Description: Objectives Healthcare workers have high rates of low back pain (LBP) related to handling patients. A large chain of nursing homes experienced reduced biomechanical load, compensation claims and costs following implementation of a safe resident handling programme (SRHP). The aim of this study was to examine whether LBP similarly declined and whether it was associated with relevant self-reported occupational exposures or personal health factors. Methods Worker surveys were conducted on multiple occasions beginning with the week of first SRHP introduction (baseline). In each survey, the outcome was LBP during the prior 3 months with at least mild severity during the past week. Robust Poisson multivariable regression models were constructed to examine correlates of LBP cross-sectionally at 2 years (F3) and longitudinally at 5–6 years (F5) post-SRHP implementation among workers also in at least one prior survey. Results LBP prevalence declined minimally between baseline and F3. The prevalence was 37% at F3 and cumulative incidence to F5 was 22%. LBP prevalence at F3 was positively associated with combined physical exposures, psychological job demands and prior back injury, while frequent lift device usage and ‘intense’ aerobic exercise frequency were protective. At F5, the multivariable model included frequent lift usage at F3 (relative risk (RR) 0.39 (0.18 to 0.84)) and F5 work–family imbalance (RR=1.82 (1.12 to 2.98)). Conclusions In this observational study, resident lifting device usage predicted reduced LBP in nursing home workers. Other physical and psychosocial demands of nursing home work also contributed, while frequent intense aerobic exercise appeared to reduce LBP risk.

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: Objectives To examine the risk of death from leukaemia in relation to occupational chronic low-level external and internal radiation exposure in a cohort of 58 972 former German uranium miners with mortality follow-up from 1946 to 2013. Methods The red bone marrow (RBM) dose from low-linear energy transfer (LET) (mainly external -radiation) and high-LET (mainly radon gas) radiation was estimated based on a job-exposure matrix and biokinetic/dosimetric models. Linear excess relative risks (ERR) and 95% CIs were estimated via Poisson regression for chronic lymphatic leukaemia (CLL) and non-CLL. Results The mean cumulative low-LET and high-LET RBM doses among the 86% radiation-exposed workers were 48 and 9 mGy, respectively. There was a positive non-significant dose-response for mortality from non-CLL (n=120) in relation to low-LET (ERR/Gy=2.18; 95% CI –0.41 to 6.37) and high-LET radiation (ERR/Gy=16.65; 95% –1.13 to 46.75). A statistically significant excess was found for the subgroup chronic myeloid leukaemia (n=31) in relation to low-LET radiation (ERR/Gy=7.20; 95% CI 0.48 to 24.54) and the subgroup myeloid leukaemia (n=99) (ERR/Gy=26.02; 95% CI 2.55 to 68.99) for high-LET radiation. The ERR/Gy tended to be about five to ten times higher for high-LET versus low-LET radiation; however, the CIs largely overlapped. Results indicate no association of death from CLL (n=70) with either type of radiation. Conclusions Our findings indicate an increased risk of death for specific subtypes from non-CLL in relation to chronic low-LET and high-LET radiation, but no such relation for CLL.

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: Objective Among the aetiological factors of chronic low back pain (CLBP), occupational factors are often suspected, but their contribution remains to be ascertained. This study aimed to determine the impact of a wide range of occupational factors on the incidence and persistence of CLBP. Method From the VISAT (VIeillissement SAnté Travail) study, 1560 workers were examined at baseline and 5 years later. CLBP was defined as having low back pain or specific treatment for at least 6 months. Participants newly affected with CLBP and those with persistent CLBP at follow-up were distinguished. In addition to individual factors, a broad panel of occupational factors were analysed, covering employment, physical, organisational and psychosocial factors. Multivariate analyses were used to determine predictive factors of incidence and persistence of CLBP. Receiver operating characteristic (ROC) curves were performed to analyse the contribution of occupational factors. Results 22.6% of participants without any CLBP initially presented with CLBP 5 years later, while 53.7% of participants with CLBP at baseline had CLBP at the second collection. Carrying heavy loads, the lack of recognition of completed work and productivity-related income predicted a higher risk of incidence of CLBP. However, no significant association between occupational factors and the risk for persistence of CLBP was observed, while the risk was multiplied by two for history of depression and rheumatological events. ROC curves confirmed the significant contribution of occupational factors to incidence of CLBP. Conclusions Occupational factors played a pivotal role in the incidence of CLBP, while individual factors were the main determinants of persistence of CLBP.

Description: Objectives To examine the longitudinal relationship between incidence of diagnosed chronic disease and work status and hours worked. Methods A dynamic cohort approach was taken to construct our study sample using the Canadian National Population Health Survey. Participant inclusion criteria included being employed and without a chronic health condition in the survey cycle prior to diagnosis, and participation in consecutive surveys following diagnosis. Each respondent was matched with up to 5 respondents without a diagnosed health condition. The direct and indirect associations between chronic disease and work status and hours worked following diagnosis were examined using probit and linear regression path models. Separate models were developed for arthritis, back problems, diabetes, hypertension and heart disease. Results We identified 799 observations with a diagnosis of arthritis, 858 with back pain, 178 with diabetes, 569 with hypertension and 163 with heart disease, which met our selection criteria. An examination of total effects at time 1 and time 2 showed that, excluding hypertension, chronic disease diagnosis was related to work loss. The time 2 effect of chronic disease diagnosis on work loss was mediated through time 1 work status. With the exception of heart disease, an incident case of chronic disease was not related to changes in work hours among observations with continuous work participation. Conclusions Chronic disease can result in work loss following diagnosis. Research is required to understand how modifying occupational conditions may benefit employment immediately after diagnosis.

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 Casale Monferrato (north west Italy) is an area with an exceptionally high incidence of mesothelioma caused by asbestos contamination at work and in the general environment from the asbestos-cement Eternit plant that was operational until 1986. The purpose of this study was to quantify the association between pleural malignant mesothelioma (PMM) and asbestos cumulative exposure using individual assessment of environmental and domestic exposure, as well as of occupational exposure. Methods This population-based case-control study included cases of PMM diagnosed between January 2001 and June 2006 among residents in the Casale Monferrato Local Health Authority. Population controls were randomly sampled, matched by age and sex to cases. Cumulative exposure was estimated to account for the lifelong exposure history. Analyses were conducted using unconditional logistic regression models adjusting for gender, age at diagnosis and type of interview (direct or proxy respondents). Results 200 PMM cases of 223 eligible cases (89.7%) and 348 (63%) of 552 eligible controls accepted to be interviewed. ORs increased with cumulative exposure index (p〈0.0001) from 4.4 (CI 95% 1.7 to 11.3) (〈1 f/mL-years) to 62.1 (CI 95% 22.2 to 173.2) (≥10 f/mL-years). Among subjects never occupationally exposed, corresponding ORs were 3.8 (CI 95% 1.3 to 11.1) and 23.3 (CI 95% 2.9 to 186.9) (reference: background level of asbestos exposure). ORs of about 2, statistically significant, were observed for domestic exposure and for living in houses near buildings with large asbestos cement parts. Conclusions Risk of PMM increased with cumulative asbestos exposure and also in analyses limited to subjects non-occupationally exposed. Our results also provide indication of risk associated with common sources of environmental exposure and are highly relevant for the evaluation of residual risk after the cessation of asbestos industrial use.

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 determine risk for incident basal cell carcinoma from cumulative low-dose ionising radiation in the US radiologic technologist cohort. Methods We analysed 65 719 Caucasian technologists who were cancer-free at baseline (1983–1989 or 1994–1998) and answered a follow-up questionnaire (2003–2005). Absorbed radiation dose to the skin in mGy for estimated cumulative occupational radiation exposure was reconstructed for each technologist based on badge dose measurements, questionnaire-derived work history and protection practices, and literature information. Radiation-associated risk was assessed using Poisson regression and included adjustment for several demographic, lifestyle, host and sun exposure factors. Results Cumulative mean absorbed skin dose (to head/neck/arms) was 55.8 mGy (range 0–1735 mGy). For lifetime cumulative dose, we did not observe an excess radiation-related risk (excess relative risk/Gy=–0.01 (95% CI –0.43 to 0.52). However, we observed that basal cell carcinoma risk was increased for radiation dose received before age 30 (excess relative risk/Gy=0.59, 95% CI –0.11 to 1.42) and before 1960 (excess relative risk/Gy=2.92, 95% CI 1.39 to 4.45). Conclusions Basal cell carcinoma risk was unrelated to low-dose radiation exposure among radiologic technologists. Because of uncertainties in dosimetry and sensitivity to model specifications, both our null results and our findings of excess risk for dose received before age 30 and exposure before 1960 should be interpreted with caution.