s a sweeping new federal law governing pesticide usage goes into effect in coming years, some farmers, particularly those who produce so-called minor crops, may no longer be able to use pesticides on which they’ve come to rely.
While it remains unclear exactly how the Food Quality Protection Act of 1996, often known as FQPA, will affect American agriculture, it appears the legislation will restrict or eliminate the use of some pesticides, says Dr. Turner Sutton, a professor in the department of plant pathology. Sutton is one of a number of College of Agriculture and Life Sciences faculty members who have been working to try to ensure that FQPA does not impose undue hardship on farmers.
The Food Quality Protection Act tells the federal Environmental Protection Agency how it is to go about regulating the use of pesticides by farmers, in particular how the EPA is to determine how much pesticide residue will be allowed on agricultural products. The new legislation resolves a potentially vexing problem for farmers, what had come to be known as the Delaney paradox.
The Delaney paradox stems from a section of the law that the FQPA replaces; that section is known as the Delaney clause. The old law specified how much pesticide residue was allowed on raw agricultural commodities. It also said that if any residue of a pesticide that had been shown to be a carcinogen became concentrated when a commodity was processed, use of the pesticide was banned on the crop from which the processed food was made. The Delaney clause required that a pesticide be banned even if residues were so small that any risk from consuming the processed food was considered negligible. The clause had the effect of prohibiting the use of pesticides on some crops even though there was no clear danger from the use.
The FQPA resolves the Delaney paradox by requiring the same health-based safety standards for pesticide residues on all foods, whether processed or raw. The new law also directs the EPA to review pesticide residue standards for all pesticides and describes the criteria the agency is to use in setting new standards. These are the provisions of the new law that are making farmers nervous.
ccording to the new law, the EPA is to set maximum allowable pesticide residue levels, or tolerances, by determining the level at which there is "a reasonable certainty that no harm will result from aggregate exposure" to the residue. In determining how much residue is safe, the EPA is to consider exposure to pesticide residues both in food and in drinking water. The EPA is also to take into consideration the special sensitivity of children to pesticides. Children eat proportionally more fruits and vegetables, Sutton explains, and may as a result consume proportionally more pesticide residue.
In order to ensure that a residue is safe for children and account for the uncertainty of data relative to children, the EPA may increase what otherwise might be considered a safe residue tolerance by a factor of 10. In other words, the initial tolerance, or amount of pesticide residue allowed on a particular commodity, may have been set at 2 parts per million. To ensure this standard is safe for children, the EPA may decrease the tolerance to .2 parts per million.
The FQPA also includes provisions for endocrine disruption testing and gives the EPA authority to require that pesticide manufacturers provide data on their products, including data on potential endocrine effects.
Various chemicals are thought to disrupt the endocrine systems of humans and animals. The endocrine system is made up of various glands that synthesize and secrete hormones, which regulate a wide range of biological processes. Some scientists have proposed that various chemicals in the environment may be disrupting the endocrine activity of humans and animals. The FQPA requires the EPA to develop an Endocrine Disrupter Screening Program designed to detect and characterize the endocrine activity of pesticides and other chemicals.
The new law requires the EPA by 2006 to re-evaluate pesticide residue tolerances for all pesticides. It is unclear what these re-evaluations will mean to farmers. Sutton points out, for example, that the FQPA requires the EPA when developing new tolerances to consider aggregate exposure of all pesticides with a common method of toxicity. This part of the new law seems particularly uncertain and is most likely to affect minor crops, Sutton adds.
In the past, he explains, the risk posed by an individual pesticide alone was considered when determining the residue tolerance for that pesticide on a particular commodity. If 10 pesticides were registered for use on apples, the risk of each was considered individually in determining individual residue tolerances. Now, the risk that all 10 pose collectively will be considered in determining tolerances for each.
Sutton said it is still unclear how tolerances for individual pesticides will be determined if, as seems likely, the collective risk of all the pesticides registered for use on a particular crop is determined to be too high. In such a situation, the process of determining tolerances for individual pesticides may be political and involve horse trading among the companies that produce the various pesticides.
Chemical companies will probably try to protect their biggest markets, perhaps giving up registrations for pesticide uses where sales are relatively low. Pesticide sales tend to be lower for use on minor crops (such as apples in North Carolina), so growers of minor crops may lose access to some pesticides.
s it assesses the risks of various pesticides and determines residue tolerances, the EPA is to consider the actual exposure to residues on various foods and the percent of a crop treated with a particular pesticide. College of Agriculture and Life Sciences faculty members are helping to educate EPA policy makers in this area by developing crop profiles that describe how pesticides are used in North Carolina.
Sutton says the effort to develop crop profiles began two years ago, when North Carolina Commissioner of Agriculture Jim Graham asked Dean Jim Oblinger of the College of Agriculture and Life Sciences for help in responding to EPA requests for information about pesticide use in North Carolina and in identifying the commodities most likely to be impacted by the FQPA. Dean Oblinger asked Sutton and Dr. Sterling Southern, North Carolina Cooperative Extension Service leader in the department of entomology, to serve as co-chairs of a committee formed to develop crop profiles.
Based on grower surveys, the crop profiles describe actual pesticide usage in North Carolina. Sutton says data on actual usage is important because of the aggregate exposure assessment that will be used in determining new residue tolerances. Without actual usage data, the EPA must assume in developing new residue tolerances that the maximum allowable amount of all pesticides registered for use on a particular crop is, in fact, used. Sutton said actual use is usually considerably lower than potential use.
Faculty members in the departments of plant pathology, entomology, forestry, horticultural science and crop science were asked to chair committees charged with developing profiles for the pesticide use in North Carolina. In all, 30 profiles have or are being developed. They cover crops from apples to watermelons and include pesticide use for public health and to control residential and structural pests. Twenty-six faculty members served as chairs of profile committees.
The profiles are available on the World Wide Web at http://ipmwww.ncsu.edu/ncpiap/cropprof.htm. Stephen J. Toth, entomology Extension specialist, and Dr. Ron Stinner, professor in the department of entomology, were instrumental in developing a College crop profile Web site as well as a similar national profile Web site for the U.S. Department of Agriculture.
In addition, Dr. Mike Linker, the College’s Integrated Pest Management coordinator, has served as a North Carolina representative on a national Tolerance Reassessment Action Committee, which addressed policy issues related to the FQPA. And a number of other faculty members have served on commodity-based committees charged with looking at how farmers may deal with the loss of pesticides until new pesticides become available. Faculty members have also been invited to give seminars to EPA personnel on North Carolina pesticide uses and needs.
While the potential loss of pesticides on which farmers now depend is the dark side of the FQPA picture, there may be a bright side. The expected loss of some pesticides appears to have spurred chemical companies to develop new pesticides, Sutton says.
"I see more activity now [aimed at developing new pesticides] than at any time in my career," Sutton says.
The development of new products will present yet another challenge to the College, Sutton believes. He explains that many of the new products being developed are less forgiving than the pesticides they will replace. They must be applied, for example, with more precise timing. If not applied during what can be a small window of opportunity, many of these new products will do little good.
"There will be a challenge to Extension particularly to educate growers how to use these new materials," Sutton says.
He adds that at the same time growers are learning how to use new products and dealing with new residue tolerances for old products, the public will continue to expect fresh, blemish-free produce and other agricultural products all year long.
"It’s going to be an interesting time," Sutton says. "There will be some real challenges for us."