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Project Details

Infant-Toddler Exposure Study

Photo of toddler on floor
Project Summary: 

The Infant-Toddler Exposure Study was a collaborative project with U.S. Environmental Protection Agency to examine how babies and toddlers are exposed to pesticides by measuring pesticide levels on their clothes, hands and toys; in the dust in their homes; and in their urine. We also videotaped the children to learn about their exposure-related behaviors, such as putting things in their mouths.

Researchers are studying the sources and extent of pesticide exposure for 6- to 24-month-old children of farmworker parents; levels of pesticide contamination in several kinds of environmental samples from farmworker children’s homes; and the relationship of pesticide levels in homes (i.e., in house dust, etc.) to biological measures of exposure (i.e., organophosphate pesticide metabolites in urine) in young children.

Main Findings: 
  • Pesticides were detected more frequently in house dust, surface wipes, and clothing than other media
  • Chlorpyrifos, diazinon, chlorthal-dimethyl, and cis- and trans-permethrin detected in 90-100% of house dust, surface wipes, and clothing samples
  • Pesticide residues on clothing (union suits and socks) were consistently higher in the older group of children (21-27 months) compared to the younger children (5-11 months)
  • Child Activity Timeline, a low-literacy instrument based on pictures, was successfully used by participants and has been implemented in recent studies

Study findings suggest that higher concentrations of the most frequently detected analytes on the clothing of the older age group may be attributed to the fact that toddlers are more actively walking, running, crawling, and playing than younger children, and are thus potentially more exposed to pesticide residues from residential surfaces.

Policy, Practice or Research Impacts: 

This study helped identify the most prevalent pesticides present in Salinas Valley farmworker homes, drew attention to the important role of house dust as a source for indoor exposure to environmental contaminants, and shed light on differences in exposure behaviors between infants and toddlers.

Project Type: 
Contact Person: 
Dr. Asa Bradman
Contact Person's Email Address:
Center for Environmental Research and Children's Health (CERCH)
Principal Investigators: 
Dr. Brenda Eskenazi
Research Publications and Reports: 

See publications on environmental exposures on CERCH's website:

The National Institute for Environmental Health Sciences (NIEHS), Environmental Protection Agency (EPA)
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