Exposure to organophosphate insecticides, inappropriate personal protective equipment use, and cognitive performance among pesticide applicators

Abstract

Inappropriate use of personal protective equipment (PPE) among pesticide applicators may increase urinary organophosphate (OP) metabolite levels and subsequently increase risks of cognitive performance. Therefore, this study aims to (1) compare urinary OP metabolite levels and cognitive performance between pre-and post-pesticide application seasons; (2) PPE use and factors associated with PPE use linked to increased urinary OP metabolite levels during pesticide application; and (3) the association between urinary OP metabolite levels and cognitive performance. This longitudinal follow-up study on 79 pesticide applicators was carried out between October 2021 and January 2022. The applicators were interviewed, collected urine samples, and tested for cognitive performance in pre-and post-pesticide application seasons. The results found that the levels of urinary OP metabolites in post-application season were significantly higher than those in pre-application season (p < 0.001). Multiple linear regression analysis found that increased total diethylphosphate (DEP) and total dialkylphosphate (DAP) levels were associated with not wearing gloves while mixing pesticides [beta (β) ± standard error (SE) = −43.74 ± 18.52, 95% confidence interval (95% CI) = −80.84, −6.64 for total DEP and −50.84 ± 19.26, 95% CI = −89.41, −12.26 for total DAP] and also with not wearing a mask while spraying pesticides (β ± SE = −31.76 ± 12.24, 95% CI = −56.28, −7.24 for total DEP and −33.20 ± 12.63, 95% CI = −58.49, −7.92 for total DAP) after adjusting for covariates. The scores of Montreal Cognitive Assessment-Thai, Thai Mental State Examination, and Mini-Cognitive test in post-pesticide application were significantly lower than those in pre-pesticide application (p < 0.001). However, no association was found between urinary OP metabolite levels and cognitive decline. Our findings indicate that inappropriate PPE use during pesticide application was the major factor affecting urinary OP metabolite levels among pesticide applicators. Wearing gloves when mixing pesticides and a mask when spraying pesticides were key factors in reducing occupational exposure to OP. Exposure to OP at low levels and for short periods of exposure may not affect cognitive performance significantly. Therefore, long-term exposure and exposure to high levels of OP should be investigated further.

Residual Dialkyl Phosphate Metabolite Concentrations of Organophosphate Pesticides Among Indian Farmworkers

“…Studies conducted earlier were on the impact of the use of PPE on the DAP metabolites in the urine, but in the present study, an attempt was made to assess differences between commercially available PPE and the PPE prepared using the available resources, which could serve as a reference and may be one of its kind to the best of our knowledge as a part of the second phase of the intervention and could not be compared with any other studies because of lack of availability of the epidemiological data on the same. Overall, the present study findings demonstrate the minimization of OP exposure followed by reduction in DAP metabolite concentrations in urine samples among farmworkers when they have used PPE provided to them, which is in agreement with another study done elsewhere, indicating that the inadequacy or nonuse of PPE during pesticide application was the main factor impacting urine OP metabolite levels, and using adequate PPE such as gloves and a mask while handling pesticides is a significant variable in limiting occupational exposure to OPs 23 …”

“…Overall, the present study findings demonstrate the minimization of OP exposure followed by reduction in DAP metabolite concentrations in urine samples among farmworkers when they have used PPE provided to them, which is in agreement with another study done elsewhere, indicating that the inadequacy or nonuse of PPE during pesticide application was the main factor impacting urine OP metabolite levels, and using adequate PPE such as gloves and a mask while handling pesticides is a significant variable in limiting occupational exposure to OPs. 23 However, the results of the present study should be considered in light of its limitations. Although 24-hour voids provide more and complete information on the data collection, in the present study, the urine sample collection involved first-void samples, as the 24-hour void method is very onerous on participants, which may impact their level of participation, and hence, creatinine-corrected concentrations were used to reduce variability.…”

“…39 In the present study, higher mean concentrations of DMP, DEP, and DEDTP were observed among farmworkers storing the pesticides in their houses as compared with those storing in farm is in agreement with earlier reported studies, highlighting not only the effect of long-term exposure to pesticides and but also the nonadoption of GAPs by way of showing higher DAP metabolite levels. 23,46 The second-phase intervention study results showed reduced levels of DAP metabolites when farmworkers used commercially available and PPE prepared using the available resources provided to them. Studies conducted earlier were on the impact of the use of PPE on the DAP metabolites in the urine, but in the present study, an attempt was made to assess differences between commercially available PPE and the PPE prepared using the available resources, which could serve as a reference and may be one of its kind to the best of our knowledge as a part of the second phase of the intervention and could not be compared with any other studies because of lack of availability of the epidemiological data on the same.…”

“…21,22 A study has shown that urinary OP metabolite levels and subsequent risk of cognitive impairment may be increased when PPE is not used properly by pesticide applicators. 23 There is a lack of quantitative and qualitative data on relevant biomarkers of pesticide exposure, and concentrations of these chemicals in human biological samples make assigning cause-effect relationships to individual pesticides difficult. 24 Therefore, the present study aims to biomonitor the DAP metabolites in the urine samples of farmworkers of the Rangareddy district of Telangana, India, as a measure of chronic exposure to pesticides and also to assess the impact of PPE on their urinary levels.…”

Pesticide use behavior, cognitive impairment and the model of safety standard of pesticide use among farmworkers in Indonesia

“…PPE use during pesticide dissemination is recommended among farmworkers for protection as the chemical substances of pesticides can enter the human body through inhalation, as well as oral and skin routes. Chittrakul et al, 39 found that inappropriate use of PPE may elevate urinary organophosphate metabolite levels.…”