Abstract
BackgroundPrevious studies stating a high prevalence of occupational acute pesticide poisoning in developing countries have mainly relied on measurements of the rather non-specific self-reported acute pesticide poisoning symptoms. Only a few studies have measured the biomarker plasma cholinesterase (PchE) activity, in addition to the symptoms, when assessing occupational acute pesticide poisoning. This study evaluated self-reported symptoms as a proxy for acute organophosphate poisoning among Nepali farmers by examining self-reported acute organophosphate poisoning symptoms and PchE activity in response to occupational acute organophosphate exposure.MethodsWe performed a randomized, double-blind, placebo-controlled, crossover trial among 42 Nepali commercial vegetable farmers. The farmers were randomly assigned (ratio 1:1) to a 2-h organophosphate (chlorpyrifos 50% plus cypermethrin 5%: moderately hazardous) spray session or a 2-h placebo spray session, and after 7 days’ washout, the farmers were assigned to the other spray session. Before and after each spray session farmers were interviewed about acute organophosphate poisoning symptoms and PchE activity was measured. Analyses were conducted with a Two Sample T-test and Mann Whitney U-test.ResultsWe found no difference in the symptom sum or PchE activity from baseline to follow up among farmers spraying with organophosphate (symptom sum difference −1, p = 0.737; PchE mean difference 0.02 U/mL, p = 0.220), placebo (symptom sum difference 9, p = 0.394; PchE mean difference 0.02 U/mL, p = 0.133), or when comparing organophosphate to placebo (symptom p = 0.378; PchE p = 0.775). However, a high percentage of the farmers reported having one or more symptoms both at baseline and at follow up in the organophosphate spray session (baseline 47.6%, follow up 45.2%) and placebo spray session (baseline 35.7%, follow up 50.0%), and 14.3% of the farmers reported three or more symptoms after the organophosphate spray session as well as after the placebo spray session.ConclusionWe found a general presence of acute organophosphate symptoms among the farmers regardless of organophosphate exposure or poisoning. Thus, self-reported acute organophosphate symptoms seem to be a poor proxy for acute organophosphate poisoning as the occurrence of these symptoms is not necessarily associated with acute organophosphate poisoning.Trial registrationClinicalTrials.gov, NCT02838303. Registered 19 July 2016. Retrospectively registered.Electronic supplementary materialThe online version of this article (doi:10.1186/s12940-016-0205-1) contains supplementary material, which is available to authorized users.
Highlights
Previous studies stating a high prevalence of occupational acute pesticide poisoning in developing countries have mainly relied on measurements of the rather non-specific self-reported acute pesticide poisoning symptoms
We found a general presence of acute organophosphate symptoms among the farmers regardless of organophosphate exposure or poisoning
Study design We performed a randomized, double-blind, placebocontrolled, crossover trial collecting baseline and follow up measures of self-reported acute organophosphate poisoning symptoms and plasma cholinesterase (PchE) activity in Nepali farmers randomized to either Group A or Group B
Summary
Previous studies stating a high prevalence of occupational acute pesticide poisoning in developing countries have mainly relied on measurements of the rather non-specific self-reported acute pesticide poisoning symptoms. A few studies have measured the biomarker plasma cholinesterase (PchE) activity, in addition to the symptoms, when assessing occupational acute pesticide poisoning. This study evaluated self-reported symptoms as a proxy for acute organophosphate poisoning among Nepali farmers by examining self-reported acute organophosphate poisoning symptoms and PchE activity in response to occupational acute organophosphate exposure. Previous studies stating a high prevalence of occupational acute pesticide poisoning among farmers in developing countries [7,8,9,10,11,12,13] have mainly relied on measuring self-reported acute pesticide poisoning symptoms when assessing the prevalence. Plasma cholinesterase (PchE) activity is considered a valid biomarker of acute pesticide exposure and poisoning [5, 6, 14], to date only a few studies have measured PchE activity in relation to occupational pesticide poisoning [15,16,17,18,19] and these studies have mainly examined occupational chronic pesticide poisoning
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.