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COLLECTING URINE SAMPLES FROM YOUNG CHILDREN FOR PESTICIDE STUDIES
Citation:
Hu, Y., E. D. Pellizzari, J. H. Raymer, G G. Akland, J. B. Beach, J. T. Keever, D. Barr, L. Needham, B A. Schumacher, AND L J. Melnyk. COLLECTING URINE SAMPLES FROM YOUNG CHILDREN FOR PESTICIDE STUDIES. Presented at ISEA Annual Conference, Monterey, CA, October 24-27, 2000.
Impact/Purpose:
The purpose of this research is to reduce uncertainties in exposure assessments of young children by improving EPA's ability to measure exposures in the context of aggregate and cumulative exposure assessments. The general objective of this research is to support FQPA children's exposure assessment efforts by improving procedures and reducing uncertainty in measurements for dietary exposure of young children, a critically needed area for improved risk assessment. Specifically, this research will evaluate a protocol and companion model for measuring or otherwise assessing the combined dietary intake of a young child as influenced by pesticides, or other environmental contaminants, which contaminate their foods during the eating process (indirect ingestion exposure). This research will continue to develop the important factors which are needed to characterize excess intake of pesticides by young children. Specifically, the research will measure pesticide surface transfer efficiencies for food contacts with surfaces and eating activity patterns of young children that define the frequency of contacts with contaminated surfaces. A series of reports/products are anticipated by the end of FY05.
Description:
To estimate pesticide exposure for young children wearing diapers, a method for collecting urine samples for analysis of pesticide metabolites is needed. To find a practical method, two possibilities were investigated: (1) analysis of expressed urine from cotton diaper inserts and (2) analysis of the whole void extracted from the diaper (or other urine collection materials).
In the first study, the validity of using cotton gauze pads as diaper inserts to collect urine samples from young children was tested. Urine was spiked with a pesticide and four metabolites: 2,4-dichlorophenoxyacetic acid (which is mainly eliminated from urine unchanged), 3-phenoxybenzoic acid (a metabolite of synthetic pyrethroids), atrazine mercapturate (a metabolite of atrazine), malathion dicarboxylic acid (a metabolite of malathion) and 2-isopropyl-4-methyl-6-hydroxypyrimidine (a metabolite of diazinon). Aliquots of the spiked urine were added to the gauze pads and were expressed from the pads, using a syringe, immediately and after 1,2,4,8 and 24 hours to determine the impact of contact time on recovery. Expressed urine samples were then extracted and analyzed. The recoveries of target analytes from the expressed urine were within a range of 70-130%.
In the second study, potential urine collection materials such as cloth diaper, sanitary napkins, gel sorbers and clay were spiked with a list of 12 potential urinary metabolites of organophosphate and carbamate pesticides. The urine was extracted and analyzed. The recoveries for each tested material were determined and will be presented.