Abstract
Concentrations of nine metabolites of organophosphate and pyrethroid insecticides, as well as two phenoxy herbicides, were determined in 322 urine samples collected from eight countries during 2006-2014 by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The target pesticides were found ubiquitously, indicating widespread exposure of humans to pesticides in these countries. The highest sum concentrations of 11 pesticides were found in urine collected from Vietnam (median, 28.9 ng/mL), followed in decreasing order by samples from India (14.2 ng/mL), China (13.6 ng/mL), Korea (12.5 ng/mL), Greece (12.3 ng/mL), Saudi Arabia (11.3 ng/mL), the USA (7.9 ng/mL), and Japan (7.1 ng/mL). Organophosphorus compounds accounted for 62-77% of the total urinary pesticide concentrations. Para-nitrophenol (metabolite of parathion and methyl parathion) and 3,5,6-trichloro-2-pyridinol (metabolite of chlorpyrifos and chlorpyrifos-methyl) were the major metabolites, especially in India (72%), China (69%), and Greece (66%). Differences in urinary pesticide concentrations between genders (male vs. female), age groups (categorized as ≤20, 21-49, and ≥50 years), and cities (Guangzhou, Shanghai, and Qiqihar) were examined. On the basis of the concentrations measured in urine, total daily intakes (DIs) of pesticides were estimated. The DIs of chlorpyrifos were found to be higher for populations in Vietnam, Greece, India, China, and Korea (≥9.6 μg/day) than those estimated for the other countries (<5 μg/day). The DIs of parathion (≥9.6 μg/day) in populations of China, India, and Korea were higher than those estimated for the other countries (5.7-9.3 μg/day). This is the first study to establish baseline levels of exposure of a variety of pesticides in several Asian countries.