Abstract:
The prevalence of attention deficit/hyperactivity disorder (ADHD) is rising in Thai children. The possible causes of this developmental disorder include environmental and genetic risk factors. Organophosphate (OP) and pyrethroid (PYR) are insecticides popularly used in agricultural areas. The epidemiological evidence on their potential neurobehavioral effects in children is lacking. This study aimed to clarify the relationship of levels of OP and PYR exposure and ADHD behaviors compared between children living in rice farming area and children living in aquacultural farming area. The cross-sectional study was done in 3 sessions: pilot, high (wet season) and low (dry season) pesticide use periods. Participants (N=53) aged between 6-8 years old were recruited. The first morning void of urine samples and blood cholinesterase were collected. Participants assessed the continuous performance test (CPT) form the Behavioral Assessment and Research System (BARS) and their parents completed the Conners ADHD questionnaires. Although the concentrations of urinary OP metabolites in participants living in rice area were significantly higher than participants living in aquacultural areas (Mann-Whiney U test, p <0.05). most of neurobehavioral health effect were not differents between groups in every seasons. from the multiple linear regression (adjusted for age, parent education, and family income), both concentrations of urinary OP metabolite (dialkyphosphate,DAP ). urinary PYR metabolite (3-phenoxybenzyl alcohol; 3-PBA ), and blood cholinesterase levels (acetycholinesterase; Ache and pseudocholonesterase; PChE) were not significantly associated with CPT scores and ADHD symptoms. However, this study showed the validity of the behavioral tests by the significant correlation between CPT and Conners questionnaires(r=0.29, p=0.03) as a reflection of AHAD behaviors. As a pilot study of research project on behavioral health effects of children living in agricultural area in Thailand, the longitudinal study with larger study population should be conducted on potential neurobehavioral effects of long-term exposure of OP and PYR in children.
