Estimated daily intake and cumulative risk assessment of organophosphate esters and associations with DNA damage among e-waste workers in Hong Kong.

Organophosphate esters (OPEs) are extensively used as additives in various products, including electronic equipment, which becomes e-waste when obsolete. Nevertheless, no study has evaluated OPEs exposure levels and the related health risks among e-waste workers in Hong Kong. Therefore, 201 first-spot morning urine samples were collected from 101 e-waste workers and 100 office workers to compare eight urinary OPE metabolites (mOPEs) levels in these groups. The concentrations of six mOPEs were similar in e-waste workers and office workers, except for significantly higher levels of diphenyl phosphate (DPHP) in e-waste workers and bis(1-chloro-2propyl) phosphate (BCIPP) in office workers. Spearman correlation analysis showed that most non-chlorinated mOPEs were correlated with each other in e-waste workers (i.e., nine out of ten pairs, including di-p-cresyl phosphate (DpCP) and di-o-cresyl phosphate (DoCP), DpCP and bis(2-butoxyethyl) phosphate (BBOEP), DpCP and DPHP, DpCP and dibutyl phosphate (DBP), DoCP and BBOEP, DoCP and DPHP, DoCP and DBP, BBOEP and DPHP, DPHP and DBP), indicating that handling e-waste could be the exposure source of specific OPEs. The median values of estimated daily intake (EDI) and hazard quotient (HQ) suggested that the health risks from OPEs exposures were under the recommended thresholds. However, linear regression models, Quantile g-computation, and Bayesian kernel machine regression found that urinary mOPEs elevated 8-hydroxy-2-deoxyguanosine (8-OhdG) levels individually or as a mixture, in which DPHP contributed prominently. In conclusion, although e-waste might not elevate the internal OPEs levels among the participating Hong Kong e-waste workers, attention should be paid to the potential DNA damage stimulated by OPEs under the currently recommended thresholds.

A scoping review to identify strategies that work to prevent four important occupational diseases.

BACKGROUND: Despite being largely preventable, many occupational diseases continue to be highly prevalent and extremely costly. Effective strategies are required to reduce their human, economic, and social impacts. METHODS: To better understand which approaches are most likely to lead to progress in preventing noise-related hearing loss, occupational contact dermatitis, occupational cancers, and occupational asthma, we undertook a scoping review and consulted with a number of key informants. RESULTS: We examined a total of 404 articles and found that various types of interventions are reported to contribute to occupational disease prevention but each has its limitations and each is often insufficient on its own. Our principal findings included: legislation and regulations can be an effective means of primary prevention, but their impact depends on both the nature of the regulations and the degree of enforcement; measures across the hierarchy of controls can reduce the risk of some of these diseases and reduce exposures; monitoring, surveillance, and screening are effective prevention tools and for evaluating the impact of legislative/policy change; the effect of education and training is context-dependent and influenced by the manner of delivery; and, multifaceted interventions are often more effective than ones consisting of a single activity. CONCLUSIONS: This scoping review identifies occupational disease prevention strategies worthy of further exploration by decisionmakers and stakeholders and of future systematic evaluation by researchers. It also identified important gaps, including a lack of studies of precarious workers and the need for more studies that rigorously evaluate the effectiveness of interventions.

Adult Asthma among Workers in Ontario. Results from the Occupational Disease Surveillance System.

Rationale: Given that approximately 15% of new-onset adult asthma cases originate because of exposures in the workplace, there is a need for systematic and ongoing monitoring of risk among workers. Objectives: To characterize the risk of new-onset adult asthma among workers in Ontario. Methods: We used 575,379 provincial accepted time-loss workers' compensation claimants data linked to physician billing data. Workers aged 15 to 65 years with a nonasthma compensation claim between January 1, 2002, and December 31, 2013, were eligible for inclusion. Cohort entry corresponded to the date of the claim. The case definition required two or more records for asthma within a 12-month period, within a 3-year time window after cohort entry. A 3-year washout period preceding cohort entry was used to exclude prevalent cases. Workers at risk of new-onset adult asthma were followed from cohort entry date to date of diagnosis, emigration, age 65 years, death, or end of study period. Cox regression models were used to generate birth year- and sex-adjusted hazard ratios (HRs) by occupation, industry, and exposures identified using a job exposure matrix. Sex-stratified risk estimates were also generated. Results: Increased risks were detected among well-recognized groups, including bakers (HR, 1.60; 95% confidence interval [CI], 1.22-2.09) and painters and decorators (HR, 1.67; 95% CI, 1.23-2.28). In the job exposure matrix analysis, flour and isocyanates were associated with increased risk of asthma. Concrete finishers (HR, 1.93; 95% CI, 1.12-3.32) and shipping and receiving clerks (HR, 1.21; 95% CI, 1.03-1.43) also showed elevated risk, whereas results varied across woodworker groups. Decreased risks were detected for nursing and farming groups. Conclusions: This practical data linkage approach was successful for examining associations across hundreds of jobs. Unexpected and previously unrecognized findings deserve further investigation and emphasize the importance of an ongoing system to guide research as well as prevention.

Using health insurance administrative data to explore patch testing utilization in Ontario, Canada-An untapped resource.

BACKGROUND: Patch testing is the key diagnostic test for diagnosing allergic contact dermatitis, but there is limited information on the use of patch testing at the population level. OBJECTIVES: To utilize Ontario Health Insurance Plan (OHIP) data to analyse trends in the rate of patch testing in Ontario. METHODS: Patch testing billing data submitted to the OHIP between 1992 and 2014 were analysed. Two patch test billing codes were investigated: one for work-related testing (G198), and one for non-work-related testing (G206). Rates of patch testing overall were calculated, and trends over time were described. RESULTS: There were 51 576 patch test billings: 48 416 non-work-related and 3160 work-related. The annual rate of non-work-related patch testing (G206) ranged from 11.9 per 100 000 people to 25.9 per 100 000 people, increasing over time. The rate of work-related patch testing (G198) ranged from 0.17 to 2.32 per 1 000 000 people, and was relatively stable. The overall distribution of billing by specialty was 70% dermatology, 19% other medical subspecialties, and 10% paediatrics and family medicine. CONCLUSIONS: Administrative health data can contribute to a more complete understanding of patch test utilization at the population level and, over time, can be used to track patch testing practices.

Burden of lung cancer attributable to occupational diesel engine exhaust exposure in Canada.

OBJECTIVE: To estimate the population attributable fraction (PAF) and number of incident and fatal lung cancers in Canada from occupational exposure to diesel engine exhaust (DEE). METHODS: DEE exposure prevalence and level estimates were used with Canadian Census and Labour Force Survey data to model the exposed population across the risk exposure period (REP, 1961-2001). Relative risks of lung cancer were calculated based on a meta-regression selected from the literature. PAFs were calculated using Levin's equation and applied to the 2011 lung cancer statistics obtained from the Canadian Cancer Registry. RESULTS: We estimated that 2.4% (95% CI 1.6% to 6.6%) of lung cancers in Canada are attributable to occupational DEE exposure, corresponding to approximately 560 (95% CI 380 to 1570) incident and 460 (95% CI 310 to 1270) fatal lung cancers in 2011. Overall, 1.6 million individuals alive in 2011 were occupationally exposed to DEE during the REP, 97% of whom were male. Occupations with the highest burden were underground miners, truck drivers and mechanics. Half of the attributable lung cancers occurred among workers with low exposure. CONCLUSIONS: This is the first study to quantify the burden of lung cancer attributable to occupational DEE exposure in Canada. Our results underscore a large potential for prevention, and a large public health impact from occupational exposure to low levels of DEE.

Exposure assessment in cohort studies of childhood asthma.

BACKGROUND: The environment is suspected to play an important role in the development of childhood asthma. Cohort studies are a powerful observational design for studying exposure-response relationships, but their power depends in part upon the accuracy of the exposure assessment. OBJECTIVE: The purpose of this paper is to summarize and discuss issues that make accurate exposure assessment a challenge and to suggest strategies for improving exposure assessment in longitudinal cohort studies of childhood asthma and allergies. DATA SYNTHESIS: Exposures of interest need to be prioritized, because a single study cannot measure all potentially relevant exposures. Hypotheses need to be based on proposed mechanisms, critical time windows for effects, prior knowledge of physical, physiologic, and immunologic development, as well as genetic pathways potentially influenced by the exposures. Modifiable exposures are most important from the public health perspective. Given the interest in evaluating gene-environment interactions, large cohort sizes are required, and planning for data pooling across independent studies is critical. Collection of additional samples, possibly through subject participation, will permit secondary analyses. Models combining air quality, environmental, and dose data provide exposure estimates across large cohorts but can still be improved. CONCLUSIONS: Exposure is best characterized through a combination of information sources. Improving exposure assessment is critical for reducing measurement error and increasing power, which increase confidence in characterization of children at risk, leading to improved health outcomes.