Exposure characterization of three major insecticide lines in urine of young children in Japan-neonicotinoids, organophosphates, and pyrethroids

The use of neonicotinoid (NEO) insecticides has increased over the past decade not only in Japan but also worldwide, while organophosphate (OP) and pyrethroid (PYR) insecticides are still conventionally used in agriculture and domestic pest control. However, limited data are currently available on the NEO exposure levels, especially in children, who are particularly vulnerable to environmental toxicants. Thus, the purpose of this study was to characterize the exposure to NEOs, as well as OPs and PYRs, in three-year-old Japanese children by assessing the range, distribution, and seasonal differences of the urinary concentrations of seven NEOs (acetamiprid, clothianidin, dinotefuran, thiacloprid, thiamethoxam, imidacloprid, and nitenpyram); four OP metabolites (dialkylphosphates IDAPsp, including dimethylphosphate, dimethylthiophosphate, diethylphosphate, and diethylthiophosphate; and three PYR metabolites (3-phenoxybenzoic acid, trans-chrysanthemumdicarboxylic acid, and 3-(2,2-dichloroviny1)-2,2- dimethylcyclopropane carboxylic acid). Urine samples were collected from 223 children (108 males and 115 females) in the summer and winter months. The detection rates of NEOs were 58% for dinotefuran, 25% for thiamethoxam, 21% for nitenpyram, and <16% for all other NE05. The median and maximum concentrations of the sum of the seven NEOs (NEO) were 4.7 and 370.2 nmol/g creatinine, respectively. Urinary Sigma NEO, dimethylphosphate, and all PYR metabolite concentrations were significantly higher in the summer than in the winter (p < 0.05). The creatinine-adjusted concentration of Sigma NEO significantly correlated with those of all DAPs (p < 0.05) but not with those of the PYR metabolites. Moreover, the NEO-detected group showed higher urinary EDAP (sum of four OP metabolites) concentrations than the group without NEO detection. These findings suggest that children in Japan are environmentally exposed to the three major insecticide lines, and that the daily exposure sources of NEOs are common to those of Ups. (C) 2016 Elsevier Inc. All rights reserved.