1999 Progress Report: Total Organophosphours (Op) Pesticide Exposure Among Children in Urban and Rural Environments

EPA Grant Number: R825171
Title: Total Organophosphours (Op) Pesticide Exposure Among Children in Urban and Rural Environments
Investigators: Fenske, Richard
Current Investigators: Fenske, Richard , Lu, Chensheng (Alex)
Institution: University of Washington
Current Institution: University of Washington - Seattle
EPA Project Officer: Hahn, Intaek
Project Period: September 25, 1996 through September 24, 1999 (Extended to September 30, 2000)
Project Period Covered by this Report: September 25, 1998 through September 24, 1999
Project Amount: $600,145
RFA: Exposure of Children to Pesticides (1996) RFA Text |  Recipients Lists
Research Category: Pesticides , Children's Health , Health Effects , Human Health , Health , Safer Chemicals

Objective:

The objectives of this research project are to: (1) characterize geographic, temporal, age-related, and gender-related variability in total organophosphorus (OP) pesticide exposures in children; and (2) determine the relative contributions of environmental sources to total OP pesticide body burden in children.

Progress Summary:

Rural Longitudinal Biomonitoring Study. This phase of the study was designed to provide a picture of the long-term OP exposure patterns seen in children living in a rural agricultural area. The goal was to collect a spot urine sample every other week over the course of a year from each child (about 26 samples). Subjects (57 children from 52 families) were recruited from a Woman, Infants, and Children (WIC) clinic in Wenatchee, WA, and ranged from age 2 to 5. All samples were collected over the period from December 1997 through September 1999. Due largely to the unavailability of participants, samples were collected from 10 days to 3 months apart, and children gave from 1 to 27 samples.

Preliminary findings suggest that there is a time-related variation in children's exposure to OP pesticides. More OP breakdown products were found in urine during the spray period (April-June) than the nonspray period. No significant difference was found in the exposure received by males and females. Younger children (2-4 years) appear to have higher exposure than older children (5-6 years) to ethyl OPs, but there was not a significant difference with age for methyl OP pesticides.

Urban Cross-Sectional Biomonitoring Study. This phase of the study was designed to gather data on the level of OP breakdown products found in children living in urban and suburban areas. To accomplish this, we collected a spot urine sample from each child two different times in the higher pesticide use season (late spring/early summer 1998 and fall 1998). Samples were collected from 110 children?58 from a WIC clinic (South Seattle area) and 52 from a pediatric clinic (North Seattle area).

We did not find any associations between OP pesticide exposure and season (summer and fall), child's age, or gender. In other words, boys and girls with different ages had approximately the same amount of OP pesticide breakdown products in their urine in summer and fall. We found that some children had higher levels when their parents reported the use of pesticides in the yard/garden. However, this association was not strong enough that we would make a firm conclusion regarding this relationship. We found that children living in the greater Seattle area had lower levels of OP pesticide breakdown products in urine than children living in agricultural communities. Children living in agricultural communities may be more exposed to OPs because their parents often work in jobs where pesticides are used, and they typically live close to orchards.

Exposure Pathway Study. This phase of the study was designed to help us determine which OP pathways are important contributors to exposure for families living in both agricultural and nonagricultural communities. A total of 13 families with higher potential for OP exposure participated?6 were from the rural longitudinal study population and 7 from the urban cross-sectional study. Participant homes were visited for a 2-3 day period once in early summer 1998 and again in fall 1998. The following samples were collected from the children in and around their homes:

Home Environment 24-hour indoor air, house dust, soil, indoor and outdoor toy wipes
Child's Diet Drinking water, 24-hour duplicate meal samples
Child Hand wipes, 4 spot urine samples covering 24 hours

Environmental samples were analyzed to look for the following OP pesticides: azinphos-methyl, chlorpyrifos, diazinon, dichlorvos, and phosmet.

We found OP pesticides in more than one type of sample that we collected from study homes, suggesting that children in the study may be exposed to OP pesticides from multiple sources. Because the exposure patterns varied to a great extent, we were not able to identify a single source that contributes the most OP pesticide exposure to children in the study. We found OP pesticide breakdown products in the urine samples. Although this suggests that some of the OP pesticides that were in participating children's diets and environment may have been absorbed into their bodies, these levels were considered very low. Similar to the urban cross-sectional study, we did not find any associations between OP pesticide exposure and season (summer and fall), child's age, or gender.

Future Activities:

More detailed data analysis for all phases of the study is the primary remaining task.


Journal Articles on this Report : 1 Displayed | Download in RIS Format

Other project views: All 16 publications 4 publications in selected types All 4 journal articles
Type Citation Project Document Sources
Journal Article Moate TF, Lu C, Fenske RA, Hahne RMA, Kalman DA. Improved cleanup and determination of dialkyl phosphates in the urine of children exposed to organophosphorus insecticides. Journal of Analytical Toxicology 1999;23(4):230-236. R825171 (1999)
R825171 (2000)
R826886 (2000)
R826886C004 (2001)
  • Abstract from PubMed
  • Supplemental Keywords:

    sex, modeling, monitoring, analytical, measurement methods, Pacific Northwest, EPA Region 10, agriculture, pesticides, exposure, human health., RFA, Health, Scientific Discipline, Air, Toxics, air toxics, pesticides, Risk Assessments, Susceptibility/Sensitive Population/Genetic Susceptibility, Biochemistry, Children's Health, genetic susceptability, pesticide exposure, rural communities, urban air, monitoring, sensitive populations, multi-pathway study, organophosphates, age-related differences, dermal contact, exposure, children, gender-related variability, human exposure, insecticides, pesticide residues, environmental toxicant, biological markers, dietary exposure, dust , agricultural community, exposure assessment, organophosphate pesticides

    Relevant Websites:

    http://depts.washington.edu/pnash/home.htm Exit EPA icon
    http://depts.washington.edu/envhlth/about/facultypage/fens_page.htmlExit EPA icon
    Synthesis Report of Research from EPA’s Science to Achieve Results (STAR) Grant Program: Feasibility of Estimating Pesticide Exposure and Dose in Children Using Biological Measurements (PDF) (42 pp, 3.87 MB)

    Progress and Final Reports:

    Original Abstract
  • 1997
  • 1998
  • 2000 Progress Report
  • Final