Measurements and Models of Longitudinal Dietary Intake of Pyrethroid and Organophosphate Insecticides by Children

EPA Grant Number: R829396
Title: Measurements and Models of Longitudinal Dietary Intake of Pyrethroid and Organophosphate Insecticides by Children
Investigators: Ryan, P. Barry , Hassan, Sayed , Kerr, William L.
Institution: Emory University , University of Georgia
EPA Project Officer: Hahn, Intaek
Project Period: February 1, 2002 through March 31, 2010
Project Amount: $659,764
RFA: Children's Vulnerability to Toxic Substances in the Environment (2001) RFA Text |  Recipients Lists
Research Category: Health Effects , Children's Health , Health


The goal of the proposed research is to measure longitudinal dietary exposure of selected insecticides for children, to evaluate the accuracy of children's dietary exposure models, and to reduce the model uncertainty. The target insecticides are the pyrethroid compounds: cypermethrin, esfenvalerate, fenpropathrin, and permethrin; and the organophosphate compounds: acephate, azinphos-methyl, diazinon, malathion, and phosmet. Hypotheses will be tested regarding (1) the equivalence of single measure and repeated measure (i.e., long-term average) dietary exposures, and (2) the equivalence of measured dietary exposure and modeled dietary exposure; for both a population of children and for individual children over acute, short-term, intermediate-term, and chronic exposure periods.


Duplicate diet samples and food consumption diaries will be obtained for at least 80 children aged one to five years old in each of 8 monitoring cycles spaced over a one-year period from March 2002 through February 2003. The duplicate diet samples will be analyzed for the target insecticides to provide a direct measure of personal dietary exposure to those compounds. Statistical techniques, including mixed generalized linear models will be used to test for significant temporal variability of measured dietary exposure and food consumption patterns over acute, short-term, and intermediate exposure periods. The intraclass correlation coefficient of reliability will be used to quantify between-child and within-child variation of dietary exposure based upon the repeated measure data. Food items recorded on the diaries will be matched to USDA food codes and translated to food commodities using an USDA/EPA database. The commodity consumption data will be combined with commodity-specific pesticide residue data from USDA, EPA, and FDA databases to model dietary exposure for each participant and exposure duration. Correlation and regression analysis will be used to describe associations between measured and modeled dietary intake of pesticides. Results of these analyses will allow us to evaluate the accuracy of the food consumption-chemical composition model for the population of children and for individual children.

Expected Results:

Successful completion of the proposed research will contribute to improved understanding of exposure to pyrethroid and organophosphate insecticides during crucial periods of development. The proposed design will afford exploration of intermittent and time-varied exposures during early childhood. A data set of longitudinal food consumption patterns for children will be collected that can be used in dietary exposure and risk assessments for any food borne compound. The data, methods, and knowledge obtained from this research will be valuable for evaluating children's personal exposure to insecticides and possible health risks through epidemiological studies, clinical studies, and quantitative risk assessment.

Publications and Presentations:

Publications have been submitted on this project: View all 14 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 4 journal articles for this project

Supplemental Keywords:

sensitive populations, neurotoxins, agriculture, community based., RFA, Health, Scientific Discipline, PHYSICAL ASPECTS, Air, Toxics, air toxics, Health Risk Assessment, pesticides, Risk Assessments, Susceptibility/Sensitive Population/Genetic Susceptibility, Biochemistry, Physical Processes, Children's Health, genetic susceptability, monitoring, pesticide exposure, rural communities, sensitive populations, urban air, adolescents, organophosphates, multi-pathway study, age-related differences, dermal contact, exposure, children, longitudinal study, human exposure, insecticides, pesticide residues, gender-related variability, environmental toxicant, neurotixics, biological markers, dietary exposure, dust , agricultural community, exposure assessment, human health risk, organophosphate pesticides

Progress and Final Reports:

  • 2002
  • 2003
  • 2004 Progress Report
  • 2005 Progress Report
  • 2006 Progress Report
  • 2007 Progress Report
  • 2008
  • 2009 Progress Report
  • Final Report