A Longitudinal Approach of Assessing Urban and Suburban Children’s Exposure to Pyrethroid Pesticides

Abstract

P-448 Introduction: Although pyrethroids have been sold in the U.S. consumer market for more than 30 years with the estimated annual use ranging from several thousands to a million pounds, very few studies have been conducted to quantitatively assess human exposures to pyrethroids. Most of the relevant data were obtained from studies conducted in Germany or in occupational setting. Recently, the Center for Disease Control and Prevention reported urinary pyrethroid metabolites levels for the U.S. population aged 6–59 years in the National Health and Nutrition Examination Survey (NHANES) conducted in 2001–2002. All of these studies were conducted cross-sectionally, and therefore, the results only represent exposures over relatively short time periods. The primary objective of this study was to establish a temporal profile of pyrethroid exposure in a cohort of elementary school-aged children living in an urban/suburban community using urinary pyrethroid metabolites as exposure biomarkers. We also examined the relationship between pyrethroid exposure and children’s diets, self-reported residential pyrethroid use, and age. Methods: We conducted a longitudinal study to assess 23 elementary school-aged children’s exposure to pyrethroid pesticides using urinary pyrethroid metabolites as exposure biomarkers. We substituted most of children’s conventional diets with organic food items for 5 consecutive days, and collected two daily spot urine samples, first morning and before the bedtime voids, throughout the 15-day study period. Urine samples were analyzed for 5 common pyrethroid metabolites. Results: We found the association between self-reported pyrethroids use in the residential environment by the parents and the elevated pyrethroid metabolite levels found in their children’s urine. Children also expose to pyrethroids through their conventional diets, although the magnitude is smaller than the residential exposure. Children’s ages appear to be significantly associated with pyrethroids exposure, which is likely attributed by the use of pyrethroids around the premise or in the facilities where older age children engaged in the outdoor activities. Conclusion: We conclude that residential pesticide use represents the most important risk factor for children’s exposure to pyrethroid insecticides. Because of the wide use of pyrethroids in the U.S., the findings of this study are important from both the children’s pesticide exposure assessment and the environmental public health perspectives.