Innovative Assessment of Household Pesticide Exposure Using Linkage to EPA Databases

Abstract

ISEE-457 Objective: Household pesticide use has been associated with an increased risk of childhood leukemia in case-control studies. These results are based largely on self-reported pesticide use that is limited by potential recall bias and a lack of information on active ingredients. Here we describe a method for objectively characterizing household pesticide exposure by linking EPA registration numbers collected from products stored in the homes to publicly available EPA databases, thus allowing for identification of active ingredients, chemical formulation, intended target pest, and potential toxicity for each product. Material and Methods: Participants enrolled in the Northern California Childhood Leukemia Study (NCCLS), a case-control study, who were less than 8 years of age and residentially stable were eligible for a follow-up interview in which interviewers conducted an inventory of pesticide products stored in the home. Among 367 households enrolled from 2001 to 2005, we obtained detailed information from respondents for 4045 products (mean number per household: 4.89; range: 0–27) including the EPA registration number, storage location, pest treated, method of application, location of use, who applied the product, and the time period and frequency of use. Results: EPA registration numbers were successfully linked to EPA databases for 3006 (74%) products of which 71% were insecticides and 17% herbicides. Pyrethrins (15.4%), glyphosate (6.8%), and permethrins (5.0%) were the most frequent active ingredients contained in the products found in the homes, usually in the form of pressurized liquids (40%) and ready-to-use solutions (24%). Conclusions: The information obtained from the EPA database will allow us to conduct analyses by specific active ingredients and toxicity characteristics of the products and will complement information obtained from self-reports and household dust sampling currently underway in the NCCLS.