Description: Objectives Although many studies have investigated the association between trichloroethylene (TCE) exposure and non-Hodgkin’s lymphoma (NHL), less is known about other chlorinated solvents. We extended our previous analysis of occupational TCE exposure in a multicentre population-based case-control study of NHL to investigate associations with five additional chlorinated solvents: 1,1,1,-trichloroethane, carbon tetrachloride, chloroform, methylene chloride and perchloroethylene. Methods Cases (n=1189) and controls (n=982) provided detailed information on their occupational histories and workplace exposure to chlorinated solvents for selected occupations using job-specific interview modules. An industrial hygienist used this information and a review of the literature to assess occupational exposure to chlorinated solvents. We computed ORs and 95% CIs for different exposure metrics, with the unexposed group as the referent. We also computed ORs by NHL subtype. Results High cumulative hours exposed to carbon tetrachloride was associated with NHL (〉520 hours: OR 1.9; 95% CI 1.0 to 3.6; P trend =0.04). This association remained after restricting to jobs with high-intensity exposure (OR 2.0; 95% CI 1.1 to 3.8; P=0.03) and ≥90% exposure probability (OR 2.1; 95% CI 1.0 to 4.3; P=0.03), adjusting for TCE (OR 2.1; 95% CI 1.0– to 4.1; P=0.04) and incorporating a 15-year lag (OR 1.9; 95% CI 1.0 to 3.6; P=0.06). The other evaluated chlorinated solvents were not associated with NHL. Conclusions This is the first study using high-quality quantitative exposure assessment methods to identify a statistically significant elevated association between occupational exposure to carbon tetrachloride and NHL. Our findings, although limited by a small number of exposed cases, offer evidence that carbon tetrachloride may be a lymphomagen.

Description: Background Studies have linked ambient air pollution to chronic obstructive pulmonary disease (COPD) healthcare encounters. However, the association between air quality and rescue medication use is unknown. Objectives We assessed the role of air pollution exposure for increased short-acting beta-2-agonist (SABA) use in patients with COPD through use of remote monitoring technology. Methods Participants received a portable electronic inhaler sensor to record the date, time and location for SABA use over a 3-month period. Ambient air pollution data and meteorological data were collected from a centrally located federal monitoring station. Mixed-effects Poisson regression was used to examine the association of daily inhaler use with pollutant levels. Four criteria pollutants (PM 2.5 , PM 10 , O 3 and NO 2 ), two particulate matter species (elemental carbon (EC) and organic carbon), estimated coarse fraction of PM 10 (PM 10–2.5 ) and four multipollutant air quality measures were each examined separately, adjusting for covariates that passed a false discovery rate (FDR) screening. Results We enrolled 35 patients with COPD (94.3% male and mean age: 66.5±8.5) with a mean forced expiratory volume in 1 s (FEV 1 ) % predicted of 44.9+17.2. Participants had a median of 92 observation days (range 52–109). Participants’ average SABA inhaler use ranged from 0.4 to 13.1 puffs/day (median 2.8). Controlling for supplemental oxygen use, long-acting anticholinergic use, modified Medical Research Council Dyspnoea Scale and influenza season, an IQR increase in PM 10 concentration (8.0 µg/m 3 ) was associated with a 6.6% increase in daily puffs (95% CI 3.5% to 9.9%; FDR 〈0.001). NO 2 and EC concentration were also significantly associated with inhaler use (3.9% and 2.9% per IQR increase, respectively). Conclusions Exposure to increased ambient air pollution were associated with a significant increase in SABA use for patients with COPD residing in a low-pollution area.

Description: Objective Research indicates that shiftwork may be associated with increased risks of adverse health outcomes, including some cancers. However, the evidence of an association between shiftwork and colorectal cancer risk is limited and inconclusive. Further, while several possible pathways through which shiftwork might result in cancer have been proposed, few studies have taken these factors into account. We investigated the association between two types of shiftwork (graveyard shiftwork and early-morning shiftwork) and six mechanistic shiftwork variables (including light at night and phase shift) and the risk of colorectal cancer among females in an Australian population-based case–control study. Graveyard shiftwork was the primary exposure of interest. Methods Participants (350 cases and 410 controls) completed a lifetime occupational history, and exposure to each of the eight shiftwork variables was assigned to participants through a job exposure matrix. We used logistic regression to calculate odds ratios (OR) and corresponding 95% confidence intervals (CI) for the association between different shiftwork variables and the risk of colorectal cancer, adjusting for potential demographic, lifestyle and medical confounders. Results Working in an occupation involving long-term exposure (〉7.5 years) to graveyard shiftwork was not associated with colorectal cancer risk (adjusted OR 0.95, 95% CI 0.57 to 1.58). Similarly, no increased risks of colorectal cancer were seen for any of the other seven shiftwork variables examined. Conclusions No evidence of an increased risk of colorectal cancer among females who had worked in occupations involving shiftwork was observed in this study.

Description: Objectives To investigate the association between occupational exposure to disinfectants/antiseptics used for hand hygiene and asthma control in nurses. Methods In 2014, we invited female nurses with asthma drawn from the Nurses’ Health Study II to complete two supplemental questionnaires on their occupation and asthma (cross-sectional study, response rate: 80%). Among 4055 nurses (mean age: 59 years) with physician-diagnosed asthma and asthma medication use in the past year, we examined asthma control, as defined by the Asthma Control Test (ACT). Nurses were asked about the daily frequency of hand hygiene tasks: ‘wash/scrub hands with disinfectants/hand sanitizers’ (hand hygiene) and ‘wash/scrub arms with disinfecting products’ (surrogate of surgical hand/arm antisepsis). Analyses were adjusted for age, race, ethnicity, smoking status and body mass index. Results Nurses with partly controlled asthma (ACT: 20–24, 50%) and poorly controlled asthma (ACT ≤19, 18%) were compared with nurses with controlled asthma (ACT=25, 32%). In separate models, both hand and arm hygiene were associated with poorly controlled asthma. After mutual adjustment, only arm hygiene was associated with poorly controlled asthma: OR (95% CI) for 〈1 time/day, 1.38 (1.06 to 1.80); ≥1 time/day, 1.96 (1.52 to 2.51), versus never. We observed a consistent dose–response relationship between frequency of arm hygiene tasks (never to 〉10 times/day) and poor asthma control. Associations persisted after further adjustment for surfaces/instruments disinfection tasks. Conclusions Frequency of hand/arm hygiene tasks in nurses was associated with poor asthma control. The results suggest an adverse effect of products used for surgical hand/arm antisepsis. This potential new occupational risk factor for asthma warrants further study.

Description: Objectives There is growing evidence of an association between low-dose external -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 -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 -radiation was measured by individual dosimeter badges. Analysis was conducted with conditional logistic regression. Results Workers were exposed to very low radiation doses (mean -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.

Description: Objectives To examine cancer incidence among Danish firefighters using several employment-related exposure subgroups. Methods A historical cohort of 9061 male Danish firefighters was established from collected personnel and membership records from employers and trade unions. Using the unique Danish personal identification number, information on additional previous employment, cancer and vital status was linked to members of the cohort from the Supplementary Pension Fund Register, the Danish Cancer Registry and the Danish Civil Registration System. SIRs were calculated for specific cancer types using rates for the general population, a sample of the working population and military employees, respectively. Results Compared with the selected reference groups, the overall observed incidence of cancer among the firefighters was at level with the expected (SIR 1.02, 95% CI 0.96 to 1.09 vs the general population). The SIR for colon cancer was consistently significantly reduced, while the slight excess seen for melanoma of the skin, prostate and testicular cancer compared with the general population was not reproduced using the military as reference. Conclusions Previous associations with melanoma of the skin, prostate and testicular cancer are supported by our main results. However, the increase in incidence of these cancers is not reproduced using the military as reference. Similarities in cancer profile for the firefighters and the military point to shared risk factors in either lifestyle or work environment.

Description: Objectives The French nuclear worker cohort allows for the assessment of cancer risk associated with occupational radiation exposure, but workers are also exposed to medical and environmental radiation which can be of the same order of magnitude. This study aims to examine the impact of non-occupational radiation exposures on the dose-risk analysis between occupational radiation exposure and cancer mortality. Methods The cohort included workers employed before 1995 for at least one year by CEA, AREVA NC or EDF and badge-monitored for external radiation exposure. Monitoring results were used to calculate occupational individual doses. Scenarios of work-related X-ray and environmental exposures were simulated. Poisson regression was used to quantify associations between occupational exposure and cancer mortality adjusting for non-occupational radiation exposure. Results The mean cumulative dose of external occupational radiation was 18.4 mSv among 59 004 workers. Depending on the hypotheses made, the mean cumulative work-related X-ray dose varied between 3.1 and 9.2 mSv and the mean cumulative environmental dose was around 130 mSv. The unadjusted excess relative rate of cancer per Sievert (ERR/Sv) was 0.34 (90% CI –0.44 to 1.24). Adjusting for environmental radiation exposure did not substantially modify this risk coefficient, but it was attenuated by medical exposure (ERR/Sv point estimate between 0.15 and 0.23). Conclusions Occupational radiation risk estimates were lower when adjusted for work-related X-ray exposures. Environmental exposures had a very slight impact on the occupational exposure risk estimates. In any scenario of non-occupational exposure considered, a positive but insignificant excess cancer risk associated with occupational exposure was observed.

Description: Objectives Estimates of association between exposures and diseases are often distorted by error in exposure classification. When the validity of exposure assessment is known, this can be used to adjust these estimates. When exposure is assessed by experts, even if validity is not known, we sometimes have information about interrater reliability. We present a Bayesian method for translating the knowledge of interrater reliability, which is often available, into knowledge about validity, which is often needed but not directly available, and applying this to correct odds ratios (OR). Methods The method allows for inclusion of observed potential confounders in the analysis, as is common in regression-based control for confounding. Our method uses a novel type of prior on sensitivity and specificity. The approach is illustrated with data from a case-control study of lung cancer risk and occupational exposure to diesel engine emissions, in which exposure assessment was made by detailed job history interviews with study subjects followed by expert judgement. Results Using interrater agreement measured by kappas (), we estimate sensitivity and specificity of exposure assessment and derive misclassification-corrected confounder-adjusted OR. Misclassification-corrected and confounder-adjusted OR obtained with the most defensible prior had a posterior distribution centre of 1.6 with 95% credible interval (Crl) 1.1 to 2.6. This was on average greater in magnitude than frequentist point estimate of 1.3 (95% Crl 1.0 to 1.7). Conclusions The method yields insights into the degree of exposure misclassification and appears to reduce attenuation bias due to misclassification of exposure while the estimated uncertainty increased.

Description: Objectives The main objective was to determine whether sleep duration on work shifts mediates the relationship between a current alternating day and night shift work schedule and metabolic syndrome among female hospital employees. The secondary objective was to assess whether cumulative lifetime shift work exposure was associated with metabolic syndrome. Methods In this cross-sectional study of 294 female hospital employees, sleep duration was measured with the ActiGraph GT3X+. Shift work status was determined through self-report. Investigation of the total, direct and indirect effects between shift work, sleep duration on work shifts and metabolic syndrome was conducted using regression path analysis. Logistic regression was used to determine the association between cumulative shift work exposure and metabolic syndrome. Results Shift work is strongly associated with metabolic syndrome (OR Total =2.72, 95% CI 1.38 to 5.36), and the relationship is attenuated when work shift sleep duration is added to the model (OR Direct =1.18, 95% CI 0.49 to 2.89). Sleep duration is an important intermediate between shift work and metabolic syndrome (OR Indirect =2.25, 95% CI 1.27 to 4.26). Cumulative shift work exposure is not associated with metabolic syndrome in this population. Conclusions Sleep duration mediates the association between a current alternating day–night shift work pattern and metabolic syndrome.

Description: Background The prevalence of pleural abnormalities in the general population is an epidemiologically important index of asbestos exposure, which has not been investigated since a radiography-based study in 1980. Methods We examined 2633 chest CT scans (mean 59.2 years, 50% female) from the Framingham Heart Study (FHS) for the presence and image characteristics of pleural plaques and diffuse pleural thickening. Demographics and pulmonary function were stratified by the presence of pleural abnormalities in association with interstitial lung abnormalities. Results Pleural abnormalities were present in 1.5% (95% CI 1.1% to 2.1%). Pleural lesions were most commonly bilateral (90.0%), multiple (77.5%), calcified (97.5%) and commonly involved posterior (lower: 92.5%, middle: 87.5%), anterior (upper: 77.5%, middle: 77.5%) and diaphragmatic areas (72.5%). Participants with pleural abnormalities were significantly older (75.7 years, p 〈0.0001), male (92.5%, p 〈0.0001), former or current smokers (80.0%, p 〈0.001) with higher pack-years (33.3, p 〈0.0001). No significant reduction was noted in pulmonary function measures (p=0.07–0.94) when adjusted for the associated covariates, likely due to small number of cases with pleural abnormalities. Information about prior history of asbestos exposure and occupation was not available. Conclusions Pleural plaques and diffuse pleural thickening are present on CT in 1.5% of the FHS cohort. The current prevalence of the pleural abnormalities is smaller than that reported in the previous population-based study using chest radiography, likely representing lower asbestos exposure in recent decades. The posterior portion of the pleura is most frequently involved but the anterior portion is also commonly involved.