Cumulative exposure assessment of neonicotinoids and an investigation into their intake-related factors in young children in Japan

Exposure levels of neonicotinoids (NEO) in young children remain unknown, despite their widespread use and the plausible vulnerability of toddlers to environmental toxicants. Hereinwe aimed to clarify the exposure levels and sources of NEOs in young Japanese children. Disposable diapers were collected from 1036 children (16-23 months old) participating in an adjunct study of the Japan Environment and Children's Study between 2015 and 2016. Six NEOs and one metabolite in urine extracted from a diaper from each child were analyzed using high-performance liquid chromatography-tandem mass spectrometry. A relative potency factor approach was used to assess the cumulative exposure to NEOs equivalent to dinotefuran levels (DINRPF). The 95th percentile urinary concentration of DINRPF was 157 mu g/L and 380 mu g/g creatinine (Cr). Receiver operating characteristic curve analyses for the propensity scores of the possible exposure-related factors revealed that the discriminatory powers determining whether Cr-adjusted and Cr-unadjusted DINRPF concentrations exceeding the 95th percentile values were higher for the amount of each foodstuff ingested on the survey day (areas under the curve were 0.62 and 0.75, respectively) than for the exposure-related behaviors (0.60 and 0.71, respectively) or formothers' attitudes toward food selection and preparation (0.54 and 0.57, respectively). Use of amosquito coil, insect repellent, and mothproof net for a screen door, and playing on a lawn were associated with increased urinary NEO levels (odds ratio [OR]: 2.0-2.9), while care about the child's nutritional balance bymothers reduced urinary NEO levels (OR: 0.23-0.41). To the best of our knowledge, this is the first study that dealtwith urinary concentrations and possible exposure sources of NEOs in a large number of young children. Attention to the children's behavior and diet might result in the reduction of a high exposure to NEOs in young children. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

This study investigated the exposure levels and sources of neonicotinoids (NEO) in young Japanese children, finding that food intake had a significant impact on exposure levels, while the use of mosquito coils and insect repellents was associated with increased urinary NEO levels. Mothers who were concerned about their child's nutritional balance were able to reduce the risk of exposure to NEOs.