Association between organophosphate pesticide and cognitive behavior in children

• Main Authors: Yi-Ru Wang, 王羿茹
• Other Authors: Mei-Lien Chen
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/py5sy5

碩士 === 國立陽明大學 === 環境與職業衛生研究所 === 105 === Background Organophosphates pesticides (OPs) are widely used in Taiwan and these compounds are known for their neurotoxic properties. Recent studies indicate that pesticide exposures are commonly detected in some susceptible populations, including pregnant women and children. Children are highly susceptible to the neurotoxic effects of pesticides because their brain and central nervous system are developing rapidly. Objectives This study aimed to determine concentrations of urinary OPs metabolite in children from 2 to 13years of age and to examine the association between the concentrations of pre- and postnatal OP exposure and neurodevelopmental effects in children. Methods 1. We recruited 170 children aged 1 to 13 from two cohort. In CGH-Cohort, we recruited 46 pregnant women and 145 children. In CGH-Cohort, 20 pregnant mother and 25 children were recruited. Urine samples were collected from each participant and analyzed for metabolites of OPs by using GC/MS. Six analytes were measured including dimethylphosphate (DMP), dimethylthiophosphate (DMTP), dimethyldithiophosphate (DMDTP), diethylphosphate (DEP), diethylthiophosphate (DETP), and diethyldithiophosphate (DEDTP) . 2. In CGH-Cohort, we used the Wechsler Preschool and Primary Scale of Intelligence (WPPSI–R) to assess children's cognitive performance. In total, 40 children completed WPPSI–R scale. In addition, the parents completed the Swanson, Nolan, and Pelham, version IV scale (SNAP-IV) to measure the frequency of a variety of behaviors in 126 children. We performed analyses using SPSS statistics 20.0.The association between OPs exposure and WPPSI–R and SNAP-IV scale scores was assessed using multivariate linear regression models and logistic models. 3. In TMICS-Cohort, the Bayley Scales of Infant and Toddler Development (Bayley-III) was used to assess 25 children's development at 2 years old. We used Mann-Whitney U test to determine whether high OP exposure has different distribution in Bayley scales. Results After adjusting concentrations of urine, the geometric mean (GM) levels (nmol/g creatinine) of urinary DMP, DMTP, DMDTP, DEP, DETP, DEDTP, DMs, DEs, and DAPs were 20.32, 17.01, 11.35, 1.77,32.36 , 18.5, 75.42, 67.31, and 223.74, respectively. In this study, the urinary OPs levels in children were considerably higher than that in other countries. In CGH-Cohort and TIMCS-Cohort, we observed there was no statistically significant correlation between pre- and post-natal OP exposure and neurodevelopmental outcomes after adjusting for creatinine. However, we found that there was statistically significant correlation between postnatal DAP metabolites and inattention symptoms in children aged 7-13 in CGH-Cohort. Conclusion Due to the small sample size, the conclusion needs to be verified by increasing the sample size. After confirming the causal relationship, the implementation of further protection from the harmful effects of OP pesticides in children could be suggested.