Pesticide-induced cancer

Dennis Avery estimates that less than 3% of all cancer deaths are caused by all the combined forms of environmental contamination and pollution. Both Avery and Bast and coauthors cite work by Dr. Robert Scheuplein of the FDA who specifically looked at the incidence of pesticide-induced cancer in relation to the total amount of cancer attributed to food. At the most, pesticides could account for 0.01% of food-related cancers, a topic we will address extensively in the next chapter. Many authors cite similar conclusions based on an often-quoted landmark epidemiological study on the causes of cancer, done by Doll and Peto in 1981 and published as the book The Carnes of Cancer. The authors studied cancer deaths in our country from the 1930s to the late 1970s, the precise period when the risk of pesticide-induced cancer would have been expected to peak as chemicals such as DDT were in heavy use during this period prior to the influence of Silent Spring. They concluded that 98-99% of can-... 

One major problem caused by Section 409 (c) (3) of the Federal Food, Drug and Cosmetic Act, commonly known as the Delaney Clause , which governed the registration of pesticides was the statement, No additive shall be deemed safe if it is found to induce cancer when ingested by man or animal,... . Dr Fred R. Shank, Director, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, in... 

Finally it should be noted that prior to the FQPA in 1996, the Delaney clause prohibited the establishment of tolerances or maximum allowable levels for food additives if it has been shown to induce cancer in human or animal. This is an important change in regulations because pesticide residues were considered as food additives. Because of the FQPA, pesticide residues are no longer regarded as food additives, and there is no prohibition against setting tolerances for carcinogens. 

Since its adoption, the 1938 law has been amended repeatedly, eventually extending the FDA s regulatory powers to pesticides and food additives. In 1958, the Delaney clause was incorporated into the law. This now controversial provision prohibits the approval of any food additive found to induce cancer in humans or animals. 

EPA establishes raw agricultural commodity (RAC) and food additive tolerances for pesticides on food. Carcinogenic pesticides may be registered and tolerances may be set for the raw agricultural commodity if the levels are safe however, if the concentration of a pesticide on food increases when it is processed, a food additive tolerance is required. The Delaney clause of FFDCA does not allow a food additive tolerance to be set, even if EPA believes it is safe, if the compound has been shown to induce cancer in man or animal. A narrow interpretation of the Delaney clause has prevented registration of new products in circumstances where the upper-bound risks were estimated to be much less than one in a million. 

If the RAC, which has been treated with a pesticide, is processed, and if the concentrations of the pesticide in the final form of the processed food are greater than the concentrations found in the RAC, then a food additive tolerance must be established under Section 409 of the FFDCA. Like the 408 RAC tolerance, a Section 409 food additive tolerance must be set at a level that is not unsafe. But over and above the basic requirement of safety. Section 409 prohibits establishing a food additive tolerance when the compound has been shown to induce cancer in man or animals. This prohibition is the Delaney clause. 

The Delaney clause can prevent the establishment of tolerances and the registration of pesticides. To explain the effect of the Delaney clause on registration, one can separate pesticides into two groups (1) where the pesticide has been shown to induce cancer in man or animal (an "oncogenic pesticide") and... 

New products, if shown to induce cancer in man or animals and if they need a 409 food additive tolerance, are kept off the market. This is true even if they replace older and less safe pesticides. No degree of demonstrated safety has led EPA to register oncogenic pesticides at this time. This is true even where the benefits of a new pesticide substantially outweigh the risks. The FIFRA risk-benefit part of the equation is not considered as part of the equation if an oncogenic food-use pesticide needs a 409 tolerance. Older, less efficacious, and riskier products remain on the market, however. 

Food products contain thousands of compounds — some of nutritive value — nonnutritive components, numerous additives, substances formed during processing, and pesticide residues. Their safety is of utmost importance for human health protection, including cancer risk assessment. In order to evaluate the carcinogenicity of individual food constituents and their mixtures, often of unknown chemical structure, as well as the impact of cooking procedures, short-term reliable and inexpensive tests are necessary. Since cancer risk associated with chemical compounds is thought to stem mainly from their ability to induce mutations, mutagenicity... 

There is a correlation between content of carcinogens in various links of biogeochemical food webs and frequency of stomach cancer. The most significant correlation was monitored in agrogenic biogeochemical nitrate province of the Kzyl-Orda administrative region. The multiple increase in the application of different agrochemicals, such as fertilizers, pesticides, and defoliants, induced the development of... 

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