Description: Objectives To explore whether work schedules and physically demanding work were associated with markers of ovarian reserve and response. Methods This analysis included women (n=473 and n=313 for ovarian reserve and ovarian response analysis, respectively) enrolled in a prospective cohort study of couples presenting to an academic fertility centre (2004–2015). Information on occupational factors was collected on a take-home questionnaire, and reproductive outcomes were abstracted from electronic medical records. Generalised linear models and generalised linear mixed models were used to evaluate the associations. Results Women who reported lifting or moving heavy objects at work had 1.0 fewer total oocytes (p=0.08), 1.4 fewer mature oocytes (p=0.007) and 0.7 fewer antral follicles (p=0.06) compared with women who reported never lifting or moving heavy objects at work. The inverse association between heavy lifting and oocyte yield was stronger in women 〉37 years and with a Body Mass Index ≥25 kg/m 2 . Women who worked evening/night/rotating shifts had 2.3 (p〈0.001) fewer mature oocytes, on average, compared with women who worked day-only shifts. None of the occupational exposures were associated with day 3 follicle-stimulating hormone or peak oestradiol levels. Conclusions Women working non-daytime shifts and those with physically demanding jobs had fewer mature oocytes retrieved after controlled ovarian hyperstimulation. Our results provide insight into possible mechanisms linking these occupational exposures with decreased fecundity.

Description: Objective The potential impact of environmental exposure to pyrethroid insecticides on child neurodevelopment has only just started to receive attention despite their widespread use. We investigated the associations between prenatal and childhood exposure to pyrethroid insecticides and behavioural skills in 6-year-olds. Methods The PELAGIE cohort enrolled 3421 pregnant women from Brittany, France between 2002 and 2006. 428 mothers were randomly selected for the study when their children turned 6, and 287 (67%) agreed to participate. Children's behaviour was assessed using the Strengths and Difficulties Questionnaire (SDQ). Three subscales (prosocial behaviour, internalising disorders and externalising disorders) were considered. Five pyrethroid metabolites were measured in maternal and child urine samples collected between 6 and 19 gestational weeks and at 6 years of age, respectively. Logistic regression and reverse-scale Cox regression models were used to estimate the associations between SDQ scores and urinary pyrethroid metabolite concentrations, adjusting for organophosphate metabolite concentrations and potential confounders. Results Increased prenatal cis -3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (DCCA) concentrations were associated with internalising difficulties (Cox p value=0.05). For childhood 3-phenoxybenzoic acid (PBA) concentrations, a positive association was observed with externalising difficulties (Cox p value=0.04) and high ORs were found for abnormal or borderline social behaviour (OR 2.93, 95% CI 1.27 to 6.78, and OR 1.91, 95% CI 0.80 to 4.57, for the intermediate and highest metabolite categories, respectively). High childhood trans -DCCA concentrations were associated with reduced externalising disorders (Cox p value=0.03). Conclusions The present study suggests that exposure to certain pyrethroids, at environmental levels, may negatively affect neurobehavioral development by 6 years of age.

Description: Objectives The use of genetically engineered enzymes in the synthesis of flavourings, fragrances and other applications has increased tremendously. There is, however, a paucity of data on sensitisation and/or allergy to the finished products. We aimed to review the use of genetically modified enzymes and the enormous challenges in human biomonitoring studies with suitable assays of specific IgE to a variety of modified enzyme proteins in occupational settings and measure specific IgE to modified enzymes in exposed workers. Methods Specific IgE antibodies against workplace-specific individual enzymes were measured by the specific fluorescence enzyme-labelled immunoassay in 813 exposed workers seen in cross-sectional surveys. Results Twenty-three per cent of all exposed workers showed type I sensitisation with IgE antibodies directed against respective workplace-specific enzymes. The highest sensitisation frequencies observed were for workers exposed enzymes derived from α-amylase (44%), followed by stainzyme (41%), pancreatinin (35%), savinase (31%), papain (31%), ovozyme (28%), phytase (16%), trypsin (15%) and lipase (4%). The highest individual antibody levels (up to 110 kU/L) were detected in workers exposed to phytase, xylanase and glucanase. In a subgroup comprising 134 workers, detailed clinical diagnostics confirmed work-related symptoms. There was a strong correlation (r=0.75, p〈0.0001) between the symptoms and antibody levels. Workers with work-related respiratory symptoms showed a higher prevalence for the presence of specific IgE antibodies against workplace-specific enzymes than asymptomatic exposed workers (likelihood ratio 2.32, sensitivity 0.92, specificity 0.6). Conclusions Our data confirm the previous findings showing that genetically engineered enzymes are potent allergens eliciting immediate-type sensitisation. Owing to lack of commercial diagnostic tests, few of those exposed receive regular surveillance including biomonitoring with relevant specific IgE assays.

Description: Objectives To describe the health burden among Fire Department of the City of New York (FDNY) emergency medical service (EMS) workers and examine its association with work at the World Trade Center (WTC) disaster site. Methods In this observational cohort study, we used FDNY physician diagnoses to estimate the cumulative incidence of physical health conditions including rhinosinusitis, gastroesophageal reflux disease (GERD), obstructive airways disease (OAD) and cancer among EMS workers and demographically similar firefighters who were active on 11 September 2001 (9/11). Validated screening instruments were used to estimate the prevalence of probable post-traumatic stress disorder (PTSD), probable depression and probable harmful alcohol use. We also analysed the association between health conditions and WTC-exposure. Results Among 2281 EMS workers, the 12-year post-9/11 cumulative incidence (11 September 2001 to 31 December 2013) of rhinosinusitis was 10.6%; GERD 12.1%; OAD 11.8%; cancer 3.1%. The prevalence of probable PTSD up to 12 years after exposure was 7%; probable depression 16.7%; and probable harmful alcohol use 3%. Compared with unexposed, EMS workers who arrived earliest at the site had higher adjusted relative risks (aRR) for most conditions, including rhinosinusitis (aRR=3.7; 95% CI 2.2 to 6.0); GERD (aRR=3.8; 95% CI 2.4 to 6.1); OAD (aRR=2.4: 95% CI 1.7 to 3.6); probable PTSD (aRR=7.0; 95% CI 3.6 to 13.5); and, probable depression (aRR=2.3; 95% CI 1.6 to 3.1). Conclusions In this 12-year study, we documented a high burden of health conditions associated with WTC-exposure among FDNY EMS workers. These findings underscore the importance of continued monitoring and treatment of this workforce.

Description: Objective To report the effects of bleach use at home on the frequency of infections in 9102 school-age children participating in the HITEA project. Methods Parents of pupils aged 6–12 years from schools in Barcelona province (Spain), Utrecht province (the Netherlands) and Eastern and Central Finland were administered a questionnaire including questions on the frequency of infections (influenza, tonsillitis, sinusitis, otitis, bronchitis and pneumonia) in the past 12 months and bleach use at home. We developed multivariable mixed-effects multilogistic regression models to obtain relative risk ratios (RRR) and their 95% CI per country, and combined the RRR using random-effects meta-analyses. Results Bleach use was common in Spain (72%, n=1945) and uncommon in Finland (7%, n=279). Overall, the prevalence of infections (recurrent or once) was higher among children of bleach users. Significant combined associations were shown for influenza only once (RRR=1.20, 95% CI 1.04 to 1.38), recurrent tonsillitis (RRR=1.35, 95% CI 1.07 to 1.71) and any infection (RRR=1.18, 95% CI 1.01 to 1.38). Conclusions Passive exposure to cleaning bleach in the home may have adverse effects on school-age children's health by increasing the risk of respiratory and other infections. The high frequency of use of disinfecting irritant cleaning products may be of public health concern, also when exposure occurs during childhood.

Description: Objectives Limited evidence suggests adverse effects of traffic noise exposure on the metabolic system. This study investigates the association between road traffic noise and obesity markers as well as the role of combined exposure to multiple sources of traffic noise. Methods In a cross-sectional study performed in 2002–2006, we assessed exposure to noise from road traffic, railways and aircraft at the residences of 5075 Swedish men and women, primarily from suburban and semirural areas of Stockholm County. A detailed questionnaire and medical examination provided information on markers of obesity and potential confounders. Multiple linear and logistic regression models were used to assess associations between traffic noise and body mass index (BMI), waist circumference and waist–hip ratio using WHO definitions of obesity. Results Road traffic noise was significantly related to waist circumference with a 0.21 cm (95% CI 0.01 to 0.41) increase per 5 dB(A) rise in L den . The OR for central obesity among those exposed to road traffic noise ≥45 dB(A) was 1.18 (95% CI 1.03 to 1.34) in comparison to those exposed below this level. Similar results were seen for waist–hip ratio (OR 1.29; 95% CI 1.14 to 1.45) but not for BMI (OR 0.89; 95% CI 0.76 to 1.04). Central obesity was also associated with exposure to railway and aircraft noise, and a particularly high risk was seen for combined exposure to all three sources of traffic noise (OR 1.95; 95% CI 1.24 to 3.05). Conclusions Our results suggest that traffic noise exposure can increase the risk of central obesity. Combined exposure to different sources of traffic noise may convey a particularly high risk.

Description: Objectives To identify diagnostic, patient/employee, general practitioner (GP) and practice factors associated with length of certified sickness episodes. Methods Twelve-month collection of fit note data at 68 general practices in eight regions of England, Wales and Scotland between 2011 and 2013. Secondary analysis of sick note data collected at seven general practices in 2001/2002. All employed patients receiving at least one fit note at practices within the collection period were included in the study. Main study outcomes were certified sickness episodes lasting longer than 3, 6 and 12 weeks. Results The data from seven practices contributing in 2013, and a decade previously, suggest that periods of long-term sickness absence may be falling overall (risk 〉12 weeks absence, OR=0.65) but the proportion of mild–moderate mental disorder-related (M-MMD) episodes is rising (26% to 38%). Over 32% (8064/25 078) of fit notes issued to working patients in the 68 practices were for a M-MMD. A total of 13 994 patient sickness ‘episodes’ were identified. Diagnostic category of episode, male patients, older patient age and higher social deprivation were significantly associated with the 〉3 week, 〉6 week and long-term (〉12 week) outcomes, and GP partner status with the long-term outcome only. Conclusions In the context of a rapidly changing legislative environment, the study used the largest sickness certification database constructed in the UK to enhance the evidence base relating to factors contributing to long-term work incapacity.

Description: Objectives Shift work, like chronic jet lag, is known to disrupt workers’ normal circadian rhythms and social life, and to be associated with increased health problems (eg, ulcers, cardiovascular disease, metabolic syndrome, breast cancer, reproductive difficulties) and with acute effects on safety and productivity. However, very little is known about the long-term consequences of shift work on cognitive abilities. The aim of this study was to assess the chronicity and reversibility of the effects of shift work on cognition. Methods We conducted a prospective cohort study of 3232 employed and retired workers (participation rate: 76%) who were 32, 42, 52 and 62 years old at the time of the first measurement (t1, 1996), and who were seen again 5 (t2) and 10 (t3) years later. 1484 of them had shift work experience at baseline (current or past) and 1635 had not. The main outcome measures were tests of speed and memory, assessed at all three measurement times. Results Shift work was associated with impaired cognition. The association was stronger for exposure durations exceeding 10 years (dose effect; cognitive loss equivalent to 6.5 years of age-related decline in the current cohort). The recovery of cognitive functioning after having left shift work took at least 5 years (reversibility). Conclusions Shift work chronically impairs cognition, with potentially important safety consequences not only for the individuals concerned, but also for society.

Description: Objectives An ‘information gap’ has been identified regarding the effects of chronic disease on occupational injury risk. We investigated the association of ischaemic heart disease, hypertension, diabetes, depression and asthma with acute occupational injury in a cohort of manufacturing workers from 1 January 1997 through 31 December 2007. Methods We used administrative data on real-time injury, medical claims, workplace characteristics and demographics to examine this association. We employed a piecewise exponential model within an Andersen–Gill framework with a frailty term at the employee level to account for inclusion of multiple injuries for each employee, random effects at the employee level due to correlation among jobs held by an employee, and experience on the job as a covariate. Results One-third of employees had at least one of the diseases during the study period. After adjusting for potential confounders, presence of these diseases was associated with increased hazard of injury: heart disease (HR 1.23, 95% CI 1.11 to 1.36), diabetes (HR 1.17, 95% CI 1.08 to 1.27), depression (HR 1.25, 95% CI 1.12 to 1.38) and asthma (HR 1.14, 95% CI 1.02 to 1.287). Hypertension was not significantly associated with hazard of injury. Associations of chronic disease with injury risk were less evident for more serious reportable injuries; only depression and a summary health metric derived from claims remained significantly positive in this subset. Conclusions Our results suggest that chronic heart disease, diabetes and depression confer an increased risk for acute occupational injury.

Description: Objectives To quantify the variation in rates of absence due to musculoskeletal pain across 47 occupational groups (mostly nurses and office workers) from 18 countries, and to explore personal and group-level risk factors that might explain observed differences. Methods A standardised questionnaire was used to obtain information about musculoskeletal pain, sickness absence and possible risk factors in a cross-sectional survey of 12 416 workers (92–1017 per occupational group). Additionally, group-level data on socioeconomic variables, such as sick pay and unemployment rates, were assembled by members of the study team in each country. Associations of sickness absence with risk factors were examined by Poisson regression. Results Overall, there were more than 30-fold differences between occupational groups in the 12-month prevalence of prolonged musculoskeletal sickness absence, and even among office workers carrying out similar occupational tasks, the variation was more than tenfold. Personal risk factors included older age, lower educational level, tendency to somatise, physical loading at work and prolonged absence for non-musculoskeletal illness. However, these explained little of the variation between occupational groups. After adjustment for individual characteristics, prolonged musculoskeletal sickness absence was more frequent in groups with greater time pressure at work, lower job control and more adverse beliefs about the work-relatedness of musculoskeletal disorders. Conclusions Musculoskeletal sickness absence might be reduced by eliminating excessive time pressures in work, maximising employees’ responsibility and control and providing flexibility of duties for those with disabling symptoms. Care should be taken not to overstate work as a cause of musculoskeletal injury.