Grantee Research Project Results
2002 Progress Report: Longitudinal Study of Children's Exposure to Permethrin
EPA Grant Number: R829397Title: Longitudinal Study of Children's Exposure to Permethrin
Investigators: Hu, Ye A. , Akland, Gerald G. , Raymer, James H.
Current Investigators: Raymer, James H. , Hu, Ye A. , Michael, L. C. , Studabaker, W.
Institution: Desert Research Institute
EPA Project Officer: Aja, Hayley
Project Period: February 18, 2002 through February 17, 2005 (Extended to July 17, 2006)
Project Period Covered by this Report: February 18, 2002 through February 17, 2003
Project Amount: $754,664
RFA: Children's Vulnerability to Toxic Substances in the Environment (2001) RFA Text | Recipients Lists
Research Category: Environmental Justice , Human Health , Children's Health
Objective:
The specific objectives of this research project are to: (1) investigate the time course of the redistribution of pyrethroid pesticides in various media following application and factors affecting the redistribution; (2) investigate the functional relationships across time between environmental media, personal measurements, and biological media; (3) estimate aggregate exposure after application and the importance of each exposure pathway; and (4) investigate the difference between the time course of pyrethroid pesticide metabolism between adults and children. To achieve the objectives, we aim to recruit and follow 15 homes that use pyrethroid pesticides indoors and with stay-at-home children younger than 3 years old. Each of the homes will be followed intensively for 7 days after application. Then they will be followed once a week in the first month after application and every other month in the following 11 months. Environmental samples, food samples, personal samples (hand wipes, whole body dosimeter), and urine samples will be collected from children and one stay-at-home parent. The samples will be analyzed in our laboratory following standard operating procedures and analysis protocols. Data will be analyzed, and models will be developed to meet the objectives.
Progress Summary:
In Year 1 of the project, we focused our attention on the preparation for field sample collection and laboratory analysis. Our specific accomplishments are listed below:
• Finalized questionnaires and diaries and obtained Institutional Review Board (IRB) approval.
• Prepared all the necessary standard operation procedures (SOPs) needed for this study, including seven for field collection and six for laboratory analysis;
• Assembled and trained field teams for sample collection;
• Programmed information shell to key in (or load) field data, diary data, analytical data, and chain of custody information.
• Developed a method to analyze target pyrethroid metabolite in disposable diapers and examined the percent recoveries in other media.
• Recruited 11 subjects into the study and started sample collection.
The highlight of the accomplishments of Year 1 is the development of a method to analyze target pyrethroid metabolites in disposable diapers with polyacrylate polymers. Because about 200-300 urine samples are expected to be collected from young children under age 3 and analyzed for pyrethroid metabolites, it is highly desirable to develop a convenient and low-cost method to analyze urinary metabolites. Disposable diapers are widely used in the United States and many other areas of the world; therefore, they are an ideal media for urine collection. However, disposable diapers normally contain superabsorbent polymers that. make the extraction and analysis of urine very difficult. Although gauze pads can be attached to the diaper to collect urine samples, the problem with the gauze method is that only 3-12 mL of urine can be expressed, and as much as 170 mL of urine produced from normal 1-3 year old children are not fully used. To overcome the problem, we used salt solutions to collapse the polyacrylate polymer in the disposable diapers. Once the polymer collapses, much of the absorbed liquid is released, thus recovering the analytes. High performance liquid chromatography interfaced with tandem mass spectrometry was used to analyze three major urinary pyrethroid metabolites, including 3-(2,2-Dichlorovinyl)-2,2-dimethyl-(1-cyclo-propane) carboxylic acid (DCCA), 3-(2,2-Dibromovinyl)-2,2dimethyl-(1-cyclo-propane) carboxylic acid (DBCA), and 3-phenoxybenzoic acid (3-PBA). Most of the percent recoveries were in the range of 63 percent–133 percent with good precision (RSD < 22 percent). The limit of detection was 0.1 µg/L for all the metabolites. The storage stability test indicated that the tested pyrethroid metabolites were stable in polyacrylate-containing disposable diapers for at least 72 hours.
Future Activities:
The major goal of Year 2 is to collect and analyze 90 percent of the field samples. The remaining 10 percent of the samples are expected to be collected and analyzed in the first one-half of Year 3. So far, 11 subjects have been recruited, achieving 73 percent of the original goal of 15 households. In Year 2, we will continue to recruit four more subjects to meet the goal. With SOPs in place for field sample collection and sample analysis, we do not expect major difficulties in sample collection and analysis. In the second year, we also will start to assemble the database and build preliminary models. Final statistical analysis and modeling, however, will be performed in Year 3.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
| Other project views: | All 9 publications | 4 publications in selected types | All 4 journal articles |
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Hu Y, Beach J, Raymer J, Gardner M. Disposable diaper to collect urine samples from young children for pyrethroid pesticide studies. Journal of Exposure Analysis and Environmental Epidemiology 2004;14(5):378-384. |
R829397 (2002) R829397 (2003) R829397 (2004) R829397 (Final) |
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Supplemental Keywords:
pyrethroid pesticides, children, longitudinal, disposable diapers, exposure modeling., RFA, Scientific Discipline, Health, Health Risk Assessment, Chemistry, Risk Assessments, Disease & Cumulative Effects, Children's Health, Biology, multi-pathway study, permethrin, pesticides, functional relationships, urinary metabolite, exposure, children, longitudinal study, body dosimeter, human exposure, exposure pathways, metabolism, exposure assessmentProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.