A Longitudinal Approach of Assessing Aggregate Exposure to Organophosphorus Pesticides in ChildrenEPA Grant Number: R829364
Title: A Longitudinal Approach of Assessing Aggregate Exposure to Organophosphorus Pesticides in Children
Investigators: Lu, Chensheng (Alex) , Fenske, Richard
Institution: University of Washington - Seattle
EPA Project Officer: Hahn, Intaek
Project Period: September 1, 2001 through August 31, 2005
Project Amount: $1,246,407
RFA: Aggregate Exposure Assessment for Pesticides: Longitudinal Case Studies (2001) RFA Text | Recipients Lists
Research Category: Pesticides , Health , Safer Chemicals , Health Effects
This study has three primary objectives. First, it is designed to characterize the temporal and inter-individual variability of total organophosphorus (OP) pesticide exposures in children in relation to both residential pesticide use and dietary intake. Second, this study will examine children's OP pesticide exposure from multiple sources via several unique pathways, and will assess the relative contribution of these pathways and sources to total OP pesticide body burden. Third, this study will establish a baseline level of OP pesticide exposures in children, and will determine the contribution of OP pesticide residues in children's diets to this baseline.
We propose a combination of biological monitoring and multi-pathway sampling techniques as complementary approaches to exposure characterization in which not only children's exposure to OP pesticides can be more effectively and accurately assessed, but is likely to generate meaningful results as well. The study design for this project has three components. First, we will conduct a longitudinal biomonitoring study in which spot urine samples will be collected from a cohort of children ages 2-12 residing in the Seattle metropolitan area for a 12-month period. The second component of this study focuses on assessing aggregate OP pesticide exposures to children with elevated OP pesticide exposures, as measured in the previous longitudinal biomonitoring study. We will sample environmental and biological media, including soil, indoor air, dust, duplicate diet and urine, before and after a known exposure event occurred. The third component of this study is to establish a baseline level of OP pesticide exposure in this cohort. We will estimate the contribution of dietary OP pesticide ingestion to this baseline level by providing exclusive organic produce to children for a week during the low OP exposure period. We anticipate a drop of the baseline, follow by a gradual return to the normal levels when conventional produce is reintroduced.
The work outlined in this proposal is likely to expand knowledge regarding children?s aggregate exposures to pesticides. First, this work will establish a temporal profile of OP pesticide exposures to young children and will evaluate the relationship between this profile and both residential pesticide use and children's diets. This valuable database will have the implication of implementing the requirements under FQPA 1996. Second, we intend to demonstrate that the outcome from the longitudinal study will assist us in designing a cost-effective multi-pathway sampling study in which key exposure pathways are evaluated at the time of occurrence. It is also likely that this study will result in the establishment of a baseline level of OP pesticide exposure in children residing in metropolitan communities. This information will have the implications for cumulative risk assessment, and for regulations regarding a health-based pesticide exposure standard for children.