K-State Research and Extension

Q: I recently read a report on the produce that contains the highest pesticide residuals, and many were fruits/vegetables that I consume on a regular basis. Should I be concerned?
A: The issue of pesticide residue in food is quite controversial. Pesticides are used because they have beneficial properties in terms of crop production and yield. Pesticides are used by farmers to prevent fungal invasion, insect damage, and the growth of unwanted (and often poisonous) plants. This has a positive benefit in terms of public health because fungi, insects, and non-crop plants can contaminate crops with many natural toxins.
Pesticides are probably one of the most regulated chemical products used in the U.S. The EPA, FDA and USDA are among the fourteen separate regulatory bodies that govern pesticide use. Despite the many regulations, pesticide residues are found in our food supply. Because residues are an inevitable by-product of pesticide use, many of the current regulations are in place to address the public health implications of pesticide use. Therefore, there are very strict restrictions on the amount of pesticides residues that are allowed in food.
One of the regulations that is currently in place requires that pesticide manufacturers conduct toxicity testing on the pesticide before it can be permitted for use on products either directly or indirectly destined for human consumption (this includes animal feed). This toxicity testing not only determines the health effects of pesticides, but also the level at which there are no toxic effects on the most sensitive population (i.e. children and the elderly). This ‘No Toxic Effect Level’ (NOEL) becomes the basis for the permitted residue limit. The regulations set the permitted residue level at a level that is from 10 to 100 times lower than the NOEL. Furthermore, if a pesticide is tested and a NOEL cannot be determined, then it is unlikely to be permitted for use on food crops. This helps ensure that if a person, child or adult, eats a larger than normal amounts of a particular food, or several different foods with the same or similar pesticide residue, they will still not reach the level of exposure required for a toxic effect to occur, even if they are more sensitive than the general population.
Each year, the Environmental Working Group publishes the “Dirty Dozen” report of foods that test positive for pesticide residues. While these foods may show pesticide residue is present, the risk is negligible. The Environmental Protection Agency (EPA) tolerance levels for pesticide residues is protective of human health. Test results are at levels well below tolerances set by the EPA. Drs. Carl Winter and Josh Katz of the Department of Food Science and Technology at the University of California-Davis are leading experts in the issue of pesticide residues. In a peer-reviewed, scientific article in the prestigious Journal of Toxicology (2011) they state the following conclusions: “Exposures to the most commonly detected pesticides on the twelve commodities pose negligible risks to consumers. Substitution of organic forms of the twelve commodities for conventional forms does not result in any appreciable reduction of consumer risks. The methods used by the environmental advocacy group to rank commodities with respect to (potential) pesticide risks lacks scientific credibility.” To read the full article, please visit the following link: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3135239/.