lie along the same causal pathway, we combined these outcomes to estimate their association with an important risk factor: employment status., Results: There were similar frequencies of risk factors for the events SI, BBFE, and their near-misses, suggesting that they may share common causal pathways. Combined data on events and near-misses confirmed our hypothesis that part-time and temporary HHC aides were at higher risk than full-timers., Conclusions: Analyses combining injuries and near-misses may be useful in risk factor investigations., (© 2010 Wiley-Liss, Inc.)

Background: Often in exposure assessment for epidemiology, there are no highly accurate exposure data and different measurement methods are considered. The objective of this study was to use various statistical techniques to explore agreement between individual reports and expert ratings of workplace exposures in several industries and investigate the sociodemographic influences on this agreement., Methods: A cohort of 1,282 employees at 4 industries/14 worksites answered questions on workplace physical, chemical, and psychosocial exposures over the past 12 months. Occupational hygienists constructed job exposure matrices (JEMs) based on worksite walkthrough exposure evaluations. Worker self-reports were compared with the JEMs using multivariable analyses to explore discord., Results: There was poor agreement between the self-reported and expert exposure assessments, but there was evidence that agreement was modified by sociodemographic characteristics. Several characteristics including gender, age, race/ethnicity, hourly wage and nativity strongly affected the degree of discord between self-reports and expert raters across a wide array of different exposures., Conclusions: Agreement between exposure assessment tools may be affected by sociodemographic characteristics. This study is cross-sectional and therefore, a snapshot of potential exposures in the workplace. Nevertheless, future studies should take into account the social contexts within which workplace exposures occur., (© 2010 Wiley-Liss, Inc.)

Objectives: We quantified risks of sharp medical device (sharps) injuries and other blood and body fluid exposures among home health care nurses and aides, identified risk factors, assessed the use of sharps with safety features, and evaluated underreporting in workplace-based surveillance., Methods: We conducted a questionnaire survey and workplace-based surveillance, collaborating with 9 home health care agencies and 2 labor unions from 2006 to 2007., Results: Approximately 35% of nurses and 6.4% of aides had experienced at least 1 sharps injury during their home health care career; corresponding figures for other blood and body fluid exposures were 15.1% and 6.7%, respectively. Annual sharps injuries incidence rates were 5.1 per 100 full-time equivalent (FTE) nurses and 1.0 per 100 FTE aides. Medical procedures contributing to sharps injuries were injecting medications, administering fingersticks and heelsticks, and drawing blood. Other contributing factors were sharps disposal, contact with waste, and patient handling. Sharps with safety features frequently were not used. Underreporting of sharps injuries to the workplace-based surveillance system was estimated to be about 50%., Conclusions: Sharps injuries and other blood and body fluid exposures are serious hazards for home health care nurses and aides. Improvements in hazard intervention are needed.

Background: While there is a general consensus about the ability of benzene to induce acute myeloid leukemia (AML), its effects on chronic lymphoid leukemia and multiple myeloma (MM) are still under debate. We conducted a population-based case-control study to evaluate the association between exposure to organic solvents and risk of myeloid and lymphoid leukemia and MM., Methods: Five hundred eighty-six cases of leukemia (and 1,278 population controls), 263 cases of MM (and 1,100 population controls) were collected. Experts assessed exposure at individual level to a range of chemicals., Results: We found no association between exposure to any solvent and AML. There were elevated point estimates for the associations between medium/high benzene exposure and chronic lymphatic leukemia (OR = 1.8, 95% CI = 0.9-3.9) and MM (OR = 1.9, 95% CI = 0.9-3.9). Risks of chronic lymphatic leukemia were somewhat elevated, albeit with wide confidence intervals, from medium/high exposure to xylene and toluene as well., Conclusions: We did not confirm the known association between benzene and AML, though this is likely explained by the strict regulation of benzene in Italy nearly three decades prior to study initiation. Our results support the association between benzene, xylene, and toluene and chronic lymphatic leukemia and between benzene and MM with longer latencies than have been observed for AML in other studies., (Copyright 2008 Wiley-Liss, Inc.)

Background: Firefighters are known to be exposed to recognized or probable carcinogens. Previous studies have found elevated risks of several types of cancers in firefighters., Methods: Standardized morbidity odds ratio (SMORs) were used to evaluate the cancer risk in white, male firefighters compared to police and all other occupations in the Massachusetts Cancer Registry from 1986 to 2003. Firefighters and police were identified by text search of the usual occupation field. All other occupations included cases with identifiable usual occupations not police or firefighter. Control cancers were those not associated with firefighters in previous studies., Results: Risks were moderately elevated among firefighters for colon cancer (SMOR = 1.36, 95% CI: 1.04-1.79), and brain cancer (SMOR = 1.90, 95% CI: 1.10-3.26). Weaker evidence of increased risk was observed for bladder cancer (SMOR = 1.22, 95% CI: 0.89-1.69), kidney cancer (SMOR = 1.34, 95% CI: 0.90-2.01), and Hodgkin's lymphoma (SMOR = 1.81, 95% CI: 0.72-4.53)., Conclusions: These findings are compatible with previous reports, adding to the evidence that firefighters are at increased risk of a number of types of cancer., ((c) 2008 Wiley-Liss, Inc.)

Objectives: To examine the effect of job strain on survey response., Methods: 1,613 health care workers received a self-administered questionnaire. Thirty percent of them completed the survey on personal time without any personal monetary compensation. Working conditions were extracted by job title from the national database O*NET 6.0. Job strain was defined as the ratio of job demands to job control. Two complementary models (multi-level logistic and binomial pseudo Poisson regressions) were used to model individual survey response as a function of individual level demographic variables (age and gender), job-level socioeconomic status (SES) and job strain, and facility type (third level)., Results: Survey response was associated with higher SES and with less job strain. The association of SES and survey response was mediated by job strain., Conclusion: Employees' exposure to job strain may be an important influence on survey response, at least for workers who are not compensated for their time in completing a survey., ((c) 2008 Wiley-Liss, Inc.)

Background: Most occupational studies evaluate a single exposure in relation to a particular disease. However, workers typically experience multiple exposures simultaneously. There is also increasing evidence of disparities in health by sociodemographic characteristics, mostly related to social position such as gender, race/ethnicity, immigration status, income, and education. Little information exists on the worker experience of multiple occupational exposures as they vary among social groups. The objectives of this article were to: assess the burden of exposures reported within 1 year by a socially diverse population working in a range of industries; and evaluate whether sociodemographic characteristics affected the patterns of these exposures., Methods: Study participants were from 14 unionized worksites in meat processing, electrical lighting manufacturing, retail grocery stores, and school bus driving. A cross-sectional study design used a self-administered, computer-assisted questionnaire (English and Spanish) to assess sociodemographic characteristics and nine workplace exposures, within the past year. An interviewer-administered job history also was collected., Results: Twelve hundred eighty-two workers (72%) completed the survey: 36% women, 23% Latino, 39% black, 24% white, and 48% born outside the US. The prevalence of high exposures ranged from 21% (chemicals) to 39% (neck strain). Forty-six percent reported three or more high exposures. Exposure reporting varied among sociodemographic groups. Some of the disparities were explained by the jobs held by different groups, but after statistically controlling for job, many disparities remained., Conclusions: Sociodemographic characteristics should be considered when conducting exposure assessments using questionnaires. More research is needed to understand how social characteristics may influence exposures.

Complex and dynamic physiologic processes underlie the exposure-response relations that occupational and environmental epidemiologists study. Simple summary measures of exposure such as the average, cumulative exposure, or duration of exposure, can be applied suitably in exposure-response analyses in many instances. However, there are situations where these metrics may not be directly proportional to risk, in which case their use will result in misclassification and biased estimates of exposure-response associations. We outline methods for developing exposure or dose metrics which may reduce misclassification, as illustrated with some recent examples. Selecting better exposure or dose metrics can be thought of as a problem of choosing appropriate weights on the exposure history of each cohort member. Dosimetric modeling involves choosing exposure weights based on formal hypotheses about underlying physiologic or pathogenetic processes. Dosimetric modeling is still not widely used in epidemiology, and so the forms of mathematical models and the criteria for choosing one model over another are not yet standardized. We hope to stimulate further applications through this presentation.

Background: A number of studies have shown possible associations between occupational exposures, particularly solvents, and lymphomas. The present investigation aimed to evaluate the association between exposure to solvents and lymphomas (Hodgkin and non-Hodgkin) in a large population-based, multicenter, case-control study in Italy., Methods: All newly diagnosed cases of malignant lymphoma in men and women age 20 to 74 years in 1991-1993 were identified in 8 areas in Italy. The control group was formed by a random sample of the general population in the areas under study stratified by sex and 5-year age groups. We interviewed 1428 non-Hodgkin lymphoma cases, 304 Hodgkin disease cases, and 1530 controls. Experts examined the questionnaire data and assessed a level of probability and intensity of exposure to a range of chemicals., Results: Those in the medium/high level of exposure had an increased risk of non-Hodgkin lymphoma with exposure to toluene (odds ratio = 1.8; 95% confidence interval = 1.1-2.8), xylene 1.7 (1.0-2.6), and benzene 1.6 (1.0-2.4). Subjects exposed to all 3 aromatic hydrocarbons (benzene, toluene, and xylene; medium/high intensity compared with none) had an odds ratio of 2.1 (1.1-4.3). We observed an increased risk for Hodgkin disease for those exposed to technical solvents (2.7; 1.2-6.5) and aliphatic solvents (2.7; 1.2-5.7)., Conclusion: This study suggests that aromatic and chlorinated hydrocarbons are a risk factor for non-Hodgkin lymphomas, and provides preliminary evidence for an association between solvents and Hodgkin disease.

Background: Ragpickers are informal workers who collect recyclable materials to earn a small wage. Their life and working conditions are extremely difficult. We examined minor psychiatric disorders (MPD) among a cohort of ragpickers in Pelotas, a city in southern Brazil., Methods: Ragpickers were matched by sex, age, and years of schooling with a sample of non-ragpickers from the same poor neighborhoods. The cross-sectional study gathered data by interview on 990 individuals in 2004. MPD were assessed using a standard self-reporting questionnaire, the SRQ-20., Results: The prevalence of MPD among ragpickers was 44.7%, higher than reported by neighborhood controls (33.6%; p < 0.001). MPD were more common among females, those of lower economic level, smokers and alcoholics. Among occupational characteristics, MPD prevalence was associated with frequent static postures, low job satisfaction and recent work accidents., Conclusion: Ragpickers more frequently report MPD than other poor workers living in the same neighborhoods, with many of the same life conditions. Improving the work lives of these precarious workers should address not only the physical hazards of their jobs but their mental and emotional health as well.

The objectives of this study were to document the high rates of acute injuries and physical assaults among nurses and certified nursing assistants working in long-term psychiatric care facilities and to identify risk factors for assaults and injuries to inform prevention strategies. A mixed-design cohort study was conducted. Acute injury and physical assault data were obtained from administrative records. Using staff rosters and schedule records, incidence rates were calculated by job title, gender, shift, and floor. Rates were also reported by severity, body part, type, and nature. Targeted interviews with staff members provided measures of physical lifting and resident combativeness. Injury rates were calculated by degree of lifting and assault rates were calculated by degree of resident combativeness. Overall rates of injuries (55.6 per 100 person-years) and assaults (67.3 per 100 person-years) were substantially higher than expected. Predictably, injuries were associated with resident lifting and assaults were associated with contact with combative residents. A higher risk of assault was found among women and higher risks of injury and assault were observed among full-time employees compared to per diem or pool agency workers. In addition, weekend shifts were found to have a higher rate of injuries and a lower rate of assaults than weekday shifts. In similar long-term care facilities with psychiatric populations, efforts should be made to reduce lifting and avoid circumstances that agitate residents. Work organization factors should be taken into consideration when developing interventions.

Background: Exposure to metalworking fluids has been previously associated with prostate cancer mortality in a cohort of autoworkers. Our objective was to further explore this finding in a study of prostate cancer incidence in the same cohort, with reduced misclassification of outcome., Methods: We conducted a nested case-control study in the General Motors cohort of autoworkers. Incident cases of prostate cancer (n = 872) were identified via the Michigan Cancer Registry from 1985 through 2000. Controls were selected using incidence-density sampling with 5:1 ratio. Using cumulative exposure (mg/m-years) as the dose metric, we first examined varying lengths of lags (0-25 years). Then, we evaluated consecutive windows of exposure: 25 or more years before risk age, and fewer than 25 years. We used penalized splines to model the relative risk as a smooth function of exposure, and adjusted for race and calendar year of diagnosis in a Cox model., Results: Risk of prostate cancer increased with exposure to soluble and straight fluids 25 years or more before risk age but not with exposure in the last 25 years. The relationship with soluble fluids was piecewise linear, with a small increase in risk at lower exposures followed by a steeper rise. By contrast, the relationship with straight fluids was linear, with a relative risk of 1.12 per 10mg/m-years of exposure (95% confidence interval = 1.04-1.20)., Conclusions: Exposure to oil-based fluids, soluble and straight, is modestly associated with prostate cancer risk among autoworkers, with a latency period of at least 25 years.

Objective: Results are presented for a registry-based study of hepatobiliary cancer (liver and biliary tract) nested in a cohort of workers from three automobile manufacturing plants with potential exposure to metalworking fluids., Methods: Altogether 63 cases of hepatobiliary cancer were identified from the cohort by the Michigan cancer registries. Each case was matched to 10 controls. Odds ratios (OR) were estimated in conditional logistic regression models for lifetime exposure to straight, soluble, and synthetic metalworking fluid and fluid components., Results: Overall, hepatobiliary cancer was not associated with exposure to metalworking fluids. However, when the cases were stratified into liver cancer (N = 39) and biliary tract cancer (N = 24) the risk was nonhomogeneous across the two categories. While liver cancer was not associated with exposure to metalworking fluids, the results suggested a possible excess risk of biliary tract cancer with more than 1.0 mg/m3-years of exposure to straight metalworking fluids [OR 2.7, 95% confidence interval (95% CI) 0.9-7.6], as well as any exposure to chlorinated paraffins (OR 3.9, 95% CI 0.9-17). When exposures to straight metalworking fluids were separated into 10-year exposure periods, the odds ratio increased to 6.24 (95% CI 1.62-24.16) for exposures occurring > 20 years prior to the risk date., Conclusions: There is limited evidence that exposure to straight metalworking fluids is associated with biliary tract cancer. The small numbers of cases of these rare cancers were reflected in the wide confidence intervals, and these findings need to be examined further in other exposed populations.

Objective: Prostate cancer is hormone-related and chemicals that interfere with hormones may contribute to carcinogenesis. In a cohort of autoworkers we characterized exposure to metalworking fluids (MWF) into age windows with homogenous biological risk for prostate cancer, and examined exposure-response relationships using semi-parametric modeling., Methods: Incident cases (n=872) were identified via Michigan cancer registry from 1985 through 2000. Controls were selected using incidence-density sampling, 5:1 ratio. Using a hormonal-based model, exposure was accumulated in three windows: (1) late puberty, (2) adulthood, and (3) middle age. We used penalized splines to model risk as a smooth function of exposure, and controlled for race and calendar year of diagnosis in a Cox model., Results: Risk of prostate cancer linearly increased with exposure to straight MWF in the first window, with a relative risk of 2.4 per 10 mg/m(3)-years. Autoworkers exposed to MWF at a young age also had an increased risk associated with MWF exposure incurred later in life. For soluble MWF there was a slightly increased risk in the third window., Conclusions: Exposure characterization based on a hormonal model identified heightened risk with early age of exposure to straight MWF. Results also support a long latency period for exposure related prostate cancer.

Background: Metalworking fluids (MWF) are used for lubrication during metal manufacturing. Previous studies have observed increased risks of several cancers among MWF-exposed workers. We hypothesized that MWF may be associated with risk of breast cancer because they can contain carcinogenic or endocrine-disrupting chemicals., Methods: We conducted a case-control study nested in a cohort of 4,680 female automobile workers employed for at least 3 years between 1/1/41 and 1/1/85, with follow-up through 1994. Cases were identified using the National Death Index (NDI), Michigan cancer registries, and company records. Detailed quantitative MWF exposure data were available for each subject, although data on known breast cancer risk factors were not., Results: Ninety-nine cases of breast cancer and 626 matched controls were identified. There was a weak positive association between lifetime cumulative exposure to soluble MWF and breast cancer risk, but no evidence of association with either straight or synthetic fluids. When exposure was divided into time-windows, the association was strongest for soluble MWF in the decade preceding diagnosis. Controlling for earlier exposures, there was an odds ratio of 1.18 (95% CI=1.02-1.35) per mg/m3-year of cumulative exposure to soluble MWF in this 10-year period., Conclusion: This hypothesis-generating study provides some preliminary evidence for an association between exposure to soluble MWF and increased risk of breast cancer. Additional studies of MWF and breast cancer, with data on known breast cancer risk factors, are warranted.

Background: Among epidemiologic studies that found evidence for associations between exposures to metal working fluids (MWF) and pulmonary function impairments, one found effects restricted to workers with fixed obstruction at baseline. We reanalyzed a previously published study on MWF exposure and cross-shift pulmonary function to further evaluate this finding., Methods: Pulmonary function was measured cross-shift on Monday and Friday in 131 male automotive workers. Quantitative personal MWF exposure data were available. Those with an FEV(1)/FVC ratio of