Pesticides in foods

Pesticides are more closely regulated than other chemicals because pesticides are intentiaHy appHed in the environment, often repeatedly at relatively high rates. In the United States, pesticides are regulated under the federal Insecticide, fungicide and Rodenticide Act (EIERA), and residues from uses of pesticides in food or feed crops are regulated under Sections 408 and 409 of the federal food, Dmg and Cosmetics Act (EEDCA). 

Subdivision O guidelines for residue chemistry data were originally pubHshed by the EPA in 1982. These have been supplemented to improve the rate of acceptance by EPA reviewers of the many reports submitted by registrants in support of tolerances for pesticides in foods. The residue chemistry studies most frequently rejected include metaboHsm in plants, food processing (qv) studies, and studies on storage stabHity of residues in field samples (57). AH tolerances (maximum residue levels) estabHshed under FIFRA are Hsted in 40 CFR under Sections 180 for individual pesticides in/on raw agricultural commodities, 180 for exemptions from tolerances, 185 for processed foods, and 186 for animal feeds. 

Regulating Pesticides in Food The De/anej Paradox, Report of Board on Agriculture, Committee on Scientific and Regulatory Issues Underlying Pesticide Use Patterns and Agricultural Innovation, U.S. National Research Council, National Academy Press, Washington, D.C., 1987, 272 pp. 

P. A. Fenner-Crisp, "Risk Assessment Methods for Pesticides in Food and Drinking Water," Office of Pesticide Programs, U.S. Environmental Protection Agency, presented at the Florida Pesticide Review Council Meeting, July 7, 1989. 

From this analysis it is clear that in addition to their benefits, the use of pesticides in food production not only causes serious public health problems but also considerable damage to vital agricultural and natural ecosystems in the United States and world. A conservative estimate suggests that the environmental and social costs of pesticide use in the United States total about 4 billion each year. Worldwide the yearly environmental and public health costs are probably at least 100 billion. This is several times the 18 bllllon/yr spent on pesticides in the world. 

Stan H-J, Mrowetz D. 1983. Residue analysis of organophosphorus pesticides in food with 2-dimensional gas chromatography using capillary columns and flame photometric detection. J High Resol Chromatog Chromatog Comm 6 255-263. 

EPA. 1988d. Tolerances for pesticides in foods. Endosulfan. U.S. Environmental Protection Agency. Code of Eederal Regulations. 40 CER 185.2600. 

Several methods have been discussed for the determination of method limitations when evaluating procedures for the determination of pesticides in food. A brief comparison of the methods discussed for the determination of the detection and quantification limits of methods used for the analysis of food products can be found in Table 2. 

This practice went on until recently. Four hundred eighty-one formulations and compounds were included in the official list of pesticides permitted for use in agriculture from 1986-90 [14]. In 1990, the MPC and other health protocols were developed for only 127 pesticides in food products, 105 pesticides in bodies of water used for hygiene and drinking, 78 pesticides in fishery reservoirs, 31 pesticides in farm animal feed, 81 pesticides in the soil, and 119 pesticides in work zone air [1]. There were no MPCs for the remainder of the pesticides permitted for use and, according to existing rules, they should not have been used. Nevertheless, they were. 

Research on pesticides in food products carried out in 1965-66 in Khersonsk Oblast (Ukraine) detected HCH in 80% of vegetable product samples, and DDT in 74.3%o (in products of animal origin, these figures were 10%o and 93.8%), respectively). The daily diet of subjects from Group I intensity work contained 2.31 mg of DDT [A77]. 

Regulating Pesticides in Food. The Delaney Paradox. Wash. (D.C.) Acad, press, 1987. 272 pp. 

The second milestone event in the USA in the 1990s was passage of the Food Quality Protection Act (FQPA) in 1996. The goal of the FQPA was to assure a reasonable certainty of no harm as a result of exposure to pesticides for all US population groups. The FQPA incorporated into federal law the major recommendations of the 1993 National Academy of Sciences (NAS)/NRC report, as well as the recommendations of a 1987 NAS/NRC report entitled Regulating Pesticides in Food The Delaney Paradox (National Research Council, 1987). 

National Research Council (1987). Regulating Pesticides in Food The Delaney Paradox. National Academy Press, Washington, DC. 

US Environmental Protection Agency (20002). OPP Revised OP Risk Assessment -Cumulative Risk From Pesticides in Foods. l.C.l—1.C.24. 

Tolerances for Pesticides in Food (Hydrogen Cyanide) 50 - 200 ppm 40CFR 185.3600 EPA 1975b... 

Stan HJ, Mrowetz D. 1983. Residue analysis of pesticides in food by 2 dimensional gas chromatography with capillary columns and parallel detection with flame photometric and electron capture detection. J Chromatogr 279(0) 173-188. 

Since the last part of the 20th Century, the issue of pesticides in foods has generated considerable public concern and debate. Pesticides are chemicals designed specifically for their toxicological effects on target pests, such as insects, weeds, and plant diseases. Public awareness that such chemicals are commonly detected in the food supply as residues contributes greatly to the debate. 

Contemporary risk assessment practices for pesticides in foods require far more data than simply the residue levels evaluated in government monitoring programs. Exposure to pesticides is determined by multiplying the residue levels on food by the amount of the food item consumed once determined, exposure is compared with standard toxicological criteria derived from animal toxicology studies to determine the acceptability of the exposure. 

In the calculation of chronic risks from pesticides in foods, the EPA frequently uses a deterministic approach to yield the theoretical maximum residue contribution (TMRC) for a pesticide. This value represents the maximum legal exposure to a pesticide, and assumes that ... 

Most of the analytical methods for the analysis of pesticides in food are based on instrumental approaches based on chromatography coupled to mass spectrometry. However, a great effort of development has been paid to develop rapid screening methods based on biological methods, such as, enzyme linked immunosorbent assays (ELISA). 

Successfully examples of applications have been reported for the analysis of pesticides in food using PLE during the extraction step [138-147]. Research had been conducted to optimize the effects of extraction temperature, number of extraction cycles, and various extraction solvent mixture compositions on the extraction effectiveness and recoveries of pesticides fi om food. Besides, cleanup sorbent material(s) can also be imbedded in the extraction cells so that cleanup can also be processed simultaneously with extraction. Although it has the advantages of low solvent consumption and short extraction period, the initial cost is high, large amount of unwanted matrix substances are co-extracted and some unstable compounds, such as endrin yielded low recoveries. 

R.D. Mortimer, B.A. Dawson, Using F-19 Nmr for trace analysis of fluorinated pesticides in food-products, J. Agric. Food. Chem. 39 (1991) 1781-1785. 

Once the public had their attention drawn to the chemicals to which they were being exposed, it is hardly surprising that they formd plenty to worry about. There are 75,000-90,000 synthetic chemicals in use, many of which have never been a subject of intensive toxicological testing. Even fewer have been subject to thorough enviromnental impact assessments. These facts were emphasised to the public, especially by some of the NGOs. Virtually, the only time members of the public heard or read about individual chemicals in the media was when they were mentioned as part of scare stories— pesticides in food, contaminants in tap and botded water, side effects of drugs and so... 

Jedlicka, V, Pasek, A. Gola, J. (1958) Pesticides in foods. III. Acrylonitrile as a food insecticide. J. Hyg. Epidemiol. Microbiol. Immunol., 1, 116-125... 

Table 9 HPLC Determination of Urea Pesticides in Food Samples...

The successful combination of mass spectrometry with gas chromatography (GC-MS) and, subsequently, with liquid chromatography (HPLC-MS) allowed not only the determination of urea pesticides in food but also the identification of their residues at trace level. Mass spectrometry is a technique that can be used as a general detector, with cyclic scanning. The selectivity and sensibility of analysis can be enhanced using characteristic ions of the molecule, with selected ion monitoring (SIM). Urea pesticides have been determined by HPLC-MS directly (175-180), without the thermal instability problems of GC analysis. 

A De Kok, M Hiemstra, CP Vreeter. Optimization of the postcolumn hydrolysis reaction on solid phases for the routine high-performance liquid chromatographic of N-methylcarbamate pesticides in food products. J Chromatogr 507 459-472, 1990. 

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