The US Food Quality Protection Act--policy implications of variability and consumer risk.

The passage of the Food Quality Protection Act (FQPA) in August of 1996 increased the role of risk assessment in the decision-making process of the US Environmental Protection Agency (EPA). Although the law and guidance issued by the EPA provide for more sophisticated risk assessments, the databases for many chemicals may not be robust enough for such data-sensitive analyses. FQPA mandated a major change in how the EPA evaluates the safety of pesticides. This change was immediate, without provision for a phase-in period. Consequently, the EPA is still in the process of learning how to evaluate pesticides under the new paradigm. The EPA's task was further compounded by the lack of scientifically tested methodologies for evaluating aggregate and cumulative risk, as required under the new law. Clearly, the EPA is still in a state of transition between evaluating aggregate and cumulative risks to pesticides and evaluating them one chemical and one exposure route at a time. In all likelihood, the transition period will continue as the discipline of risk assessment develops the mental constructs and computational methodologies to fulfil the requirements of the law. In this interim period, therefore, policies are needed so the regulators and the regulated industry know what is currently acceptable, and how the EPA's thinking is evolving.

U.S. market basket study to determine residues of the insecticide chlorpyrifos.

A market basket study was conducted to measure residues of the insecticide chlorpyrifos in samples of apples, applesauce, apple juice, fresh orange juice, tomatoes, peanut butter, whole milk, ground beef, and pork sausage collected during a 12-month period from 200 grocery stores across the United States. Approximately 90% of the samples contained no detectable levels of chlorpyrifos, and all residues detected were below tolerances, the legal limits for the United States. No values greater than the limit of quantitation (LOQ) were found in applesauce (LOQ = 0.008 ppm), apple juice (LOQ = 0.003 ppm), whole milk (LOQ = 0.006 ppm), ground beef (LOQ = 0.005 ppm), or pork sausage (LOQ = 0.007 ppm) samples. Only one fresh orange juice sample contained residues greater than the LOQ at 0.015 ppm. Only about 20% of the apples (maximum = 0.052 ppm), 20% of the tomato samples (maximum = 0.058 ppm), and 50% of the peanut butter samples (maximum = 0.021 ppm) contained quantifiable residues.

Development of a Dietary Exposure Potential Model for evaluating dietary exposure to chemical residues in food.

The Dietary Exposure Potential Model (DEPM) is a computer-based model developed for estimating dietary exposure to chemical residues in food. The DEPM is based on food consumption data from the 1987-1988 Nationwide Food Consumption Survey (NFCS) administered by the United States Department of Agriculture (USDA) and on residue data from government-sponsored monitoring programs. Foods reported in the NFCS were categorized into exposure core foods (ECFs). A computer program for DOS-based personal computers was developed to link consumption of the ECFs with residue values observed in the foods. The data files utilized by the DEPM were designed in dBASE IV with FoxPro for Windows applications programs for queries and reporting. The program calculates exposure estimates for categories of core foods, such as grain dishes, fruits, or vegetables; for individual core foods, such as wheat and apple combination dishes; and for individual foods, such as apples or carrots. The program, residue summary databases, and core food consumption database permit the analyst to evaluate potential exposure of several population groups to various chemicals via the diet. The DEPM is not intended for risk assessments, but is a suitable tool for identifying data gaps and establishing priorities for research, and for identifying potentially significant foods for human exposure monitoring.