Systematic review of methods used to assess exposure to pesticides in occupational epidemiology studies, 1993–2017

Abstract

ObjectiveNumerous exposure assessment methods (EAM) exist for investigating health effects of occupational exposure to pesticides. Direct (eg, biomonitoring) and indirect methods (eg, self-reported exposures) are however associated with degrees of exposure misclassification. We systematically reviewed EAM in studies of occupational pesticide exposure.MethodsWe searched for articles reporting observational epidemiological studies in MEDLINE and Embase published 1993 to 2017. The relative frequency of EAM was analysed according to EAM type (direct and indirect methods), health outcome, study design, study location (country) and specificity of assessment. Temporal trends in EAM were analysed.ResultsIn 1298 included articles 1521 EAM occurrences were documented. Indirect EAM (78.3%), primarily self-reported exposures (39.3%) and job titles assessments (9.5%), were mainly applied in case-control studies (95.0%), in high-income countries (85.0%) and in studies of doctor-diagnosed health outcomes (>85%). Direct EAM (20.8%), primarily biomonitoring of blood (15.6%) or urine (4.7%), were predominantly applied in cross-sectional studies (29.8%), in lower middle-income countries (40.9%) and in studies of neurological (50.0%) outcomes. Between 1993 to 2017 no distinct time trends regarding the ratio indirect to direct methods was seen. Within the category of indirect methods use of self-reported exposures and job exposure matrices increased while assessments by job titles and registers decreased. The use of algorithms showed no trend. The specificity of pesticide assessment increased since studies assessing exposure by using job title as a proxy declined. Assessments of type of pesticide increased.ConclusionOver the last 25 years, the ratio (5:1) of indirect to direct EAM applied in articles on occupational pesticide epidemiology stayed relatively constant; changes were mainly attributable to increasing use of self-reported exposures and job exposure matrices. This review, combined with studies assessing EAM validity, will inform on magnitudes of exposure misclassification and help improve the quality of studies on occupational pesticides exposure.

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A tiered approach to prioritizing registered pesticides for potential cancer hazard evaluations: implications for decision making

“…As early as 1990, Blair and Zahm [ 35 ] noted that improvements in pesticide exposure assessments were necessary if epidemiologic investigations are to provide reliable information on the relationships between cancer incidence and pesticide exposure; however, change has been slow. Ohlander et al [ 36 ] reviewed over 1000 articles on occupational pesticide exposure and a range of health outcomes published between 1993 and 2017, and found that the majority of documented exposure assessment methods were indirect, usually based on self-reported exposure. They also found that the use of self-reported exposures and the specificity of pesticide assessments has increased somewhat over time, primarily due to the decreased used of job titles as proxies.…”

Non-Occupational Exposure to Pesticides: Experimental Approaches and Analytical Techniques (from 2019)

“…This exposure occurs mainly through inhalation of residues from aerial emissions produced during spray application, and through dermal exposure during any contact with pesticides (loading and cleaning equipment, deposition of particles during work, etc.) [ 25 , 27 ]. Hygiene and safety measures, as well as the use of personal protection equipment (PPE), are essential to reduce exposure in these circumstances [ 27 ].…”

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