Pesticide Residues in Processed Foods: Not a ... - ACS Publications

Chapter 11

Downloaded by NORTH CAROLINA STATE UNIV on September 30, 2012 | http://pubs.acs.org Publication Date: May 14, 1998 | doi: 10.1021/bk-1998-0683.ch011

Pesticide Residues in Processed Foods: Not a Food Safety Concern

E. R. Elkins, R. S. Lyon, and R. Jarman National Food Processors Association, 1401 New York Avenue, Suite 400, Washington, DC 20005 Residue analyses results indicate that residues of triazine herbicides are not a source of concern to the processed foods industry. As with all properly applied pesticides, no food safety concerns are warranted. A close examination of the FDA Residue Monitoring program data show no residues of cyanazine, atrazine, simazine or ametryn in 1992, 1993, or 1994 representing 76,973 samples. The NFPA database (6563 values) contains one positive value (0.04 ppm) for simazine in corn and one positive value for atrazine in wheat rough (0.05 ppm). Several general pesticide issues which continue to confront the industry include inadvertent spray residues, residue concentration in soil, illegal or unintentional use of unregistered or canceled materials, consumer expectations for residue-free products, pesticide use by foreign product sources, and pesticide standards in countries to which we export. These industry concerns are discussed. The National Food Processors Association (NFPA) has long been interested in the issue of pesticide residues on processed foods, or foods ready to eat. In 1960, we developed the NFPA Protective Screen Program. The objective of this program is the prevention of illegal or unnecessary residues in processed foods. The program, a set of detailed recommendations that have evolved from more than 25 years of experience in the operation of active programs that are helpful in the prevention of illegal or unnecessary residues, is published annually NFPA has been involved in research on pesticide residue chemistry, the influence of food processing operations that remove pesticide residues from foods, and the development and improvement of analytical methods for detection and quantitation of pesticide residues for more than forty years. Over the past eight years we have built and maintained a substantial pesticide residue 116

©1998 American Chemical Society In Triazine Herbicides: Risk Assessment; Ballantine, L., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1998.


117 database that includes over a million records, many on processed foods. We also maintain the capability of a risk assessment program using the EPA Dietary Risk Evaluation System (DRES) software. This research and the DRES program provides NFPA a sound basis for evaluation of current issues dealing with pesticide residues in food, and based on this experience, we can say that pesticide residues in processed foods are not a food safety concern. This includes the triazine herbicides; the subject of this book. The triazine herbicides have a long history. This class of herbicides includes atrazine, simazine, and cyanazine. Both cyanazine and atrazine control weeds by interrupting photosynthesis in susceptible weed species. Atrazine was first introduced in 1958 and provided farmers with the first effective alternative to cultivation and 2,4-D for the control of grasses and other weeds. Atrazine quickly became the leading herbicide applied to corn. Corn is both the largest and the highest value crop grown in the United States. According to USDA, farmers in the US produced 6.3 billion bushels of corn in 1993 with a farm-gate value of $16.6 billion. Corn production has increased significantly over the past forty years while the number of planted acres has declined, largely due to the increased productivity of the acres cultivated . Cyanazine was introduced to the corn market in 1971 and provides weed control similar to atrazine, but without limiting rotational crop options. Atrazine accounted for 55% of all the pounds of herbicides applied to corn in 1992, according to USDA. Most of these herbicides are used in combination with each other. Farmers tend to use herbicides that provide the most cost-effective weed control consistent with tillage practices and local weed pressures. Dietary Exposure-Processed Foods As we discuss, the commercial operations that remove pesticides from food keep in mind that the triazine herbicides are selective, pre-emergence and postemergence herbicides and one would not expect them to be present in foods. In general, recovery of the edible portion of a vegetable or fruit may involve husking, peeling, shelling or coring operations which effectively remove most of the pesticide with the discarded portions of the plant. Peas and corn are examples of foods in which pesticides seldom, if ever, come in contact with the edible portion. To illustrate the effect of commercial processing on pesticide residues on food we have selected tomatoes. Figures 1, 2, and 3 are flow charts showing unit operations in commercial processing that remove pesticides from tomatoes. These procedures are required in the processing of tomatoes and were not specifically designed to remove pesticide residues. Tomatoes are received in bulk trailer carriers and are usually processed the day received. The washing procedures are started immediately while the tomatoes are still in the bulk trailers or trucks. Tomato processing is very water-intensive using approximately 1000 gal. of water per ton of raw tomatoes. The raw tomatoes are moved by conveyor, while still being washed, to sorting tables where any rotten or unusable fruit is removed. Tomatoes are peeled by

In Triazine Herbicides: Risk Assessment; Ballantine, L., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1998.

. FreshWater

Unwashed Tomatoes ι , Washing Wash Water

ι Washed Tomatoes


FIG. 1-Flow Chart for Washed Tomatoes

Crushing

I Hot Break

Finisher ι Wet Pomance

1

I

1 Juice

I

Drying

Canned

Juice

Dry P o m a c e FIG. 2-Flow Chart for Canned Tomato Juice

W a s h e d Tomatoes

Peeled Tomatoes ι Tomato Peel

1

1 Canned Whole Tomatoes

Wet Pomace

Drying Dry P o m a c e FIG. 3-Flow Chart for Canned Whole Tomatoes In Triazine Herbicides: Risk Assessment; Ballantine, L., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1998.


119 either hot lye or steam as the washing procedure continues. After peeling, the tomatoes are subjected to additional sorting to remove unusable fruit. The finished products, whole tomatoes, tomato juice, tomato sauce, catsup, etc., are canned and retorted. The effects of processing on the residues of malathion and carbaryl in tomatoes have been reported (2). Washing, blanching and canning removed 99% of both residues from tomatoes. As with other processed foods, residues of triazine herbicides are not a source of concern and as with all properly applied pesticides, no food safety concerns are warranted. The NFPA pesticide residue database confirms this statement. The database includes residue data from the processed foods industry, FDA and USDA. Residue data on infant foods and adult foods eaten by infants that were obtained by USDA APHIS for FDA (3) are also a part of our database on pesticide residues. The data in this database substantiates the fact that pesticide residues in foods ready-to-eat are rare, and if found at all are at, or close to the quantitation limit of the method used. A close examination of the FDA database shows no residues of cyanazine, atrazine, simazine or ametryn in 1992,1993, or 1994 representing 76,973 samples. The NFPA database (6563 processed and raw values) contains one positive value (0.04 ppm) for simazine in raw, unprocessed corn and one positive value for atrazine in unprocessed wheat rough (0.05 ppm). The USDA residue program does not test for these herbicides. The available residue data clearly indicate that triazine herbicides do not present a food safety issue. Pesticide Issues of Concern While it is clear that pesticides in general and triazines in particular are not a food safety problem, legal and consumer demands raise a number of concerns for food processors. These concerns are not necessarily unique to food processors but remain as issues that can, and in some instances, have serious implications for the food processing industry. Loss of Pesticides. Pesticides are important and in many situations essential tools for producing a safe, abundant food supply. However, in a growing number of instances, pesticide uses on fruits and vegetables are being lost. Public health, environmental, and/or worker safety concerns result in the restriction or elimination of a pesticide's use. In addition, pesticide manufacturers/registrants find the costs of maintaining the registration of some products, particularly if their uses are significantly restricted, are not justified by the market for those products. The loss of these "minor use" pesticides can have a major impact on fruit and vegetable production. Pesticide uses are also affected by federal environmental statutes. The Clean Air Act Amendments of 1990 (CAAA), for example, establishes an inflexible standard for eliminating the use and production of chemicals in the United States that exceed the statuary limit for ozone depleting potential. Under the C A A A , methyl bromide production and use in the United States is slated to end in 2001. Unless efforts to change this outcome are successful, U.S.



120 agriculture and food processors will lose an extremely important pest control tool, U.S. producers will be placed at a competitive disadvantage with foreign producers, and exports of U.S. agricultural products may be significandy affected. The loss of methyl bromide is particularly problematic in that the availability of effective, practical alternatives is by no means certain. The application of the Federal Food, Drug, and Cosmetic Act (FFDCA) in evaluating the safety of pesticide residues in food directly affects the availability of pesticides. The strict interpretation of the Delaney clause of the FFDCA was a factor in accelerating the loss of pesticide uses. In Les v. Reilly the Ninth Circuit U.S. Court of Appeals ruled that the Delaney clause established a zero risk standard for pesticides that EPA determined induce cancer in humans or animals and concentrate in processed foods or animal feeds or are applied directly to processed foods. Passage of the Food Quality Protection Act of 1996 (FQPA) removed the application of the Delaney clause from pesticide registration decisions. However, FQPA raises other issues that may impact the availability of minor use pesticides. The actual significance of FQPA to the availability of pesticides will be determined as the U.S. Environmental Protection Agency (EPA) applies the new mandated requirements of the statute. Food processors' concerns over the loss of pesticide uses are for the most part the same as those of food producers. These include the reduced ability to deal with and the potential for increased pest resistance, the lack of acceptable alternative crop and product protection tools, limitations to the development and implementation of effective integrated pest management programs, increased production costs without true public health or environmental improvements, and the potential that the pesticides used to replace eliminated pesticides will cause more problems than they solve. Illegal Residues. Government and industry data show that illegal pesticide residues in either raw agricultural commodities or processed food products are rare, and more importantly do not pose an actual food safety concern in most instances. However, the presence of an illegal residue can subject a processed food product to government enforcement actions, large scale recalls by the processing company, and loss of consumer confidence in the product. With product loyalty and the investment in processing and introducing a product in the market place at stake, the presence of an illegal residue is a major concern for food processors. The problem food processors face is that an illegal residue can come from a number of sources. The most obvious, and fortunately, the least likely source of an illegal residue is the illegal use of a pesticide during crop production or in post-harvest applications. Food processors' application of the NFPA protective screen program or variations of it, is focused primarily on this source of illegal residues. Through close coordination with growers, product specifications, spray histories, and as a last resort, analytical monitoring, food processors are able to confirm legitimate pesticide applications are the norm. Appropriate and legal pesticide applications, however, can result in illegal pesticide residues that are more difficult to control. Previous legal use of persistent pesticides that have



121 been removed from domestic agricultural applications such as DDT and aldrin may leave soil residues which result in detectable residues in raw agricultural commodities. Also, crop rotations and changes in cropping over time may result in illegal pesticide residues that come from previous legal and totally justified pesticide applications. In some circumstances this source of illegal pesticide residues must be addressed with changes in the registration of particular pesticides. The international movement of food products, both raw commodities and finished products, present an increasingly complex array of problems. Despite growing efforts to harmonize pesticide residue tolerances, such as the ongoing programs among the United States, Canada, and Mexico, international uniformity in allowable pesticide uses and legal tolerances is far from complete. Raw agricultural commodities legally treated with a pesticide in an exporting country may not satisfy domestic pesticide standards. There are numerous examples of raw commodities being denied entry to the United States or entry being significantly delayed. Food processors' ability to identify and address potential problem pesticides on imported commodities is greatly affected by the degree of communication and oversight possible with foreign suppliers. The converse situation exists in exporting processed products. Food processors must pay particular attention to the requirements of the countries to which products are exported. Situations can develop virtually overnight that result in an exported product being prohibited from a foreign market. Another potential source of illegal residues of concern to food processors results from unintentional deposition of pesticides. Spray drift, natural processes, human error, and cross contamination of pesticides themselves are among the possible situations that may lead to the presence of an illegal residue. The ability to detect lower and lower levels of pesticide residues make these unintended and innocent sources of illegal residues even more problematic. It is to the credit of the domestic and international food production industry that the actual occurrence of illegal pesticide residues, particularly those that might be a real health issue, is minimal. However, experience has shown that illegal residues justify food processors attention and concern. Consumer Expectations. A fundamental concern faced by food processors is consumer perception and response to the safety and quality of their food products. Despite all the evidence that shows pesticide residues are not a food safety problem and the checks and balances throughout the food regulatory and production system, potential consumer doubt about their food is a major concern for the food producer. As the so-called "alar incident" demonstrated, consumer perception can have a profound economic impact on food processors as well as growers and a devastating impact on the credibility of our food safety system. Reports that consumers actually questioned whether apple juice needed to be treated as a hazardous waste because residues of alar might be present point to the need for a sustained and long term effort in consumer education and risk communication. However, such reports also demonstrate that food


122 processors must be aware of consumer concerns, no matter how scientifically or legally unjustified we think they are.


Conclusions Even though no food safety concern exists relative to triazine residues in processed or unprocessed foods there are still many issues that need to be addressed such as the loss of pesticides when no alternatives are available. Illegal residues and consumer expectations also are of concern. We need to continue developing methods for dealing with these concerns. Literature Cited (1) Judge, James J. The Almanac of the Canning, Freezing and Preserving Industry, Westminster, MD (2) Elkins, E.R. JAOAC Int. 1989, 72, pp 533-535. (3) Yess, N.J., Gunderson, E.L., & Roy, R.R. J. AOAC Int. 76, 492-507.


Pesticide Residues in Processed Foods: Not a ... - ACS Publications

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