Pesticide Residues in Foods
Most of the food produced for human consumption is grown using pesticides. Chemical control of weeds, insects, fungi, and rodents has enabled agricultural productivity and intensity to increase. However, these economic benefits are not without their risks to human and environmental health. Small amounts of some pesticides may remain as residues on fruits, vegetables, grains, and other foods. If exposures are great enough, many pesticides may cause harmful health effects, including delayed or altered development, cancer, acute and chronic injury to the nervous systems, lung damage, reproductive dysfunction, and possibly dysfunction of the endocrine (hormone) and immune systems.32-33
Children's exposures to pesticide residues may be relatively higher than those of most adults. Pound for pound, children generally eat more than adults, and they may be exposed more heavily to certain pesticides because they consume a diet different from that of adults.34 For instance, children typically consume larger quantities of applesauce, milk, and orange juice per pound of body weight.
Protecting the food supply from harmful levels of pesticide residues requires the ongoing attention of government agencies, pesticide producers, and pesticide users. The U.S. Department of Agriculture (USDA) collects annual data on pesticide residues in food. Among the foods sampled by the USDA's Pesticide Data Program in recent years are several that are important parts of children's diets, including apples, apple juice, bananas, carrots, green beans, orange juice, peaches, pears, potatoes, and tomatoes. EPA evaluates the safety of all new and existing pesticides and restricts pesticide use to those applications that do not pose unacceptable human health or ecological risks.
Pesticides are not the only contaminants in food that may affect children's health adversely. Industrial contaminants (such as dioxins, PCBs, and mercury), microbial contaminants (such as E. coli), and natural contaminants (such as aflatoxin) also can be found in foods. The Pesticide Data Program does not analyze foods for the presence of these types of contaminants, although other government programs monitor for some of them.
The chart on the following page displays the percentage of foods with detectable pesticide residues reported by the PDP from 1994 to 1998.35-36 This measure is a surrogate for children's exposure to pesticides in foods: If the frequency of detectable levels of pesticides in foods decreases, it is likely that exposures will decrease. However, this measure does not account for many additional factors that affect the risk to children. For example, some pesticides may pose greater risks to children than others do; residues on some foods may pose greater risks than residues on other foods due to differences in amounts consumed. For some pesticides, residues at levels below detection limits may pose important risks, while for other pesticides detectable levels of residues may not pose a significant health concern. In addition, year-to-year changes in the percentage of samples with detectable pesticide residues may be affected by changes in the selection of foods that are sampled each year.
- In 1994, 62 percent of all food samples tested by the U.S. Department of Agriculture's Pesticide Data Program (PDP) had detectable levels of at least one pesticide. The proportion of samples with detections increased to 68 percent in 1996, then declined to 55 percent in 1998.
- In 1998, 29 percent of samples had detectable levels of multiple pesticides, compared with 36 percent in 1994. During the same period, the proportion of samples with detectable levels of a single pesticide remained relatively constant.
- PDP data from 1994-96 were further evaluated for the presence of pesticides in 19 foods frequently eaten by children. This analysis focused on detections of carcinogenic and neurotoxic pesticides. Twenty-five percent of the samples had detectable levels of carcinogenic pesticides, and 34 percent had detectable levels of neurotoxic pesticides (not shown).
- Each year, less than 0.2 percent of all sampled foods had residues that violated established tolerances. A tolerance is the amount of pesticide residue legally allowed to remain on a food commodity.