New challenges: Residential pesticide exposure assessment in the California Department of Pesticide Regulation, USA

Residential exposure assessment is in an early stage of development within many of the regulatory agencies responsible for pesticides, Some of the imp etus for residential assessment comes from the Food Quality Protection Act (FQPA), a federal law adopted in 1996 in the USA. The FQPA mandates that th e aggregate and cumulative risks from all nonoccupational sources of exposu re to similarly acting pesticides be assessed. The development of methods f or residential exposure assessment is therefore proceeding in tandem with m ethods for aggregate risk assessment. The California Department of Pesticid e Regulation (Cal DPR) regulates pesticides in the state of California much as the US EPA does at the national level. While Cal DPR is not explicitly bound by the federal law, it recognizes the importance of residential expos ure and of cumulative risk, and tries to harmonize its methods with those o f US EPA, Accordingly, Cal DPR is developing guidance for residential expos ure assessment. Some factors to consider are the following: (1) although th e end goal may be total exposure from all sources, in order to regulate the use of products it is necessary to have separate estimates of exposure fro m individual sources and routes; (2) probabilistic approaches will be used increasingly, and they must separate variability and uncertainty; (3) there is a critical need for data on residential use of pesticides, including th e frequency of mishaps and improper handling; (4) data are needed on long-t erm activity patterns of individuals, including residential and occupationa l history; (5) regulatory agencies need a way to identify and screen potent ial exposure scenarios, in order to streamline the risk assessment process. (C) 2001 British Occupational Hygiene Society. Published by Elsevier Scien ce Ltd. All rights reserved.