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BackgroundHybrid immunity, from COVID-19 vaccination followed by SARS-CoV-2 infection acquired after its Omicron variant began predominating, has provided greater protection than vaccination alone against subsequent infection over 1-3 months of observation. Its longer-term protection is unknown.MethodsWe conducted a retrospective cohort study of COVID-19 case incidence among healthcare personnel (HCP) mandated to be vaccinated and report on COVID-19-associated symptoms, high-risk exposures, or known-positive test results to an employee health hotline. We compared cases with hybrid immunity, defined as incident COVID-19 during the first 6 weeks of Omicron-variant predominance (run-in period), to those with immunity from vaccination alone during the run-in period. Time until COVID-19 infection over 13 subsequent months (observation period) was analyzed by standard survival analysis.ResultsOf 5867 employees, 641 (10.9%, 95% confidence interval [CI]: 10.1%-11.8%) acquired hybrid immunity during the run-in period. Of these, 104 (16.2%, 95% CI: 13.5%-19.3%) experienced new SARS-CoV-2 infection during the 13-month observation period, compared to 2177 (41.7%, 95% CI: 40.3%-43.0%) of the 5226 HCP without hybrid immunity. Time until incident infection was shorter among the latter (hazard ratio: 3.09, 95% CI: 2.54-3.78).ConclusionsIn a cohort of vaccinated employees, Omicron-era acquired SARS-CoV-2 hybrid immunity was associated with significantly lower risk of subsequent infection over more than a year of observation-a time period far longer than previously reported and during which three, progressively more resistant, Omicron subvariants became predominant. These findings can inform institutional policy and planning for future COVID-19 additional vaccine dosing requirements for employees, for surveillance programs, and for risk modification efforts.

ObjectiveOccupational health (OH) documentation has traditionally been separate from health system electronic health records (EHRs), but this can create patient safety and care continuity challenges. Herein, we describe outcomes and challenges of such integration including how one health system managed compliance with laws, regulations, and ethical principles concerning digital privacy.MethodsOccupational health integration with the enterprise EHR at the University of California San Diego Health was started in June 2021 and completed in December 2021.ResultsIntegrating with the enterprise EHR allowed for a secure telehealth system, faster visit times, digitization of questionnaires medical clearance forms, and improved reporting capabilities.ConclusionsIntegration and interoperability are fundamental building blocks to any OH EHR solution and will allow for evaluation of worker population trends, and targeted interventions to improve worker health status.

ObjectiveEstimate the association between environmental temperature (wet bulb globe temperature [WBGT]) and work rate over the course of a workday.MethodsRepeated-measures regression was used to identify characteristics impacting work rate in a cross-sectional study of Latino farmworkers. Minute-by-minute work rate (measured by accelerometer) and WBGT were averaged over 15-minute intervals.ResultsWork rate decreased by 4.34 (95% confidence interval [CI], -7.09 to -1.59) counts per minute per degree Celsius WBGT in the previous 15-minute interval. Cumulative quarter hours worked (2.13; 95% CI, 0.82 to 3.45), age (-3.64; 95% CI, -4.50 to -2.79), and dehydration at the end of workday (51.37; 95% CI, 19.24 to 83.50) were associated with counts per minute as were gender, pay type (piece rate vs hourly) and body mass index ≥25 kg/m 2 . The effects of pay type and body mass index were modified by gender.ConclusionIncreased temperature was associated with a decrease in work rate.

ObjectivesWork-related psychosocial stressors have been recognized as occupational hazards and assessed in workplaces in many countries for decades. Identifying tools to measure work-related psychosocial hazards to increase awareness in the United States about the impact on employees' health and safety is critical ( J Occup Environ Med. 2021;63:e245-e249).MethodsWe describe the development and psychometric validation of an online tool, the Healthy Work Survey, utilizing items from the National Institute for Occupational Safety and Health Quality of Work Life questionnaire.ResultsThere are 55 items in the final core work section of the HWS. Factor analyses confirmed nine factors, and the subsequent multi-item scales had acceptable internal consistency. A user-friendly, online system and automated report compares individual's and organization's scores to distributions from a representative US working population (General Social Survey Quality of Work Life).DiscussionThe HWS is a reliable, valid tool for organizations and individuals to assess psychosocial work hazards.

ObjectiveThe aim of the study is to examine associations between years of firefighting service and eight chronological age-adjusted measures of blood leukocyte epigenetic age acceleration: Horvath, Hannum, SkinBloodClock, Intrinsic, Extrinsic, PhenoAge, GrimAge, and DNAm telomere length.MethodsThe study used a repeated measures analysis of data from 379 incumbent firefighters from eight career departments and 100 recruit firefighters from two of the departments, across the United States.ResultsIncumbent firefighters had on average greater epigenetic age acceleration compared with recruit firefighters, potentially due to the cumulative effect of occupational exposures. However, among incumbent firefighters, additional years of service were associated with epigenetic age deceleration, particularly for GrimAge, a strong predictor of mortality.ConclusionsLong-term studies with more specific occupational exposure classification are needed to better understand the relationship between years of service and aging biomarkers.

All-terrain vehicle (ATV) incidents are one of the leading causes of injuries and fatalities among youth in the agricultural industry. It has been hypothesized that many youth-related ATV incidents occur because children ride ATVs that do not fit their capabilities and are not following basic safe riding practices. In addition, various ATV safety guidelines regarding youth (e.g., CPSC, ANSI/SVIA, ASI) are inconsistent and may not align with state or local laws. To the best of our knowledge, no comprehensive studies have compared the physical and mental requirements for riding ATVs and the youth's capabilities to ride ATVs safely. Consequently, there are no scientific-based recommendations for age limitation, physical and mental capabilities, and safety requirements for youth to ride ATVs safely. Thus, there is a need to review the available sources related to youth safety and ATVs in the agricultural industry, identify the research voids, and recommend modifications to current ATV guidelines. This study conducted a systematic review of available ATV-related studies, standards, guidelines, and laws to establish better-informed minimum age, physical and mental capabilities, and safety requirements for youths to ride ATVs on the farm.

BACKGROUND: Low job control may predict shorter breastfeeding (BF) among working mothers and may contribute to racial disparities in BF. METHODS: We used demographic, employment, and health data for n = 631 observations from the Panel Study of Income Dynamics. Job control scores came from a job-exposure matrix.Using path analysis, we assessed whether job control predicted BF and mediated Black-White BF differences. We controlled for education, working hours, marital status, and low birthweight. RESULTS: Lower job control predicted decreased odds of BF for at least 6 months (odds ratio, 0.61; 95% confidence interval, 0.31-0.90; reference, no BF). Low job control explained 31% of the Black-White difference for both shorter-term and longer-term BF. CONCLUSIONS: Low job contributes to shorter BF and to BF disparities by race. Intervening to enhance job control could improve BF.

ObjectiveThis study aimed to determine the prevalence of anemia and overweight/obesity and assess the relationships between hematocrit (Hct) and body mass index (BMI), and between fatigue and Hct, among a sample of farmworkers in California.MethodsWe estimated the prevalence of anemia (using Hct), overweight/obesity (BMI ≥25 kg/m 2 ), and self-reported fatigue in 587 farmworkers. Multivariable linear and logistic regression models were used to examine the associations between Hct and BMI, and between fatigue and Hct.ResultsAnemia prevalence was 3.1%, overweight/obesity prevalence was 80.7%, and 78% of workers reported fatigue at work. There was no association between Hct and BMI or between Hct and reported fatigue. Women were more likely than men to have lower Hct and higher BMI.ConclusionsA majority of farmworkers in this sample were overweight/obese, but anemia was uncommon. Anemia among more vulnerable subgroups of farmworkers should be explored.

BackgroundAlthough recent studies have identified important risk factors associated with incident carpal tunnel syndrome (CTS), risk factors associated with its severity have not been well explored.ObjectiveTo examine the associations between personal, workplace psychosocial and biomechanical factors and incident work disability among workers with CTS.MethodsBetween 2001 and 2010 five research groups conducted coordinated prospective studies of CTS and related work disability among US workers from various industries. Workers with prevalent or incident CTS (N=372) were followed for up to 6.4 years. Incident work disability was measured as: (1) change in work pace or work quality, (2) lost time or (3) job change following the development of CTS. Psychosocial factors were assessed by questionnaire. Biomechanical exposures were assessed by observation and measurements and included force, repetition, duty cycle and posture. HRs were estimated using Cox models.ResultsDisability incidence rates per 100 person-years were 33.2 for changes in work pace or quality, 16.3 for lost time and 20.0 for job change. There was a near doubling of risk for job change among those in the upper tertile of the Hand Activity Level Scale (HR 2.17; 95% CI 1.17 to 4.01), total repetition rate (HR 1.75; 95% CI 1.02 to 3.02), % time spent in all hand exertions (HR 2.20; 95% CI 1.21 to 4.01) and a sixfold increase for high job strain. Sensitivity analyses indicated attenuation due to inclusion of the prevalent CTS cases.ConclusionPersonal, biomechanical and psychosocial job factors predicted CTS-related disability. Results suggest that prevention of severe disability requires a reduction of both biomechanical and organisational work stressors.

BackgroundMany workers seek care for work-related medical conditions in primary care settings. Additionally, occupational medicine training is not consistently addressed in primary care professional training. These patterns raise concerns about the health outcomes of low-wage Latina/o immigrant workers who make use of primary care settings to obtain care for work-related injuries and illnesses. The objective of this qualitative study was to investigate how primary care clinicians assessed and addressed the role of occupational exposures on the health and well-being of Latina/o immigrant workers.MethodsWe conducted semistructured in-depth interviews with 17 primary care clinicians (physicians, resident physicians, and nurse practitioners) employed in an urban federally qualified health center (FQHC) with two sites located in Orange County, CA.ResultsUsing a constructivist grounded theory approach, we determined that primary care clinicians had a general understanding that employment influenced the health and well-being of their Latina/o immigrant patients. Clinicians delivered care to Latina/o immigrant workers who feared reporting their injury to their employer and to Latina/o immigrants whose workers' compensation claim was terminated before making a full recovery. Clinicians were responsive to patients' work-related concerns and leveraged the resources available within the FQHC. Although some clinicians offered suggestions to improve occupational health in the FQHC, a few clinicians raised concerns about the feasibility of additional health screenings and clinic-based interventions, and pointed to the importance of interventions outside of the healthcare system.ConclusionThis study underscores the complexities of addressing occupational health concerns in urban FQHCs.

ObjectiveThe objective was to (i) assess the long-term cost-effectiveness of acceptance and commitment therapy (ACT), a workplace dialog intervention (WDI), and ACT+WDI compared to treatment as usual (TAU) for common mental disorders and (ii) investigate any differences in cost-effectiveness between diagnostic groups.MethodsAn economic evaluation from the healthcare and limited welfare perspectives was conducted alongside a randomized clinical trial with a two-year follow-up period. Persons with common mental disorders receiving sickness benefits were invited to the trial. We used registry data for cost analysis alongside participant data collected during the trial and the reduction in sickness absence days as treatment effect. A total of 264 participants with a diagnosis of depression, anxiety, or stress-induced exhaustion disorder participated in a two-year follow-up of a four-arm trial: ACT (N=74), WDI (N=60), ACT+WDI (N=70), and TAU (N=60).ResultsFor all patients in general, there were no statistically significant differences between interventions in terms of costs or effect. The subgroup analyses suggested that from a healthcare perspective, ACT was a cost-effective option for depression or anxiety disorders and ACT+WDI for stress-induced exhaustion disorder. With a two-year time horizon, the probability of WDI to be cost-saving in terms of sickness benefits costs was 80% compared with TAU.ConclusionsACT had a high probability of cost-effectiveness from a healthcare perspective for employees on sick leave due to depression or anxiety disorders. For participants with stress-induced exhaustion disorder, adding WDI to ACT seems to reduce healthcare costs, while WDI as a stand-alone intervention seems to reduce welfare costs.

(1) Describe knowledge, attitudes, beliefs, and behaviors related to coccidioidomycosis (Valley fever, VF) reported by farm workers in a highly endemic area to design and evaluate prevention messages and (2) identify health information sources preferred by farm workers to disseminate VF prevention messages. There were 119 primarily Mexican-born residents of two migrant farm labor housing centers in Kern County, who completed an interviewer-administered survey on VF knowledge, attitudes, beliefs, and behaviors in 2017. The 73% of participants aware of VF demonstrated a knowledge score of 53%. Over 90% erroneously believed VF was associated with pesticide exposure; approximately two-thirds believed that wearing a bandana mask was protective. Over half of respondents believed that VF was contagious, could be contracted from contaminated food or water, and caused gastrointestinal symptoms. Of those aware of VF, 75% expressed concern about becoming infected because of where they lived and working outdoors. Working outdoors in dusty conditions was the most commonly reported risk-associated work practice. Among 67 participants reporting use of respiratory protection, 94% indicated they wear a bandana; most male participants did not wear face coverings in dusty conditions. The most frequent protective work practice was wetting soil. Preferred sources of health information included television; family, friend, or co-worker; healthcare provider; and radio. Farm workers reported multiple risk factors for VF. Results identified several areas of poor knowledge, risk behavior, and preferred channels of prevention messages. Important protective behaviors are not under the control of farm workers; engagement with employers is essential.

Household air pollution is a leading risk factor for morbidity and premature mortality. Numerous cookstoves have been developed to reduce household air pollution, but it is unclear whether such cookstoves meaningfully improve health. In a controlled exposure study with a crossover design, we assessed the effect of pollution emitted from multiple cookstoves on acute differences in blood lipids and inflammatory biomarkers. Participants (n = 48) were assigned to treatment sequences of exposure to air pollution emitted from five cookstoves and a filtered-air control. Blood lipids and inflammatory biomarkers were measured before and 0, 3, and 24 hours after treatments. Many of the measured outcomes had inconsistent results. However, compared to control, intercellular adhesion molecule-1 was higher 3 hours after all treatments, and C-reactive protein and serum amyloid-A were higher 24 hours after the highest treatment. Our results suggest that short-term exposure to cookstove air pollution can increase inflammatory biomarkers within 24 hours.

ObjectiveHousehold SARS-COV-2 contact constitutes a high-risk exposure for health care workers (HCWs). Cycle threshold (Ct) of reverse transcriptase-polymerase chain reaction testing provides an estimate of COVID-19 viral load, which can inform clinical and workplace management. We assessed whether Ct values differed between HCWs with COVID-19 with and without household exposure.MethodsWe analyzed HCW COVID-19 cases whose Ct data could be compared. We defined low Ct at a cut-point approximating a viral load of 4.6 × 106 copies per ml. Logistic regression tested the association of household exposure and symptoms at diagnosis with a low Ct value.ResultsOf 77 HCWs with COVID-19, 20 were household exposures cases and 34 were symptomatic at testing (7 were both household-exposed and symptomatic at testing). Among household exposures, 9 of 20 (45%) manifested lower Ct values compared to 14 of 57 (25%) for all others. In a bivariate model, household exposure was not statistically associated with lower Ct (Odds Ratio [OR] 1.20; 95% Confidence Interval [CI] 0.97-1.51). In multivariable modelling both household exposure (OR] 1.3; 95% CI 1.03-1.6) and symptoms at diagnosis (OR 1.4; 95% CI 1.15-1.7) were associated with a low Ct value.DiscussionHousehold exposure in HCWs with newly diagnosed COVID-19 was associated with lower Ct values, consistent with a higher viral load, supporting the hypothesis that contracting COVID-19 in that manner leads to a greater viral inoculum.

Stigma may negatively affect line managers' intention to hire people with mental health problems (MHP). This study aims to evaluate line managers' knowledge and attitudes concerning job applicants with MHP, and to assess which factors are associated with the intention (not) to hire an applicant with MHP. A sample of Dutch line managers (N=670) filled out a questionnaire on their knowledge, attitudes and experiences concerning applicants/employees with MHP. Descriptive analyses and multiple regression analyses were used. The majority (64%) was reluctant to hire a job applicant with MHP, despite the fact that only 7% had negative and 52% had positive personal experiences with such employees. Thirty per cent were reluctant to hire an applicant if they knew the applicant had past MHP. Associated with higher reluctance to hire an applicant with MHP were the concerns that it will lead to long-term sickness absence (β (95% CI)=0.39 (0.23 to 0.55)), that the employee cannot handle the work (β (95% CI)=0.16 (0.00 to 0.33)) that one cannot count on the employee (β (95% CI)=0.41 (0.23 to 0.58)) and higher manager education level (β (95% CI)=0.25 (0.05 to 0.44)). Conversely, associated with positive hiring intentions was being in favour of diversity and/or inclusive enterprise (β(95% CI)=-0.64 (-0.87 to -0.41)). As the majority of managers were reluctant to hire applicants with MHP, and even 30% were reluctant to hire applicants who had past MHP, these findings have major implications for social inclusion in the Netherlands, where about 75% of employees would disclose MHP at work.

ObjectivesThe US National Toxicology Program (NTP) recently recommended in its Report on Carcinogens Monograph for Antimony Trioxide that antimony trioxide be listed as 'reasonably anticipated to be a human carcinogen' based on sufficient evidence of carcinogenicity in experimental animals and supporting evidence from mechanistic studies. Our goal was to estimate the possible human cancer risk from occupational exposure to antimony trioxide.MethodsWe selected data from 2-year inhalation studies in male and female mice conducted by the NTP and performed cancer dose-response analyses using cancer models and benchmark dose methods developed by the US Environmental Protection Agency. In these analyses, we generated benchmark doses and cancer slope factors for antimony trioxide, and then estimated human cancer risk under various exposure scenarios. Typical and worst-case inhalation scenarios in multiple occupational settings were used in risk estimation.ResultsIn typical case scenarios, the occupational cancer risk from antimony trioxide was estimated to be 0.025 (25 in 1000) for persons working with flame retardants in plastics and textiles for 40 years. Under worst-case scenarios, the occupational cancer risk was estimated to be 0.11 (110 in 1000) for persons working with flame retardants in plastics and textiles. At the current Occupational Safety and Health Administration Permissible Exposure Limit, the cancer risk for occupational inhalation exposure of antimony trioxide was estimated to be 0.096 (96 in 1000).ConclusionThe risk estimates calculated in this study suggest that exposure to antimony trioxide at levels present in certain occupational settings results in a large increase in the risk of developing cancer.

BackgroundHealth care workers (HCWs) experience increased occupational risk of contracting COVID-19, with temporal trends that might inform surveillance.MethodsWe analyzed data from a Veterans Affairs hospital-based COVID-19 worker telephone hotline collected over 40 weeks (2020). We calculated the proportion of COVID-19+ cases among persons-under-investigation (PUIs) for illness compared to rates from a nearby large university-based health care institution.ResultsWe observed 740 PUIs, 65 (8.8%) COVID-19+. Time trends were similar at the study and comparison hospitals; only for the first of 10 four-week observation periods was the ratio for observed to expected COVID-19+ significant (P

ObjectiveDetermine compliance with and effectiveness of California regulations in reducing farmworkers' heat-related illness (HRI) risk and identify main factors contributing to HRI.MethodsIn a cross-sectional study of Latino farmworkers, core body temperature (CBT), work rate, and environmental temperature (WBGT) were monitored over a work shift by individual ingestible thermistors, accelerometers, and weather stations, respectively. Multiple logistic modeling was used to identify risk factors for elevated CBT.ResultsAlthough farms complied with Cal/OSHA regulations, worker training of HRI prevention and hydration replacement rates were insufficient. In modeling (AOR [95% CI]) male sex (3.74 [1.22 - 11.54]), WBGT (1.22 [1.08 - 1.38]), work rate (1.004 [1.002 - 1.006]), and increased BMI (1.11 [1.10 - 1.29]) were all independently associated with elevated CBT.ConclusionRisk of HRI was exacerbated by work rate and environmental temperature despite farms following Cal/OSHA regulations.

ObjectiveRecent evidence has accumulated that the immune system is intimately intertwined with cancer development. Two key characteristics of carcinogens in which the immune system plays a central role are chronic inflammation and immunosuppression. In this systematic review, we investigated the association of chronic inflammatory and immunosuppressive outcomes with benzene, a widely used industrial chemical. Benzene has been confirmed to cause acute myeloid leukaemia and suspected to cause non-Hodgkin lymphoma, two cancers of the blood-forming system that affect immune cells.MethodsWe systematically searched PubMed and Embase for all relevant studies using a combination of Medical Subject Headings (MeSH) and selected key words. The detailed review protocol, including search strategy, was registered with PROSPERO, the international prospective register of systematic reviews (#CRD42019138611).ResultsBased on all human studies selected in the final review, we report new evidence of a benzene-induced immunosuppressive effect on the adaptive immune system and activation of the innate immune system to cause inflammation. In particular, benzene significantly lowers the number of white blood cells, particularly lymphocytes such as CD4+ T-cells, B-cells and natural killer cells, and increases proinflammatory biomarkers at low levels of exposure.ConclusionTo the best of our knowledge, this is the first comprehensive review of benzene's immunotoxicity in humans. Based on results obtained from this review, we propose two potential immunotoxic mechanisms of how benzene induces leukaemia/lymphoma: (1) cancer invasion caused by proinflammatory cytokine production, and (2) cancer promotion via impaired immunosurveillance. Further studies will be required to confirm the connection between benzene exposure and its effects on the immune system.

BackgroundResearch investigating the efficacy of workplace wellness programmes to promote exercise, and by extension, reduce obesity and increase productivity has proliferated in recent years. Although preliminary work is encouraging, more work is needed.AimsTo evaluate the effects and overall cost of a workplace exercise programme on multiple physical outcomes, including body mass index, aerobic fitness and muscular fitness.MethodsData from the Bruin Health Improvement Programme .5 (BHIP) between August 2013 and July 2018 were analysed. BHIP is a 12-week workplace wellness programme that assesses multiple areas of physical and mental health. For this study, changes in weight, waist-to-hip ratio, aerobic fitness and muscular endurance were analysed using paired samples t-tests and chi-squared tests. Using results from a prior analysis of Medical Expenditure Panel Survey, the estimated medical expenditure savings associated with weight loss were also analysed.ResultsA total of 518 participants (84% female) took part in the BHIP programme (mean age = 41 years, SD = 1.17). There were significant decreases in all anthropometric indices and significant increases in all fitness outcomes (P < 0.01) from baseline to follow-up. Estimated programme cost per participant, per session was $473 US Dollars (USD), and weight loss is estimated to reduce annual medical care costs by ~$2200 USD.ConclusionsResults showed significant improvements in all physical outcomes of interest. Additionally, there appears to be an inverse relationship between improvements in employee health and employer healthcare costs. Strengths, limitations and future directions are discussed.

ObjectivesWe investigated the association between low-dose external occupational radiation exposure and circulatory disease morbidity among diagnostic medical radiation workers.MethodsA cohort of 11 500 diagnostic medical radiation workers was linked with the National Dosimetry Registry data and the National Health Insurance Service data. Relative risks (RRs) were calculated to explore the association between occupational factors and circulatory disease morbidity, and excess relative risks per 100 milligray (ERR/100 mGy) were estimated to quantify the radiation dose-response relationship.ResultsOverall, there were 2270 cases of circulatory diseases during 93 696 person-years of observation (average follow-up=8.1 years). RRs for hypertension were significantly increased for individuals who started working before 2000 compared with those who started in 2005 and later. ERR/100 mGy for all circulatory diseases was 0.14 (95% CI -0.57 to 0.99). Radiation risks of cerebrovascular diseases and ischaemic heart disease were non-significantly increased with estimates of individual cumulative doses to the heart (ERR/100 mGy=3.10 (-0.75 to 11.59) and 1.22 (-0.71 to 4.73), respectively). However, ERR estimates were generally more strongly positive for female versus male workers and for younger workers versus more than 50-year-old workers.ConclusionsThis study provides little evidence in support of a positive association between occupational radiation exposure and the overall risk of circulatory disease over a short follow-up period among medical radiation workers in South Korea. However, significantly increased RR with earlier year first worked, elevated ERR in female workers and young workers should be further followed up.

ObjectivesTo examine the influence of depression and/or anxiety on work leaves and the impact of work leaves on experiencing a new-onset depression and/or anxiety disorder.MethodsIBM's MarketScan® research databases were linked to investigate depressive and anxiety disorders in workers with a work leave due to an injury or non-mental health illness (n = 467,930) and without a work leave (n = 2,764,447).ResultsThe odds of a work leave within a year were 2.10 times higher (95%CI: 2.08-2.13) in individuals with depression and/or anxiety compared to those without. The odds of developing a new-onset depression and/or anxiety within a year was 4.21 times higher (95% CI: 4.14-4.27) in individuals with a work leave compared to those without.ConclusionDepression and anxiety are both risk factors for and subsequent outcomes of injuries or illnesses that require a work leave.

Objectives This report describes the extended follow-up (1941-2015) of a cohort of 38 549 automobile manufacturing workers with potential exposure to metalworking fluids (MWF). The outcomes of interest were mortality from cancers of the esophagus, stomach, intestine, rectum, bladder, liver, pancreas, larynx, lung, skin, prostate, brain, and female breast, as well as leukemia. This report includes 5472 deaths from cancer, more than ten times the numbers of deaths in our last summary report published 20 years ago. Methods Standardized mortality ratios were computed for the entire study period. Adjusted hazard ratios (HR) were estimated in Cox proportional hazard models with categorical variables for cumulative exposure to each type of MWF. Results Exposure-response patterns are consistent with prior mortality reports from this cohort. We found increased risk of skin and female breast cancer with straight fluids. For the first time, we found elevated risk of stomach cancer mortality. Overall, many of the exposure-response results did not suggest an association with MWF. Conclusions Mortality is a poor proxy for cancer diagnosis for treatable cancers and not the optimal outcome measure in etiological studies. Although the HR presented here handle bias from the healthy worker hire effect and left truncation, they do not handle bias from healthy worker survivor effect, which likely results in underestimates of the health impacts of MWF. Although this updated summary provides some information on the risk of cancer from MWF, targeted future analyses will help clarify associations.

Objectives: Specific work processes and management structures that contribute to high rates of occupational illness and injury in agricultural industries are not well described in academic literature. This qualitative study of work organization in the U.S. fresh tomato industry investigates how work processes and management structures impact tomato workers' occupational health. Methods: After conducting literature review and key informant interviews, semi-structured interviews and focus groups were conducted with 36 individuals with experience working in the U.S. fresh tomato industry. Interviews and focus groups were audio-recorded, transcribed, coded, and analyzed using a modified grounded theory approach. Results: These data indicate that participants endured income insecurity and hazardous supervisory practices, including wage theft, retaliation, intimidation, and humiliation, that put them at risk of preventable illness and injury. Support from workers' organizations and health-conscious supervisory practices helped mitigate some of these occupational hazards. Conclusion: Participants' adverse work experiences may be considered sequelae of workers' lack of job control and positions of socioeconomic structural vulnerability. Other aspects of tomato work organization, including health-conscious supervisory practices and the involvement of workers' organizations, indicate that modifying work organization to better safeguard health is possible. Such modifications present compelling opportunities for employers, employees, organizations, community and government leaders, and health care professionals to help create healthier occupational environments for tomato workers.

ObjectiveTo examine associations with occupational livestock or other animal dust exposure and offspring cancer risk.MethodsIn this population-based case-control study of Danish children aged

OBJECTIVES:Epidemiological studies of underground miners have provided clear evidence that inhalation of radon decay products causes lung cancer. Moreover, these studies have served as a quantitative basis for estimation of radon-associated excess lung cancer risk. However, questions remain regarding the effects of exposure to the low levels of radon decay products typically encountered in contemporary occupational and environmental settings on the risk of lung cancer and other diseases, and on the modifiers of these associations. These issues are of central importance for estimation of risks associated with residential and occupational radon exposures. METHODS:The Pooled Uranium Miner Analysis (PUMA) assembles information on cohorts of uranium miners in North America and Europe. Data available include individual annual estimates of exposure to radon decay products, demographic and employment history information on each worker and information on vital status, date of death and cause of death. Some, but not all, cohorts also have individual information on cigarette smoking, external gamma radiation exposure and non-radiological occupational exposures. RESULTS:The PUMA study represents the largest study of uranium miners conducted to date, encompassing 124 507 miners, 4.51 million person-years at risk and 54 462 deaths, including 7825 deaths due to lung cancer. Planned research topics include analyses of associations between radon exposure and mortality due to lung cancer, cancers other than lung, non-malignant disease, modifiers of these associations and characterisation of overall relative mortality excesses and lifetime risks. CONCLUSION:PUMA provides opportunities to evaluate new research questions and to conduct analyses to assess potential health risks associated with uranium mining that have greater statistical power than can be achieved with any single cohort.

ObjectiveTo develop and validate syringe threat and injury correlates (STIC) score to measure police vulnerability to needlestick injury (NSI).MethodsTijuana police officers (N = 1788) received NSI training (2015 to 2016). STIC score incorporates five self-reported behaviors: syringe confiscation, transportation, breaking, discarding, and arrest for syringe possession. Multivariable logistic regression was used to evaluate the association between STIC score and recent NSI.ResultsTwenty-three (1.5%) officers reported NSI; higher among women than men (3.8% vs 1.2%; P = 0.007). STIC variables had high internal consistency, a distribution of 4.0, a mode of 1.0, a mean (sd) of 2.0 (0.8), and a median (interquartile range [IQR]) of 2.0 (1.2 to 2.6). STIC was associated with recent NSI; odds of NSI being 2.4 times higher for each point increase (P-value

ObjectiveOccupational dust exposure has been associated with accelerated lung function decline, which in turn is associated with overall morbidity and mortality. In the current study, we assess potential benefits on lung function of hypothetical interventions that would reduce occupational exposure to fine particulate matter (PM2.5) while adjusting for the healthy worker survivor effect.MethodsAnalyses were performed in a cohort of 6485 hourly male workers in an aluminium manufacturing company in the USA, followed between 1996 and 2013. We used the parametric g-formula to assess lung function decline over time under hypothetical interventions while also addressing time-varying confounding by underlying health status, using a composite risk score based on health insurance claims.ResultsA counterfactual scenario envisioning a limit on exposure equivalent to the 10th percentile of the observed exposure distribution of 0.05 mg/m3 was associated with an improvement in forced expiratory volume in one second (FEV1) equivalent to 37.6 mL (95% CI 13.6 to 61.6) after 10 years of follow-up when compared with the observed. Assuming a linear decrease and (from NHANES reference values), a 20 mL decrease per year for a 1.8 m-tall man as they age, this 37.6 mL FEV1 loss over 10 years associated with observed exposure would translate to approximately a 19% increase to the already expected loss per year from age alone.ConclusionsOur results indicate that occupational PM2.5 exposure in the aluminium industry accelerates lung function decline over age. Reduction in exposure may mitigate accelerated loss of lung function over time in the industry.

BackgroundOccupational and environmental exposures during the prenatal period may be associated with adverse pregnancy outcomes and lifelong health effects. Yet, identification and evaluation of these potential hazards is lacking in routine obstetric care.AimsTo assess the feasibility of incorporating a self-administered occupational and environmental exposure questionnaire into obstetric clinics.MethodsA cross-sectional survey assessed prenatal clinic patients at a public hospital who were currently employed and

Objectives Parental exposures and offspring's risk of cancer have been studied with inconsistent results. We investigated parental employment in painting and printing industries and risk of childhood leukemia, central nervous system (CNS) cancers, and prenatal cancers (acute lymphoblastic leukemia, Wilms tumor, medulloblastoma, neuroblastoma, retinoblastoma, and hepatoblastoma). Methods Using Danish registries, children aged ≤19 years diagnosed from 1968-2015 with leukemia (N=1999), CNS cancers (N=1111) or prenatal cancers (N=2704) were linked to parents and their employment history one year before birth to birth for fathers, and one year before birth to one year after for mothers. Twenty randomly selected controls per case were matched by age and sex. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated using conditional logistic regression. Results For fathers, we found increased risks for acute myeloid leukemia (AML) consistent in painting (OR 2.26, 95% CI 1.07-4.80) and printing industries (OR 2.43, 95% CI 0.94-6.23) and these industries combined (OR 2.10, 95% CI 1.14-3.87). For mothers, increased risks of CNS cancers were found for painting industries (OR 2.34, 95% CI 1.10-4.95) and painting and printing combined (OR 1.97, 95% CI 1.08-3.64). For fathers working in combined industries, the OR for CNS was increased (OR 1.54, 95% CI 1.02-2.31), most prominently in printing industries (OR 2.09, 95% CI 1.17-3.75). Conclusion We observed increased risks of CNS tumors in offspring after parental employment in painting and printing industries. Children of fathers employed in painting and printing industries had a two-fold increase in AML.

Recent studies have shown the 2001 American Conference of Governmental Industrial Hygienists (ACGIH®) Threshold Limit Value (TLV®) for Hand Activity was not sufficiently protective for workers at risk of carpal tunnel syndrome (CTS). These studies led to a revision of the TLV and Action Limit. This study compares the effect of applying the 2018 TLV vs. the 2001 TLV to predict incident CTS within a large occupational pooled cohort study (n = 4,321 workers). Time from study enrollment to first occurrence of CTS was modeled using Cox proportional hazard regression. Adjusted and unadjusted hazard ratios for incident CTS were calculated using three exposure categories: below the Action Limit, between the Action Limit and TLV, and above the TLV. Workers exposed above the 2001 Action Limit demonstrated significant excess risk of carpal tunnel syndrome, while the 2018 TLV demonstrated significant excess risk only above the TLV. Of 186 total cases of CTS, 52 cases occurred among workers exposed above the 2001 TLV vs. 100 among those exposed above the 2018 value. Eliminating exposures above the 2001 TLV might have prevented 11.2% of all cases of CTS seen in our pooled cohort, vs. 25.1% of cases potentially prevented by keeping exposures below the 2018 value. The 2018 revision of the TLV better protects workers from CTS, a recognized occupational health indicator important to public health. A significant number of workers are currently exposed to forceful repetitive hand activity above these guidelines. Public health professionals should promulgate these new guidelines and encourage employers to reduce hand intensive exposures to prevent CTS and other musculoskeletal disorders.

IntroductionThere is a lack of consistent study findings on associations between workplace exposures and the risk of Parkinson disease (PD) and a paucity of such data on women. We assessed PD risk among occupational groups to derive insights about potential occupation-specific exposures in a large cohort of women.MethodsThe Women's Health Initiative Observational Study (WHI-OS) is a prospective cohort that enrolled 91 627 postmenopausal women, 50 to 79 years of age, from 01 October 1993 through 31 December 1998, at 40 clinical centers across the United States, with average follow-up interval of 11 years. These women reported up to three paid jobs, held the longest since age 18; these jobs were coded and duration of employment calculated. We defined a case by self-report of doctor-diagnosed PD (at baseline or follow-up), death attributed to PD, or taking medication consistent with PD.ResultsAmong 2590 PD cases, we found evidence of excess risk among "counselors, social workers, and other community and social service specialists," and there was a suggestion of increased in risk among postsecondary teachers, and "building and grounds cleaning and maintenance" workers. There was also evidence of a deficit in risk among women who worked in sales. Results according to ever-employed and job duration were similar, except for evidence of excess risk among "health technologists and technicians" with more than 20 years of employment. Longer duration of life on a farm was associated with higher risk.ConclusionOur findings paint a largely reassuring picture of occupational risks for PD among US women.

BackgroundJob satisfaction is associated with health and productivity. Workplace support for breastfeeding may affect working mothers' job satisfaction.MethodsWe analyzed responses from 488 women from the Infant Feeding Practices Study II (2005-2007). Using logistic regression, we assessed whether workplace breastfeeding problems at 3 months postpartum were related to low job satisfaction concurrently and, for a subsample (n = 265), at 9 and 12 months postpartum.ResultsCompared with women reporting no problems, women reporting three or more problems had higher odds (odds ratio [OR] = 4.76; 95% confidence interval [CI]: 2.03-11.18) of low job satisfaction at 3 months, and at 12 months (OR = 6.88, 95% CI: 1.33-35.58) after controlling for baseline job satisfaction. Models isolating problems with break time and space to pump/nurse showed more modest results.ConclusionsWork-related breastfeeding problems at 3 months postpartum were associated with low job satisfaction concurrently and at follow-up. Improving workplace breastfeeding accommodations could improve mothers' job satisfaction.

ObjectivesOnly a small number of studies have reported on the association of parental occupational exposure to benzene and risk of childhood and adolescent leukaemias. We examined associations with acute lymphoblastic leukaemia (ALL) in this population-based study in Denmark.MethodsBenzene was largely banned from Danish workplaces after 1975, thus this case-control study focused on the immediately prior years. Paediatric cancer cases (ResultsWe identified 217 employed case fathers and 169 employed case mothers, of which 22 (10.1%) and 11 (6.5%), respectively, were exposed to benzene (vs 6.7% and 2.9% of control fathers and mothers). Most exposed parents worked as machine or engine mechanics, or in the shoe industry. Maternal occupational exposure to benzene in pregnancy was related to increased risk of ALL in offspring (adjusted OR=2.28, 95% CI 1.17 to 4.41), while paternal preconceptional benzene exposure was not as strongly associated (adjusted OR=1.40, 95% CI 0.88 to 2.22).ConclusionsOur study supports an increased risk for ALL with parental occupational benzene exposure.

It is well established that high radon exposures increase the risk of lung cancer mortality. The effects of low occupational exposures and the factors that confound and modify this risk are not clear and are needed to inform current radiation protection of miners. The risk of lung cancer mortality at low radon exposures (

There is great concern regarding the adverse health implications of engineered nanoparticles. However, there are many circumstances where the production of incidental nanoparticles, i.e., nanoparticles unintentionally generated as a side product of some anthropogenic process, is of even greater concern. In this study, metal-based incidental nanoparticles were measured in two occupational settings: a machining center and a foundry. On-site characterization of substrate-deposited incidental nanoparticles using a field-portable X-ray fluorescence provided some insights into the chemical characteristics of these metal-containing particles. The same substrates were then used to carry out further off-site analysis including single-particle analysis using scanning electron microscopy and energy-dispersive X-ray spectroscopy. Between the two sites, there were similarities in the size and composition of the incidental nanoparticles as well as in the agglomeration and coagulation behavior of nanoparticles. In particular, incidental nanoparticles were identified in two forms: submicrometer fractal-like agglomerates from activities such as welding and supermicrometer particles with incidental nanoparticles coagulated to their surface, herein referenced as nanoparticle collectors. These agglomerates will affect deposition and transport inside the respiratory system of the respirable incidental nanoparticles and the corresponding health implications. The studies of incidental nanoparticles generated in occupational settings lay the groundwork on which occupational health and safety protocols should be built.

ObjectiveTo assess prenatal air toxics exposure and risk for childhood germ cell tumors (GCTs) by histological subtype (yolk sac tumor and teratoma).MethodsIn this case-control study, GCT cases less than 6 years (n = 243) identified from California Cancer Registry records were matched by birth year to cancer-free population controls (n = 147,100), 1984 to 2013. Routinely monitored air toxic exposures were linked to subjects' birth address. Logistic regression estimated GCT risks per interquartile range increase in exposure.ResultsPrenatal exposure to various highly-correlated, traffic-related air toxics during the second trimester increased GCT risk, particularly 1,3-butadiene (odds ratio [OR] = 1.51; 95% confidence interval [CI] = 1.01, 2.26) and meta/para-xylene (OR = 1.56; 95% CI = 1.10, 2.21). Analyses by subtype indicated elevated ORs for yolk sac tumors but not teratomas.ConclusionOur estimated ORs are consistent with positive associations between some prenatal traffic-related air toxics and GCT risk, notably yolk sac tumors.

Objectives Recent meta-analyses suggest a physical activity health paradox: high levels of occupational physical activity (OPA) increase cardiovascular disease (CVD) risk, while leisure-time physical activity (LTPA) decreases risk. However, studies of women and cerebrovascular disease are limited. This report examines physical activity effects on stroke and transient ischemic attack (TIA) among working women in the United States. Methods OPA history, health status, and lifestyle were assessed by baseline interviews of 31 270 employed Sister Study participants aged 35-74 years. OPA was assessed at six intensity levels (lowest: "mostly sitting"); the highest three were combined as "high intensity work." Independent OPA and LTPA effects on 6-year cerebrovascular disease incidence were estimated in adjusted Cox proportional hazard models. Results Stroke (N=441) and TIA (N=274) risk increased with more standing and higher intensity work at current and longest held job. Compared with mostly sitting, high intensity work at the current job increased TIA risk by 57% [hazard ratio (HR) 1.57, 95% confidence interval (CI) 1.04-2.38]. High intensity OPA at the longest held job increased risk for stroke by 44% (HR 1.44; 95% CI 1.08-1.93). Among women with CVD, sitting and standing equally, especially at the current job, increased risks up to two-fold (TIA HR 1.98, 95% CI 1.10-3.55) compared with mostly sitting at work. LTPA showed inverse associations. Conclusions Higher intensity levels of OPA increased stroke and TIA risks, while LTPA decreased risks; results corroborate the physical activity health paradox for women and cerebrovascular disease. More standing at work increased cerebrovascular disease risks, especially for women with CVD.

Objectives Shift work, such as alternating day and nights, causes chronobiologic disruptions which may cause an increase in hypertension risk. However, the relative contributions of the components of shift work ‒ such as shift type (eg, night work) and rotations (ie, switching of shift times; day to night) ‒ on this association are not clear. To address this question, we constructed novel definitions of night work and rotational work and assessed their associations with risk of incident hypertension. Methods A cohort of 2151 workers at eight aluminum manufacturing facilities previously studied for cardiovascular disease was followed from 2003 through 2013 for incident hypertension, as defined by ICD-9 insurance claims codes. Detailed time-registry data was used to classify each worker's history of rotational and night work. The associations between recent rotational work and night work in the last 12 months and incident hypertension were estimated using adjusted Cox proportional hazards models. Results Elevated hazard ratios (HR) were observed for all levels of recent night work (>0-5, >5-50, >50-95, >95-100%) compared with non-night workers, and among all levels of rotational work (10-20, >20-30, and >30%) compared with those working

ObjectivesIn a genome-wide association study, we discovered chromosome 12q15 (defined as rs73329476) as a silica-related pneumoconiosis susceptibility region. However, the causal variants in this region have not yet been reported.MethodsWe systematically screened eight potentially functional single-neucleotide polymorphism (SNPs) in the genes near rs73329476 (carboxypeptidase M (CPM) and cleavage and polyadenylation specific factor 6 (CPSF6)) in a case-control study including 177 cases with silicosis and 204 healthy controls, matched to cases with years of silica dust exposure. We evaluated the associations between these eight SNPs and the development of silicosis. Luciferase reporter gene assays were performed to test the effects of selected SNP on the activity of CPM in the promoter. In addition, a two-stage case-control study was performed to investigate the expression differences of the two genes in peripheral blood leucocytes from a total of 64 cases with silicosis and 64 healthy controls with similar years of silica dust exposure as the cases.ResultsWe found a strong association between the mutant rs12812500 G allele and the susceptibility of silicosis (OR=1.45, 95% CI 1.03 to 2.04, p=0.034), while luciferase reporter gene assays indicated that the mutant G allele of rs12812500 is strongly associated with increased luciferase levels compared with the wild-type C allele (p

ObjectiveTo determine whether early vascular aging may be present in flight attendants with remote in-cabin secondhand smoke (SHS) exposure.MethodsTwenty-six flight attendants with a history of in-cabin SHS exposure prior to the airline smoking bans were recruited. Pulse wave analysis, peripheral arterial tonometry, and brachial artery reactivity testing evaluated their arterial compliance and endothelial function.ResultsFlight attendants with remote in-cabin SHS exposure have normal blood pressure, pulse wave velocity, and reactive hyperemia index, but abnormal pulse pressure, augmentation index, flow-mediated dilation, and hyperemic mean flow ratio.ConclusionThese preliminary findings suggest that flight attendants with remote in-cabin SHS exposure have preclinical signs of accelerated vascular aging and raise new questions about the relationship between remote SHS exposure and vascular health.

ObjectiveHeterogeneity of depression experiences has led to suggestions that interventions focus on depression symptom combinations rather than depression severity alone. Our analyses explore the question, "What is the relationship between different combinations of depression symptoms and work productivity losses?"MethodsThese analyses use a population-based sample of 2219 working adults. Using the PHQ-8 items, cluster analysis methods were used to identify depression symptom clusters. The Work Limitations Questionnaire's four work productivity loss dimensions were regressed on the identified depression symptoms clusters.ResultsThe symptoms clusters of workers with mild to moderate depression had significant but similar work productivity losses. However, the symptom combinations within these clusters of workers varied.ConclusionTo create effective work accommodations, attention should focus on the combinations of depression symptoms and specific job characteristics rather than severity alone.

ObjectivesWe assessed the efficacy of trainings with Vietnamese nail salon owners and workers on knowledge and behaviors that could reduce exposures to toxic chemicals in nail products.MethodsWe trained Vietnamese salon owners in California (n = 77) who then trained their workers (n = 200) on best practices. In a cluster randomized controlled trial, we assessed the efficacy of the training on change in knowledge and self-reported behaviors. Data were collected from 2013 to 2016 and analyzed from 2016 to 2017.ResultsCompared to the control group, the intervention group had significantly greater increases in knowledge about: safer nail polishes [odds ratio (OR) 3.7 (95% confidence interval (CI) 1.9, 7.2)]; proper ventilation methods (OR 4.2; 95% CI 2.2, 8.1); recommended glove types (OR 3.4; 95% CI 1.9, 6.3); and recommended product handling and storage (OR 4.1; 95% CI 1.7, 9.9). The intervention also increased best practices: using safer nail polishes (OR 3.6; 95% CI 1.9, 6.8); reading product labels (OR 2.6; 95% CI 1.3, 5.0); and wearing long sleeves (OR 2.4; 95% CI 1.3, 4.2).ConclusionsThe owner-to-worker intervention with culturally and linguistically appropriate training for salon owners who then trained workers was effective in promoting knowledge and self-reported behaviors that can reduce workplace chemical exposures.

BackgroundChemicals in nail products have been linked to numerous health concerns.MethodsWe recruited Vietnamese-American nail salon owners and workers in California and randomized salons into an intervention or control group. Owners in the intervention group received training and then provided education to workers in their salons on best practices to reduce workplace chemical exposures. Methyl methacrylate (MMA), toluene, and total volatile organic compounds (TVOCs) were measured using personal air monitors worn by workers during the work-shift.ResultsWe enrolled 77 salons (37 intervention and 40 control) and 200 workers. There was no significant intervention effect between the two groups. However, MMA and TVOCs were higher for workers who used gel polish and acrylic nails as well as in busy salons.ConclusionsAlthough the intervention did not show reductions in chemical levels, identifying worker tasks and salon characteristics that predict chemical levels can inform future interventions to reduce exposures.

BACKGROUND:There is growing use of a job exposure matrix (JEM) to provide exposure estimates in studies of work-related musculoskeletal disorders; few studies have examined the validity of such estimates, nor did compare associations obtained with a JEM with those obtained using other exposures. OBJECTIVE:This study estimated upper extremity exposures using a JEM derived from a publicly available data set (Occupational Network, O*NET), and compared exposure-disease associations for incident carpal tunnel syndrome (CTS) with those obtained using observed physical exposure measures in a large prospective study. METHODS:2393 workers from several industries were followed for up to 2.8 years (5.5 person-years). Standard Occupational Classification (SOC) codes were assigned to the job at enrolment. SOC codes linked to physical exposures for forceful hand exertion and repetitive activities were extracted from O*NET. We used multivariable Cox proportional hazards regression models to describe exposure-disease associations for incident CTS for individually observed physical exposures and JEM exposures from O*NET. RESULTS:Both exposure methods found associations between incident CTS and exposures of force and repetition, with evidence of dose-response. Observed associations were similar across the two methods, with somewhat wider CIs for HRs calculated using the JEM method. CONCLUSION:Exposures estimated using a JEM provided similar exposure-disease associations for CTS when compared with associations obtained using the 'gold standard' method of individual observation. While JEMs have a number of limitations, in some studies they can provide useful exposure estimates in the absence of individual-level observed exposures.

IntroductionIndustry and occupation (I&O) information collected by cancer registries is useful for assessing associations among jobs and malignancies. However, systematic differences in I&O availability can bias findings.MethodsCodability by patient demographics, payor, identifying (casefinding) source, and cancer site was assessed using I&O text from first primaries diagnosed 2011-2012 and reported to California Cancer Registry. I&O were coded to a U.S. Census code or classified as blank/inadequate/unknown, retired, or not working for pay.ResultsIndustry was codable for 37% of cases; 50% had "unknown" and 9% "retired" instead of usual industry. Cases initially reported by hospitals, covered by preferred providers, or with known occupational etiology had highest codable industry; cases from private pathology laboratories, with Medicaid, or diagnosed in outpatient settings had least. Occupation results were similar.ConclusionsRecording usual I&O for retirees and improving linkages for reporting entities without patient access would improve I&O codability and research validity.

OBJECTIVES:There is growing evidence of an association between low-dose external γ-radiation and circulatory system diseases (CSDs), yet sparse data exist about an association with chronic internal uranium exposure and the role of non-radiation risk factors. We conducted a nested case-control study of French AREVA NC Pierrelatte nuclear workers employed between 1960 and 2005 to estimate CSD risks adjusting for major CSD risk factors (smoking, blood pressure, body mass index, total cholesterol and glycaemia) and external γ-radiation dose. METHODS:The study included 102 cases of death from CSD and 416 controls individually matched on age, gender, birth cohort and socio-professional status. Information on CSD risk factors was collected from occupational medical records. Organ-specific absorbed doses were estimated using biomonitoring data, taking into account exposure regime and uranium physicochemical properties. External γ-radiation was measured by individual dosimeter badges. Analysis was conducted with conditional logistic regression. RESULTS:Workers were exposed to very low radiation doses (mean γ-radiation dose 2 and lung uranium dose 1 mGy). A positive but imprecise association was observed (excess OR per mGy 0.2, 95% CI 0.004 to 0.5). Results obtained after adjustment suggest that uranium exposure might be an independent CSD risk factor. CONCLUSIONS:Our results suggest that a positive association might exist between internal uranium exposure and CSD mortality, not confounded by CSD risk factors. Future work should focus on numerous uncertainties associated with internal uranium dose estimation and on understanding biological pathway of CSD after protracted low-dose internal radiation exposure.