Description: Objectives Noise-induced hearing loss is one of the most serious occupational diseases worldwide. It is caused by interactions between environmental and genetic factors. The purpose of this study was to examine the association between the genetic susceptibility of the eye absent homolog 4 (EYA4) gene and the risk of developing noise-induced hearing loss in China. Methods A case–control association study was carried out with 326 hearing loss cases and 326 controls matched with age and duration of noise exposure, drawn from a cohort of steel workers. Five single nucleotide polymorphisms (SNPs) in the EYA4 were selected and genotyped. Logistic regression was performed to analyse the main effect of genotypes and interactions between genotypes and individual/environmental factors adjusted for confounding factors. Moreover, generalised multiple dimensionality reduction was applied to further detect interaction among the 5 selected SNPs. Results Analysis revealed that locus polymorphism of rs3813346 was associated with the risk of developing noise-induced hearing loss in the dominance model, the codominance model and the addictive model (p=0.004, 0.009 and 0.003, respectively). A significant interaction between rs9321402 and cumulative noise exposure was found (p=0.002). A significant main effect p value (p=0.006) was obtained in the high-level exposure group (cumulative noise exposure ≥98 dB(A)). Generalised multiple dimensionality reduction indicated that the combined interaction of the 2 loci—rs3813346 and rs9493627—significantly affected the incidence of noise-induced hearing loss. Conclusions The research suggests that EYA4 genetic variant and its interaction with noise levels may modify the susceptibility to develop noise-induced hearing loss in Chinese population.

Description: Background MRI has developed into one of the most important medical diagnostic imaging modalities, but it exposes staff to static magnetic fields (SMF) when present in the vicinity of the MR system, and to radiofrequency and switched gradient electromagnetic fields if they are present during image acquisition. We measured exposure to SMF and motion-induced time-varying magnetic fields (TVMF) in MRI staff in clinical practice in the UK to enable extensive assessment of personal exposure levels and variability, which enables comparison to other countries. Methods 8 MRI facilities across National Health Service sites in England, Wales and Scotland were included, and staff randomly selected during the days when measurements were performed were invited to wear a personal MRI-compatible dosimeter and keep a diary to record all procedures and tasks performed during the measured shift. Results 98 participants, primarily radiographers (71%) but also other healthcare staff, anaesthetists and other medical staff were included, resulting in 149 measurements. Average geometric mean peak SMF and TVMF exposures were 448 mT (range 20–2891) and 1083 mT/s (9–12 355 mT/s), and were highest for radiographers (GM=559 mT and GM=734 mT/s). Time-weighted exposures to SMF and TVMF (GM=16 mT (range 5–64) and GM=14 mT/s (range 9–105)) and exposed-time-weighted exposures to SMF and TVMF (GM=27 mT (range 11–89) and GM=17 mT/s (range 9–124)) were overall relative low—primarily because staff were not in the MRI suite for most of their shifts—and did not differ significantly between occupations. Conclusions These results are comparable to the few data available from the UK but they differ from recent data collected in the Netherlands, indicating that UK staff are exposed for shorter periods but to higher levels. These data indicate that exposure to SMF and TVMF from MRI scanners cannot be extrapolated across countries.

Description: Background The current knowledge on respiratory work disability is based on studies that used crude categories of exposure. This may lead to a loss of power, and does not provide sufficient information to allow targeted workplace interventions and follow-up of patients with respiratory symptoms. Objectives The aim of this study was to identify occupations and specific exposures associated with respiratory work disability. Methods In 2013, a self-administered questionnaire was mailed to a random sample of the general population, aged 16–50, in Telemark County, Norway. We defined respiratory work disability as a positive response to the survey question: ‘Have you ever had to change or leave your job because it affected your breathing?’ Occupational exposures were assessed using an asthma-specific job-exposure matrix, and comparison of risks was made for cases and a median of 50 controls per case. Results 247 workers had changed their work because of respiratory symptoms, accounting for 1.7% of the respondents ever employed. The ‘breath-taking jobs’ were cooks/chefs: adjusted OR 3.6 (95% CI 1.6 to 8.0); welders: 5.2 (2.0 to 14); gardeners: 4.5 (1.3 to 15); sheet metal workers: 5.4 (2.0 to 14); cleaners: 5.0 (2.2 to 11); hairdressers: 6.4 (2.5 to 17); and agricultural labourers: 7.4 (2.5 to 22). Job changes were also associated with a variety of occupational exposures, with some differences between men and women. Conclusions Self-report and job-exposure matrix data showed similar findings. For the occupations and exposures associated with job change, preventive measures should be implemented.

Description: Objectives Links between arrhythmias and particulate matter exposures have been found among sensitive populations. We examined the relationship between personal particulate matter ≤2.5 µm aerodynamic diameter (PM 2.5 ) exposures and ectopy in a panel study of healthy welders. Methods Simultaneous ambulatory ECG and personal PM 2.5 exposure monitoring with DustTrak Aerosol Monitor was performed on 72 males during work and non-work periods for 5–90 h (median 40 h). ECGs were summarised hourly for supraventricular ectopy (SVE) and ventricular ectopy (VE). PM 2.5 exposures both work and non-work periods were averaged hourly with lags from 0 to 7 h. Generalised linear mixed-effects models with a random participant intercept were used to examine the relationship between PM 2.5 exposure and the odds of SVE or VE. Sensitivity analyses were performed to assess whether relationships differed by work period and among current smokers. Results Participants had a mean (SD) age of 38 (11) years and were monitored over 2993 person-hours. The number of hourly ectopic events was highly skewed with mean (SD) of 14 (69) VE and 1 (4) SVE. We found marginally significant increases in VE with PM 2.5 exposures in the sixth and seventh hour lags, yet no association with SVE. For every 100 μg/m 3 increase in sixth hour lagged PM 2.5 , the adjusted OR (95% CI) for VE was 1.03 (1.00 to 1.05). Results persisted in work or non-work exposure periods and non-smokers had increased odds of VE associated with PM 2.5 as compared with smokers. Conclusions A small increase in the odds of VE with short-term PM 2.5 exposure was observed among relatively healthy men with environmental and occupational exposures.

Description: Background The association between lung cancer and occupational exposure to organic solvents is discussed. Since different solvents are often used simultaneously , it is difficult to assess the role of individual substances. Objectives The present study is focused on an in-depth investigation of the potential association between lung cancer risk and occupational exposure to a large group of organic solvents, taking into account the well-known risk factors for lung cancer, tobacco smoking and occupational exposure to asbestos. Methods We analysed data from the Investigation of occupational and environmental causes of respiratory cancers (ICARE) study, a large French population-based case–control study, set up between 2001 and 2007. A total of 2276 male cases and 2780 male controls were interviewed, and long-life occupational history was collected. In order to overcome the analytical difficulties created by multiple correlated exposures, we carried out a novel type of analysis based on Bayesian profile regression. Results After analysis with conventional logistic regression methods, none of the 11 solvents examined were associated with lung cancer risk. Through a profile regression approach, we did not observe any significant association between solvent exposure and lung cancer. However, we identified clusters at high risk that are related to occupations known to be at risk of developing lung cancer, such as painters. Conclusions Organic solvents do not appear to be substantial contributors to the occupational risk of lung cancer for the occupations known to be at risk.

Description: Objectives Many hairdressers leave their profession due to health problems, including occupational hand eczema, which has been associated with skin exposure to sensitising hair dye components such as paraphenylenediamine (PPD) and paratoluenediamine (PTD). Since the use of protective gloves is advised but without the short-term effect being known, our main goal was to attribute a significant biomarker reduction to adequate glove use, in a real work situation. Methods 11 hairdressers were studied over 2 weeks. In the first week, they worked as usual and (re)used their gloves. Thereafter, we intervened to improve glove use during the second week. In both weeks, workplace exposure data were collected through observations, and systemic exposure was quantified by biomonitoring of PPD and PTD. The effect of improved glove use and other exposure determinants was studied through mixed models analysis. Results We showed that improved glove use significantly reduced mean PTD concentrations from 24.1 before to 4.2 µg/g creatinine after the intervention (n=11, third day postshift). In addition, mean PTD concentrations increased during the first week (14 times elevated after three consecutive shifts), but not during the second week. For PPD, no effect of improved glove use and no accumulation effect were detected. Conclusions Our study is the first to deliver evidence for a significant reduction in systemic exposure to PTD through improved glove use. Disposable gloves should never be reused. PTD biomonitoring is shown to be a practical tool to quantify recent dermal exposure to oxidative hair dye components.

Description: Introduction The oxidative potential (OP) of particulate matter (PM) has been proposed as a health-relevant metric, but currently few epidemiological studies investigated associations of OP with health. Our main aim was to assess associations of long-term exposure to OP with respiratory health in children. Our second aim was to evaluate whether OP is more consistently associated with respiratory health than PM mass, PM composition or nitrogen dioxide (NO 2 ). Methods For 3701 participants of a prospective birth cohort, annual average concentrations of OP (assessed by spin resonance (OP ESR ) and dithiothreitol assay (OP DTT )), PM with an aerodynamic diameter of less than 2.5 µm (PM 2.5 ) mass, NO 2 , and PM 2.5 constituents at the home addresses at birth and at all follow-up addresses were estimated by land-use regression. Repeated questionnaire reports of asthma and hay fever until age 14 years, and measurements of allergic sensitisation, lung function and fractional exhaled nitric oxide at age 12 years were linked with air pollution concentrations. Results Asthma incidence, prevalence of asthma symptoms and rhinitis were positively associated with OP DTT (adjusted OR (95% CI) per IQR increase in exposure 1.10 (1.01 to 1.20), 1.08 (1.02 to 1.16), 1.15 (1.05 to 1.26), respectively). These associations persisted after adjustment for most co-pollutants. Forced expiratory volume in 1s and forced vital capacity were negatively associated with OP DTT . These associations were sensitive to adjustment for NO 2 . Respiratory health was not significantly associated with PM 2.5 mass and OP ESR . Conclusions Respiratory health was more strongly associated with OP DTT than with PM 2.5 mass; OP DTT associations with lung function, but not symptoms, were sensitive to adjustment for NO 2 .

Description: Objectives Several respirable hazards, including smoking and indoor air pollution from biomass, were suggested to increase the risk of tuberculosis. Few studies have been conducted on ambient air pollution and tuberculosis. We investigated the association between exposure to ambient air pollution and incidence of active tuberculosis. Methods We conducted a cohort study using 106 678 participants of a community-based screening service in Taiwan, 2005–2012. We estimated individual exposure to air pollution using data from the nearest air quality monitoring station and the road intensity within a 500 m buffer zone. The incidence of tuberculosis was ascertained from the national tuberculosis registry. Results After a median follow-up of 6.7 years, 418 cases of tuberculosis occurred. Exposure to fine particulate matter (PM 2.5 ) was associated with increased risk of active tuberculosis (adjusted HR: 1.39/10 μg/m 3 (95% CI 0.95 to 2.03)). In addition, traffic-related air pollution including nitrogen dioxide (adjusted HR: 1.33/10 ppb; 95% CI 1.04 to 1.70), nitrogen oxides (adjusted HR: 1.21/10 ppb; 95% CI 1.04 to 1.41) and carbon monoxide (adjusted HR: 1.89/ppm; 95% CI 0.78 to 4.58) was associated with tuberculosis risk. There was a non-significant trend between the length of major roads in the neighbourhood and culture-confirmed tuberculosis (adjusted HR: 1.04/km; 95% CI 0.995 to 1.09). Conclusions Our study revealed a possible link between ambient air pollution and risk of active tuberculosis. Since people from developing countries continue to be exposed to high levels of ambient air pollution and to experience high rates of tuberculosis, the impact of worsening air pollution on global tuberculosis control warrants further investigation.

Description: Background Asthma prevalence and acute exacerbations have been associated with endotoxin exposure. However, there are limited data on relations between acute asthma outcomes in children and personal exposure to endotoxin or whether this relation is modified by personal air pollution exposures. Methods We made repeated measurements of the fractional concentration of exhaled NO (F e NO ), forced expiratory volume in 1 s (FEV 1 ) and personal endotoxin exposures in patients with persistent asthma aged 9–18 years, each of whom was followed for 10 consecutive days in Riverside and Whittier, California. Endotoxin was measured in PM 2.5 , and simultaneously we measured personal exposure to air pollutants: NO 2 and PM 2.5 mass, elemental carbon and organic carbon. Endotoxin exposure–response relations and interactions between endotoxin and air pollutants were analysed with mixed models controlling for personal temperature, humidity and the 10-day period. Results Neither percent-predicted FEV 1 nor F e NO was associated with personal endotoxin overall; however, endotoxin was associated with FEV 1 among patients with average percent-predicted FEV 1 〈80%. When NO 2 was above its median, F e NO increased by 2.2% (95% CI –0.8% to 5.2%) for an interquartile increase in personal endotoxin, whereas F e NO was lower by –1.8% (95% CI –4% to 0.5%) when NO 2 was≤its median. However, this is out of 12 interaction tests between personal endotoxin and a binary air pollutant for each outcome (FEV 1 and F e NO ), and there were no interactions with any continuous-scaled pollutant. Conclusions Personal endotoxin exposure was not associated with acute daily changes in F e NO or FEV 1 in a cohort panel of schoolchildren with asthma, except for decreased FEV 1 among patients with more severe asthma (percent-predicted FEV 1 〈80%). There was limited evidence of effect modification of endotoxin by personal exposure to air pollution.

Description: Objectives Emergency medical services (EMS) clinicians are shift workers deployed in two-person teams. Extended shift duration, workplace fatigue, poor sleep and lack of familiarity with teammates are common in the EMS workforce and may contribute to workplace injury. We sought to examine the relationship between shift length and occupational injury while controlling for relevant shift work and teamwork factors. Methods We obtained 3 years of shift schedules and occupational injury and illness reports were from 14 large EMS agencies. We abstracted shift length and additional scheduling and team characteristics from shift schedules. We matched occupational injury and illness reports to shift records and used hierarchical logistic regression models to test the relationship between shift length and occupational injury and illness while controlling for teammate familiarity. Results The cohort contained 966 082 shifts, 4382 employees and 950 outcome reports. Risk of occupational injury and illness was lower for shifts ≤8 h in duration (RR 0.70; 95% CI 0.51 to 0.96) compared with shifts 〉8 and ≤12 h. Relative to shifts 〉8 and ≤12 h, risk of injury was 60% greater (RR 1.60; 95% CI 1.22 to 2.10) for employees that worked shifts 〉16 and ≤24 h. Conclusions Shift length is associated with increased risk of occupational injury and illness in this sample of EMS shift workers.