Urinary Organophosphate Metabolites and Metabolic Biomarkers of Conventional and Organic Farmers in Thailand

Abstract

Organophosphate (OP) pesticides are used by most farmers to remove insects and to increase productivity; however, questions remain on the long-term health impacts of their use. This study assessed the relationship between OP biomarker levels and metabolic biomarker parameters. Conventional farmers (n = 213) and organic farmers (n = 225) were recruited, interviewed, and had physical health examinations. Serum glucose and lipid profiles, triglycerides, total cholesterol, high-density lipoproteins (HDL), and low-density lipoproteins (LDL) were measured. The average age, gender, education, and self-reported agricultural work time, work in second jobs, smoking status, alcohol consumption, insecticide use at home, home location near farmlands and years of pesticide use were significantly different between the conventional and organic farmers. The urinary OP metabolite levels were also significantly different between the two groups. With an increase in urinary diethyl phosphate, dimethyl phosphate and dialkyl phosphate metabolites, the total cholesterol, LDL and HDL, were significantly increased for all farmers after controlling for age, gender, alcohol consumption, years of pesticide use, and home location near farmlands. The results are consistent with our previous studies which suggests that pesticide usage, especially organophosphates, may increase the risk of cardiovascular disease and stroke among Thai farmers.

Residual Dialkyl Phosphate Metabolite Concentrations of Organophosphate Pesticides Among Indian Farmworkers

“…In addition, that DMP, DEP, and DETP metabolite levels detected in the present study were higher among the agricultural laborers as compared with other workers is consistent with earlier reported studies 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 …”

“…In the present investigation, farmworkers not using PPE showed that detectable levels of at least one DAP metabolite in urine are consistent with other studies conducted elsewhere 42,43 . Further, in the present investigation, DMP was the most frequently detected metabolite (100%) at the highest concentration level (74.91 μg · L −1 ; 17.616 μg · g −1 creatinine) followed by DETP (88%) and DEDTP (82%) among farmworkers when they have not used PPE, which are in line with previous studies' findings among farmworkers with minimal formal education and with low knowledge score on pesticide use 3–5,39,44–46 . Further, the duration of involvement in various agricultural activities and handling pesticides could be an important factor of exposure.…”

“…minimal formal education and with low knowledge score on pesticide use. [3][4][5]39,[44][45][46] Further, the duration of involvement in various agricultural activities and handling pesticides could be an important factor of exposure. Higher concentrations of DEP and DETP were detected among the studied farmworkers exposed to pesticides for more than 22 years.…”

“…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.…”

Acute health symptoms related to perception and practice of pesticides use among farmers from all regions of Thailand

“…The majority of studies in Thailand reported urinary dialkyl phosphate (DAP) metabolite levels which is a biomarker of organophosphate exposure. Recent studies in Thailand, farmers in all regions of Thailand had urine DAP levels that ranged from 87.32 to 122.2 microgram/gram creatinine (8)(9)(10). Additionally, the study by Suntudrob et al (11) monitored pesticide residues in vegetables from all provinces of Thailand, and reported that 22.3% of the samples had detectable pesticide residues with a range of <0.01-5.9 mg/kg.…”