Trends in inhalation exposure to hydrocarbons among commercial painters in The Netherlands

Maternal occupational exposure to endocrine-disrupting chemicals and urogenital anomalies in the offspring

STUDY QUESTION

Is there an association between maternal occupational exposure to endocrine-disrupting chemicals (EDCs) early in pregnancy and subgroups of congenital anomalies of kidney and urinary tract (CAKUT), and hypospadias?

SUMMARY ANSWER

Exposure to specific EDCs can increase the risk of CAKUT and no association with hypospadias was observed.

WHAT IS KNOWN ALREADY

Previous studies showed an association between maternal occupational exposure to EDCs and hypospadias. However, little is known about the effect of these chemicals on the development of CAKUT, especially subgroups of urinary tract anomalies.

STUDY DESIGN, SIZE, DURATION

For this case-control study, cases with urogenital anomalies from the European Concerted Action on Congenital Anomalies and Twins Northern Netherlands (Eurocat NNL) registry and non-malformed controls from the Lifelines children cohort (living in the same catchment region as Eurocat NNL) born between 1997 and 2013 were selected. This study included 530 cases with CAKUT, 364 cases with hypospadias, 7 cases with both a urinary tract anomaly and hypospadias and 5602 non-malformed controls. Cases with a genetic or chromosomal anomaly were excluded, and to avoid genetic correlation, we also excluded cases in which a sibling with the same defect was included.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Information on maternal occupation held early in pregnancy was collected via self-administered questionnaires. Job titles were translated into occupational exposure to EDCs using a job-exposure matrix (JEM). Adjusted odds ratios (aORs) and 95% CIs were estimated to assess the association between maternal occupational exposure to EDCs (and to specific types of EDCs) and CAKUT and hypospadias.

MAIN RESULTS AND THE ROLE OF CHANCE

For CAKUT and hypospadias, 23.1% and 22.9% of the cases were exposed to EDCs, respectively, whereas 19.8% of the controls were exposed. We found an association between maternal occupational exposure to organic solvents/alkylphenolic compounds and CAKUT (aOR 1.41, 95% CI 1.01-1.97) that became stronger when combinations of urinary tract anomalies co-occurred with other defects (aOR 7.51, 95% CI 2.41-23.43). An association was also observed for exposure to phthalates/benzophenones/parabens/siloxanes and CAKUT (aOR 1.56, 95% CI 1.06-2.29), specifically urinary collecting system anomalies (aOR 1.62, 95% CI 1.03-2.54) and combinations of urinary tract anomalies (aOR 2.90, 95% CI 1.09-7.71). We observed no association between EDC exposure and hypospadias.

LIMITATIONS, REASONS FOR CAUTION

The different study designs of Eurocat NNL and Lifelines could have introduced differential information bias. Also, exposure misclassification could be an issue: it is possible that the actual exposure differed from the exposure estimated by the JEM. In addition, women could also have been exposed to other exposures not included in the analysis, which could have resulted in residual confounding by co-exposures.

WIDER IMPLICATIONS OF THE FINDINGS

Women, their healthcare providers, and their employers need to be aware that occupational exposure to specific EDCs early in pregnancy may be associated with CAKUT in their offspring. An occupational hygienist should be consulted in order to take exposure to those specific EDCs into consideration when risk assessments are carried out at the workplace.

STUDY FUNDING/COMPETING INTEREST(S)

N.S. was paid by the Graduate School of Medical Sciences (MD/PhD programme), University Medical Center Groningen (UMCG), Groningen, the Netherlands. Eurocat Northern Netherlands is funded by the Dutch Ministry of Health, Welfare and Sports. The Lifelines Biobank initiative has been made possible by subsidy from the Dutch Ministry of Health, Welfare and Sport, the Dutch Ministry of Economic Affairs, the University Medical Center Groningen (UMCG the Netherlands), University Groningen and the Northern Provinces of the Netherlands. The authors report no conflict of interest.

TRIAL REGISTRATION NO

N/A.

Lung cancer risk in painters: results from the SYNERGY pooled case-control study consortium

OBJECTIVES

We evaluated the risk of lung cancer associated with ever working as a painter, duration of employment and type of painter by histological subtype as well as joint effects with smoking, within the SYNERGY project.

METHODS

Data were pooled from 16 participating case-control studies conducted internationally. Detailed individual occupational and smoking histories were available for 19 369 lung cancer cases (684 ever employed as painters) and 23 674 age-matched and sex-matched controls (532 painters). Multivariable unconditional logistic regression models were adjusted for age, sex, centre, cigarette pack-years, time-since-smoking cessation and lifetime work in other jobs that entailed exposure to lung carcinogens.

RESULTS

Ever having worked as a painter was associated with an increased risk of lung cancer in men (OR 1.30; 95% CI 1.13 to 1.50). The association was strongest for construction and repair painters and the risk was elevated for all histological subtypes, although more evident for small cell and squamous cell lung cancer than for adenocarcinoma and large cell carcinoma. There was evidence of interaction on the additive scale between smoking and employment as a painter (relative excess risk due to interaction >0).

CONCLUSIONS

Our results by type/industry of painter may aid future identification of causative agents or exposure scenarios to develop evidence-based practices for reducing harmful exposures in painters.

Cross-classified occupational exposure data

We demonstrate the regression analysis of exposure determinants using cross-classified random effects in the context of lead exposures resulting from blasting surfaces in advance of painting. We had three specific objectives for analysis of the lead data, and observed: (1) high within-worker variability in personal lead exposures, explaining 79% of variability; (2) that the lead concentration outside of half-mask respirators was 2.4-fold higher than inside supplied-air blasting helmets, suggesting that the exposure reduction by blasting helmets may be lower than expected by the Assigned Protection Factor; and (3) that lead concentrations at fixed area locations in containment were not associated with personal lead exposures. In addition, we found that, on average, lead exposures among workers performing blasting and other activities was 40% lower than among workers performing only blasting. In the process of obtaining these analyses objectives, we determined that the data were non-hierarchical: repeated exposure measurements were collected for a worker while the worker was a member of several groups, or cross-classified among groups. Since the worker is a member of multiple groups, the exposure data do not adhere to the traditionally assumed hierarchical structure. Forcing a hierarchical structure on these data led to similar within-group and between-group variability, but decreased precision in the estimate of effect of work activity on lead exposure. We hope hygienists and exposure assessors will consider non-hierarchical models in the design and analysis of exposure assessments.

A screening programme on chronic solvent-induced encephalopathy among Dutch painters

BACKGROUND

Long-term exposure to organic solvents may lead to chronic solvent induced encephalopathy (CSE) in painters. In combination with reduction of exposure, a workers' health surveillance programme was developed, resulting in a three-stage CSE screening procedure for early neurobehavioural changes possibly predicting chronic health effects. The screening consists of a questionnaire (Neurosymptom Screening Checklist 60, NSC-60), computerised neurobehavioural functioning testing (Neurobehavioural Evaluation System; NES2) and multidisciplinary differential diagnostic evaluation by experts (called 'Solvent Team'). Results from the screening were compared with the results of the 'care as usual' (CAU), in which symptomatic patients were referred directly to the Solvent Team by occupational physicians, general practitioners or medical specialists. Parallel to the screening programme, a legal ban on indoor use of solvent-based paints resulted in lower exposure to solvents.

OBJECTIVE

To investigate the usefulness of the NSC-60 questionnaire as a screening tool for CSE among painters and to investigate the course of the number of CSE cases over the years as a potential consequence of improved prevention and control.

RESULTS

From 1998 to 2004, more than 40,000 painters were invited to participate in a health surveillance programme including a periodical occupational health examination (PHE) and 50% did participate. Four percent (N=794) of these had a positive score on the NSC-60. The Solvent Team assessed 101 of these for CSE, which resulted in 27 CSE cases diagnosed. CAU during the same period of the surveillance (1998-2004) yielded 619 painters and 75 of these had the diagnosis CSE. After 2002 the number of CSE diagnosed cases dropped considerably and in 2004 only one case of CSE could be diagnosed. The substantially lower prevalence of CSE diagnosed cases in painters after 2002 might partly be explained as a result of a successful participation in the screening procedure of most prevalent CSE cases during the years 1998-2002. A second reason for the reduction of new diagnosed cases of CSE can be the effectiveness of the ban on indoor use of solvent-based paints resulting in lower exposure levels at work.

CONCLUSION

The screening procedure is useful to screen for CSE among people taking part in the PHE programme. Control of CSE can be achieved by an integrated preventive approach with reduction of exposure and screening on early health effects.

Chronic solvent-induced encephalopathy: European consensus of neuropsychological characteristics, assessment, and guidelines for diagnostics

INTRODUCTION

The presence of neuropsychological impairment is a hallmark of chronic solvent-induced encephalopathy (CSE), and using clinical neuropsychological procedures to generate a valid assessment of the condition is crucial for its diagnosis. The goals of this consensus document are to provide updated knowledge of the neuropsychological characteristics of CSE and to provide internationally acceptable guidelines for using neuropsychological assessments in the process of diagnosing patients who are suspected of having CSE.

MATERIALS AND METHODS

A European working group that was composed of experts in the field of the clinical diagnosis of CSE met at several round-table meetings and prepared this report. The first section of the consensus paper addresses a review of the relevant literature that was published between 1985 and March 2012. The second section addresses recommendations for the clinical neuropsychological assessment of patients who are suspected of having CSE.

RESULTS

The literature review indicates that the most common neuropsychological impairments in CSE patients are within the domains of attention, particularly the speed of information processing, memory, and motor performance. It appears that the influence of CSE on memory processes mainly involves immediate recall and generally involves verbal, visual and visuospatial material. In the second section, six recommendations are presented regarding important functional domains for the neuropsychological diagnostic process of CSE that relate to the evaluation of neuropsychological impairment, the assessment and evaluation of symptoms, differential diagnostic considerations, the reliability and validity of neuropsychological test results, and the retesting of patients.

DISCUSSION AND CONCLUSIONS

These recommendations will contribute to the improvement of the process for accurately diagnosing CSE, better counselling for CSE patients, the comparability of epidemiological data between countries, and finally, by raising awareness, these recommendations will contribute to combating the adverse health effects of occupational exposure to solvents.

Development of solvent exposure index for construction painters

This article describes methodological approaches for reconstructing long-term occupational exposure to organic solvents among construction painters. A detailed exposure questionnaire was administered to 125 painters to develop a job exposure matrix (JEM). The questionnaire inquired about painting activities with solvent-based paints and use of protection equipment for the previous 25 years in 5-year intervals. Current and historical distributions of solvent air concentrations were assessed for the same time period based on the following information: industrial hygiene measurements, paint composition changes, and VOC emission rate changes from architectural and industrial maintenance coatings. Changes in protection factors of respirators were also assessed. A cumulative solvent exposure index was calculated for each painter through Monte Carlo simulations by combining appropriate input distributions of solvent air concentrations and protection factors of respirators with JEM. Sensitivity simulations revealed that the historical variations in solvent air concentrations had a higher impact on the cumulative solvent exposure index than changes in protection factors for respirators. Fifty-eight percent of painters were classified with a different exposure quartile when the solvent exposure index was used vs. an exposure based only on years using solvent-based paints, suggesting the need for more detailed exposure analysis than just years working when conducting epidemiologic studies for this worker population.

Measurement error and model specification in determining how duration of tasks affects level of occupational exposure

Statistical modeling of determinants of exposure ascertained in large-scale surveys is an increasingly popular approach to both (i) identifying effective occupational exposure controls that arise in 'natural experiments' and (ii) predicting how altering some working conditions may impact exposure levels. This paper sheds light on two underappreciated methodological challenges of such studies. First, I examine the impact of measurement error in the observed determinant of exposure on an investigator's ability to correctly rank the determinants of exposure in terms of their exposure rate (one aspect of how important a give determinant is). Simultaneously, I consider the issue of whether empirical models fitted for the sake of statistical convenience actually reflect the physical reality that is being modeled and how this may affect the answer to the question about ranking determinants of exposure. These general issues are examined in the context of the 'time per task' determinant of exposure and true exposure model that states that exposure is equal to product of exposure rate and duration of a task. Simulation studies were conducted and their conclusions applied in re-examining the data on the impact of duration of some key task on exposure levels to flour dust among bakers. The simulation study demonstrated that bias due to measurement error in observed effects can be either positive or negative. The main conclusion is that the correct ranking of exposure rates can be obtained from both true and poorly specified exposure models, but can be severely distorted by errors in estimates of the duration of tasks performed.

Adverse reproductive outcomes among male painters with occupational exposure to organic solvents

OBJECTIVES

To assess the risks of reproductive disorders and birth defects in offspring of male painters with exposure to organic solvents, and to determine the shape of the dose-response relationship.

METHODS

Random samples of painters and carpenters were drawn from workers affiliated with the Dutch Trade Union for Construction Workers, the Netherlands, 2001. Information on reproductive outcomes, occupational exposures, and lifestyle habits was retrospectively obtained through self-administered questionnaires filled in by 398 painters exposed to organic solvents in paints, thinners, and cleansers in the period of three months before the last pregnancy, and 302 carpenters with little or no exposure to solvents. A statistical model was used to estimate quantitative exposure measures.

RESULTS

Workers employed as painters at three months before pregnancy had an increased risk (odds ratio 6.2, 95% CI 1.4 to 27.9) of congenital malformations in offspring compared to carpenters. There was a positive exposure-response trend with increasing exposure to organic solvents based on quantitative model predicted exposure estimates using toluene as a marker. There was some indication of an increased risk of functional developmental disorders in offspring among painters with intermediate and high model predicted exposure. The risk of low birth weight children seemed to be slightly increased among painters as well. Results for other reproductive outcomes (time to pregnancy, spontaneous abortion, and preterm birth) did not show increased risks.

CONCLUSION

This study showed a positive association between paternal occupational exposure to organic solvents and congenital malformations in offspring. However, the small numbers of cases, especially when examining different exposure levels, as well as the self-reported nature of exposure and outcome variables, may hamper interpretation of the results.

A probabilistic assessment of the impact of interventions on oncology nurses' exposure to antineoplastic agents

OBJECTIVE

The main goal was to investigate the potential of a probabilistic approach for exposure assessment and use this information to evaluate the impact of a complex of policy actions/interventions on dermal exposure to antineoplastic agents among oncology nurses. The central theme of this study was to make optimal use of existing data, supplemented only with limited additional information from a questionnaire survey.

METHODS

A task based exposure model was used to estimate dermal exposure of the hands among oncology nurses in non-academic hospitals in the Netherlands. Monte Carlo simulation was used to integrate information from available (exposure) studies and generate exposure distributions for the total population of oncology nurses in both pre- and post-intervention situation. Graphs and descriptive statistics of the simulated exposure distributions were used to evaluate trends in population exposure.

RESULTS

The inventory showed that important intervention occurred in the preparation and administering of antineoplastic agents and in the handling of urine. Hardly any changes were identified in de nursing tasks. The use of gloves seemed to have decreased for a number of tasks. The results of the analysis show that the interventions did not affect the median exposure. However frequencies of occurrence of individuals with very high and very low total dermal exposures decreased substantially in the post-intervention situation. Analysis of the effect of pregnancy showed that pregnancy is very unlikely to influence exposure or any of the key input variables.

CONCLUSIONS

The present study shows that the probabilistic approach adds valuable information to deterministic exposure assessment, especially when extrapolating data on a subpopulation to populations of individuals at large. The results show that the identified changes in the past decade in Dutch non-academic hospitals resulted in changes in the exposure distribution of antineoplastic agents among oncology nurses.