In 1991, the United States Department of Agriculture (USDA) was charged with designing and implementing a program to collect data on pesticide residues in food. Responsibility for this program was given to the USDA Agricultural Marketing Service (AMS), which began operating the Pesticide Data Program (PDP) in May 1991. The data produced by PDP are reported in an annual summary. To date, PDP has tested 112 different commodities and over 450 different pesticides.

PDP data are used by the Environmental Protection Agency (EPA), the Food and Drug Administration, the USDA Economic Research Service and Foreign Agricultural Service, as well as groups within the private sector. EPA uses PDP data to prepare realistic pesticide dietary exposure assessments as part of its ongoing effort to implement the 1996 Food Quality Protection Act. The Government and agricultural community also use PDP data to examine pesticide practices and U.S. trade. PDP data have been helpful in identifying crops where alternative pest management practices are needed. PDP data are also useful in promoting export of U.S. commodities in a competitive global market and addressing food safety issues.

EPA data needs have increased following the passage of the 1996 Food Quality Protection Act (FQPA) and with EPA's use of sophisticated assessment models that require the scope and reliability of the extensive PDP database. Using PDP data, EPA has been able to prepare assessments that more accurately evaluate exposure to pesticide residues in the American diet.

In estimating the potential risks of pesticide residues in food, EPA uses a step-wise tiered approach. As a first step, EPA may use a "conservative" worst-case scenario and assume that a pesticide is applied to the fullest extent permitted by the pesticide label - on every acre of each approved crop and at the maximum rate and frequency allowed. EPA may also assume that residues on treated crops are present at the maximum allowed level. Exposure estimates based on such assumptions are likely to exceed actual exposure significantly. When an initial assessment indicates potential risk of concern, EPA refines its assessment using realistic exposure data. Refinements may include using data on the percent of a crop treated with a pesticide; studies of the effects of washing, cooking, processing, and storage; and residue monitoring data. This is when PDP data can be pivotal. PDP sampling procedures were designed to capture actual residues in the food supply as close as possible to the time of consumption.

PDP concentrates its efforts in providing better pesticide residue data on foods most consumed by children. This PDP policy is guided by the requirements of the 1996 Food Quality Protection Act and by recommendations made in 1993 by the National Academy of Sciences (NAS) in "Pesticides in the Diets of Infants and Children."

PDP is a Federal-State partnership. Program operations are carried out with the support of 10 States: California, Colorado, Florida, Maryland, Michigan, North Carolina, New York, Ohio, Texas, and Washington. Seven of those States provide laboratory testing services. One Federal laboratory, the USDA-AMS National Science Laboratory, provides specialized testing services. The AMS Monitoring Programs Division is responsible for administrative, sampling, technical, and database activities for PDP.