Maternal occupational exposure to organic solvents and intrauterine growth in the ELFE cohort

BACKGROUND

In developed countries, about 15% of women are occupationally exposed to solvents. Associations between this maternal occupational exposure and intrauterine fetal growth are inconsistent, but almost no existing study has investigated this relation by solvent family (oxygenated, petroleum, and chlorinated), although they may affect fetal growth differently.

OBJECTIVES

To investigate the relations between maternal occupational solvent exposure, by solvent family, and the risk of neonates born small for gestational age (SGA), or with low birthweight, or with small head circumference (HC).

METHODS

Among the 18,040 women enrolled in the Elfe rather than included in the Elfe birth cohort, we included 13,026 women who worked during pregnancy (72% of the cohort). Information about maternal occupations and industrial activities during pregnancy was collected by questionnaire at the maternity ward, and completed at 2-month when necessary. Using Matgéné job-exposure matrices, we assessed maternal occupational exposure to solvents. Logistic and multiple linear regressions were used to assess the association between maternal occupational solvent exposure and SGA status, birth weight, and HC. Analyses were conducted for exposure during pregnancy and also stratified by the trimester that pregnancy leave began.

RESULTS

We observed a higher risk of SGA newborns among mothers occupationally exposed during pregnancy to petroleum solvents (OR_adjusted = 1.26; 95%CI: 1.01 to 1.57). Among women working until the third trimester of pregnancy, we observed a higher risk of SGA newborns to those occupationally exposed to oxygenated solvents (OR_adjusted = 1.75; 95%CI: 1.11 to 2.75), a significantly lower birthweight for infants of mothers exposed to petroleum solvents (β_adjusted = -47.37 g; -89.33 to -5.42), and a lower HC among newborns of those occupationally exposed to oxygenated solvents (β_adjusted = -0.28; -0.49 to -0.07) and to chlorinated solvents (β_adjusted = -0.29; -0.53 to -0.05).

DISCUSSION

Our results suggest that maternal occupational solvent exposure may influence fetal growth, especially exposure into the third trimester of pregnancy.

Comparison of agreement in asthmagen exposure assessments between rule-based automatic algorithms and a job exposure matrix in healthcare workers in Australia and Bhutan

Background:

Assessment of occupational exposures is an integral component of population-based studies investigating the epidemiology of occupational diseases. However, all the available methods for exposure assessment have been developed, tested and used in high-income countries. Except for a few studies examining pesticide exposures, there is limited research on whether these methods are appropriate for assessing exposure in LMICs. The aim of this study is to compare a task-specific algorithm-based method (OccIDEAS) to a job-specific matrix method (OAsJEM) in the assessment of asthmagen exposures among healthcare workers in a high-income country and a low- and middle- income country (LMIC) to determine an appropriate assessment method for use in LMICs for future research.

Methods:

Data were obtained from a national cross-sectional survey of occupational asthmagens exposure in Australia and a cross-sectional survey of occupational chemical exposure among Bhutanese healthcare workers. Exposure was assessed using OccIDEAS and the OAsJEM. Prevalence of exposure to asthmagens and inter-rater agreement were calculated.

Results:

In Australia, the prevalence was higher for a majority of agents when assessed by OccIDEAS than by the OAsJEM (13 versus 3). OccIDEAS identified exposures to a greater number of agents (16 versus 7). The agreement as indicated by κ (Cohen’s Kappa coefficient) for six of the seven agents assessed was poor to fair (0.02 to 0.37). In Bhutan, the prevalence of exposure assessed by OccIDEAS was higher for four of the seven agents and κ was poor for all the four agents assessed (-0.06 to 0.13). The OAsJEM overestimated exposures to high-level disinfectants by assigning exposures to all participants from 10 (Bhutan) and 12 (Australia) ISCO-88 codes; whereas OccIDEAS assigned exposures to varying proportions of participants from these ISCO-codes.

Conclusion:

There was poor to fair agreement in the assessment of asthmagen exposure in healthcare workers between the two methods. The OAsJEM overestimated the prevalence of certain exposures. As compared to the OAsJEM, OccIDEAS appeared to be more appropriate for evaluating cross-country exposures to asthmagens in healthcare workers due to its inherent quality of assessing task-based determinants and its versatility in being adaptable for use in different countries with different exposure circumstances.

Testing and Validating Semi-automated Approaches to the Occupational Exposure Assessment of Polycyclic Aromatic Hydrocarbons

INTRODUCTION

When it is not possible to capture direct measures of occupational exposure or conduct biomonitoring, retrospective exposure assessment methods are often used. Among the common retrospective assessment methods, assigning exposure estimates by multiple expert rater review of detailed job descriptions is typically the most valid, but also the most time-consuming and expensive. Development of screening protocols to prioritize a subset of jobs for expert rater review can reduce the exposure assessment cost and time requirement, but there is often little data with which to evaluate different screening approaches. We used existing job-by-job exposure assessment data (assigned by consensus between multiple expert raters) from a large, population-based study of women to create and test screening algorithms for polycyclic aromatic hydrocarbons (PAHs) that would be suitable for use in other population-based studies.

METHODS

We evaluated three approaches to creating a screening algorithm: a machine-learning algorithm, a set of a priori decision rules created by experts based on features (such as keywords) found in the job description, and a hybrid algorithm incorporating both sets of criteria. All coded jobs held by mothers of infants participating in National Birth Defects Prevention Study (NBDPS) (n = 35,424) were used in developing or testing the screening algorithms. The job narrative fields considered for all approaches included job title, type of product made by the company, main activities or duties, and chemicals or substances handled. Each screening approach was evaluated against the consensus rating of two or more expert raters.

RESULTS

The machine-learning algorithm considered over 30,000 keywords and industry/occupation codes (separate and in combination). Overall, the hybrid method had a similar sensitivity (87.1%) as the expert decision rules (85.5%) but was higher than the machine-learning algorithm (67.7%). Specificity was best in the machine-learning algorithm (98.1%), compared to the expert decision rules (89.2%) and hybrid approach (89.1%). Using different probability cutoffs in the hybrid approach resulted in improvements in sensitivity (24-30%), without the loss of much specificity (7-18%).

CONCLUSION

Both expert decision rules and the machine-learning algorithm performed reasonably well in identifying the majority of jobs with potential exposure to PAHs. The hybrid screening approach demonstrated that by reviewing approximately 20% of the total jobs, it could identify 87% of all jobs exposed to PAHs; sensitivity could be further increased, albeit with a decrease in specificity, by adjusting the algorithm. The resulting screening algorithm could be applied to other population-based studies of women. The process of developing the algorithm also provides a useful illustration of the strengths and potential pitfalls of these approaches to developing exposure assessment algorithms.

Occupational Exposure to Carcinogens and Occupational Epidemiological Cancer Studies in Iran: A Review

INTRODUCTION

The extent of exposure to occupational carcinogens is not well characterized in Iran, and little is known about the burden of occupational cancer.

OBJECTIVES

This study aimed to describe exposure to occupational carcinogens and occupational epidemiology studies in Iran.

METHODS

Relevant studies up to January 2021 in Iran were identified through three databases (PubMed, Web of Science, and Google Scholar).

RESULTS

Forty-nine publications from 2009 to 2020 (one cohort, 11 case-control, 34 exposure monitoring studies, and three cancer burden studies) were included. The exposure monitoring studies were conducted mainly in the petroleum industry, metal industry, manufacturing of electronics, manufacturing of plastics, construction industry, and service industry. A few of the case-control studies also reported increased risk of cancers in relation to work in those industries.

CONCLUSIONS

Occupational cancer epidemiology in Iran is at an early stage. Both epidemiological and exposure monitoring studies are generally limited in size to provide robust evidence of occupational cancer risks. A coherent strategy to estimate the occupational cancer burden in Iran should start with conducting epidemiological studies along with systematic monitoring of occupational carcinogens for use in hazard control and research.

Are There Ethnic Disparities in Exposure to Workplace Hazards Among New Zealand Migrants to Australia?

Disparities in exposure to workplace hazards exist between Māori and non-Māori workers in New Zealand, with Māori workers generally incurring poorer conditions. This study aimed to determine if these ethnic disparities are similar after migration to Australia. A national cross-sectional telephone survey asked participants what tasks they undertook in their job to assess exposure to carcinogens as well as whether they experienced ethnic discrimination, bullying, job precariousness, or job strain. A total of 389 New Zealand Caucasians and 152 Māori/Pasifika workers were recruited. After adjustment, 79% of Māori/Pasifika compared with 67% of New Zealand Caucasian workers were assessed as being exposed to at least one carcinogen at work (adjusted prevalence ratio [aPR] = 1.2, 95% confidence interval [CI] = 1.1-1.4). Māori/Pasifika workers were also more likely to report ethnic discrimination (aPR = 6.9, 95% CI = 2.6-18.3) and fair or poor current health (aPR = 1.9, 95% CI = 1.1-3.2) than New Zealand Caucasians. Some ethnic disparities in exposure to workplace hazards in New Zealand are apparent after migration to Australia.

Occupational exposures to hazardous chemicals and agents among healthcare workers in Bhutan

BACKGROUND

Occupational exposures to hazardous chemicals among healthcare workers can result in long-term adverse health outcomes. Research on such exposures from low- and middle-income countries is limited. The aim of this study was to estimate the prevalence of exposures to a range of chemicals used in healthcare settings among Bhutanese healthcare workers.

METHODS

A cross-sectional study was conducted among healthcare workers (n = 370) working in three hospitals in the western region of Bhutan. Demographic and occupational information was collected, and exposures to asthmagens, carcinogens, ototoxic and other agents were assessed using a web-based tool. The prevalence of exposure to these chemicals was calculated and the circumstances resulting in such exposures were examined.

RESULTS

The prevalence of exposure to one or more asthmagen, carcinogen, and ototoxic agent was 98.7%, 28.1%, and 7.6%, respectively; and was 6.2% for anesthetic gases and 2.2% for antineoplastic drugs. The most common exposures were to latex, and cleaning and disinfecting agents in the asthmagens group; formaldehyde in the carcinogens group; and p-xylene among ototoxic agents. The circumstances resulting in exposures were using latex gloves, using bleach and chlorhexidine for cleaning, using formaldehyde as a disinfectant and in the laboratory, and using p-xylene in the laboratory.

CONCLUSIONS

The results indicate that a large proportion of Bhutanese healthcare workers are occupationally exposed to chemicals linked to chronic diseases, with exposure prevalence higher than in high-income countries. The study provides information that can be used to formulate policies and to implement control measures to protect healthcare workers.

Prevalence of exposure to multiple occupational carcinogens among exposed workers in Australia

OBJECTIVES

Workers can be exposed to a range of different carcinogenic agents in the workplace. However, previous studies have often focused on prevalence of exposure to a single carcinogen, resulting in substantial knowledge gaps regarding the extent of multiple exposures in the workplace. This study aims to investigate the current prevalence of occupational exposure to multiple carcinogens among exposed workers in Australia.

METHODS

The data for this study come from the Australian Work Exposures Study, a nationwide cross-sectional telephone survey of Australian workers aged between 18 and 65. Information was collected about the respondents' current employment and numerous demographic factors using a web-based application (Occupational Integrated Database Exposure Assessment System) to conduct the interview, with predefined algorithms used to automatically assign exposures to carcinogens based on the respondents' job tasks.

RESULTS

The majority (81%) of exposed respondents were assessed as being probably exposed to more than one carcinogen, and 26% reported exposure to five or more carcinogens. We found that after adjusting for occupation, exposure to multiple carcinogens was more likely among male respondents, while older workers (aged between 55 and 65) were less likely to be exposed to multiple carcinogens.

CONCLUSIONS

This study provides information on the prevalence of exposure to multiple carcinogens in the general population that has not previously been reported. This information could be useful for the intervention and control of occupational exposures to the prioritised carcinogens identified in this study.

Does exposure to workplace hazards cluster by occupational or sociodemographic characteristics? An analysis of foreign-born workers in Australia

BACKGROUND

Disparities in exposure to occupational hazards may be linked to social position as well as the type of job a person holds. This study aimed to describe the prevalence of exposure to workplace hazards among three migrant worker groups and to assess whether social disparities in exposure for these groups remain after adjusting for occupational characteristics.

METHODS

Data were collected in 2017/2018 from 1630 Australian workers born in New Zealand, India, and the Philippines. Weighted estimated prevalence of exposure to 10 carcinogens and four psychosocial hazards (discrimination, job strain, vulnerability, and insecurity) was calculated for sociodemographics and occupation. Regression estimated the likelihood of exposure by sociodemographics after adjustment for occupational characteristics.

RESULTS

Exposure to workplace hazards ranged from 11.7% (discrimination) to 61.2% (exposed to at least one carcinogen). Compared with workers born in India, New Zealand born workers were over twice as likely to be exposed to diesel engine exhaust (adjusted odds ratio [aOR] = 2.60) and 60% more likely to be exposed to at least one carcinogen (aOR = 1.60) but less likely to be exposed to any psychosocial hazard. Social disparities by country of birth, sex, age, education, and number of years in Australia, as well as company size, employment type, and hours, worked remained associated with greater likelihood of reporting one or more workplace hazards after adjusting for occupational characteristics.

CONCLUSION

Examining sociodemographic as well as occupational characteristics helps to clarify groups most likely to be exposed to workplace hazards who can be hidden when examining occupational characteristics alone.

Reliability and Validity of an Adapted Questionnaire Assessing Occupational Exposures to Hazardous Chemicals among Health Care Workers in Bhutan

BACKGROUND

Collection of reliable and valid occupational history data is of utmost importance to assess work-related exposures and their health effects. Few standardized questionnaires are available for the collection of occupational history data in low-and-middle income countries.

OBJECTIVE

To adapt and test a validated questionnaire developed in the United States by the National Institute of Safety and Health, in order to assess occupational chemical exposures among health care workers in Bhutan.

METHODS

The questionnaire was first adapted to suit the Bhutanese context with the advice of an expert review committee. 30 health care workers then completed the questionnaire at baseline and 10-14 days later. Test-retest reliability was assessed by calculating Cohen's κ and percentage agreement.

RESULTS

The questionnaire had high test-retest reliability. Cohen's κ ranged from 0.61 to 1.00, and percentage agreement ranged from 86.7% to 100%. Further adaptations included omitting questions on chemicals not available in Bhutan.

CONCLUSION

The adapted questionnaire is appropriate for assessing occupational chemical exposures among health care workers in Bhutan.

The estimated prevalence of exposure to carcinogens, asthmagens, and ototoxic agents among healthcare workers in Australia

BACKGROUND

Healthcare workers are occupationally exposed to various hazardous chemicals and agents that can potentially result in long-term adverse health effects. These exposures have not been comprehensively examined at a population level. The aim of this study was to examine occupational exposures to a wide range of asthmagens, carcinogens, and ototoxic agents among healthcare workers in Australia.

METHODS

Data were collected as part of the Australian Work Exposures Studies, which were computer-assisted telephone surveys conducted in 2011, 2014, and 2016 to assess the prevalence of occupational exposures to carcinogens, asthmagens, and ototoxic agents, respectively, among Australian workers. Using data on healthcare workers, the prevalence of exposures to these agents was calculated and associations of demographic variables and occupation groups with exposure status were examined.

RESULTS

The prevalence of exposure to at least one asthmagen, carcinogen, and ototoxic agent was 92.3%, 50.7%, and 44.6%, respectively. The most common exposures were to (a) cleaning and sterilizing agents in the asthmagen group; (b) shift work in the carcinogen group; and (c) toluene and p-xylene among ototoxic agents. Exposure varied by occupation, with exposure to carcinogens and ototoxic agents highest among personal carers and exposure to carcinogens most likely among nursing professionals and health and welfare support workers.

CONCLUSION

The results demonstrate that a substantial proportion of Australian healthcare workers are occupationally exposed to asthmagens, carcinogens, and ototoxic agents. These exposures are more common among certain occupational groups. The information provided by this study will be useful in prioritizing and implementing control strategies.

Case-Control Study of Paresthesia Among World Trade Center-Exposed Community Members

OBJECTIVE

To investigate whether paresthesia of the lower extremities following exposure to the World Trade Center (WTC) disaster was associated with signs of neuropathy, metabolic abnormalities, or neurotoxin exposures.

METHODS

Case-control study comparing WTC-exposed paresthesia cases with "clinic controls" (WTC-exposed subjects without paresthesias), and "community controls" (WTC-unexposed persons).

RESULTS

Neurological histories and examination findings were significantly worse in cases than controls. Intraepidermal nerve fiber densities were below normal in 47% of cases and sural to radial sensory nerve amplitude ratios were less than 0.4 in 29.4%. Neurologic abnormalities were uncommon among WTC-unexposed community controls. Metabolic conditions and neurotoxin exposures did not differ among groups.

CONCLUSIONS

Paresthesias among WTC-exposed individuals were associated with signs of neuropathy, small and large fiber disease. The data support WTC-related exposures as risk factors for neuropathy, and do not support non-WTC etiologies.