Остатки пестицидов в продуктах питания: источники, регулирование и риски.

Pesticide residue refers to the pesticides that may remain on or in food, after they are applied to food crops. The maximum allowable levels of these residues in foods are stipulated by regulatory bodies in many countries. Regulations such as pre harvest intervals also prevent harvest of crop or livestock products if recently treated in order to allow residue concentrations to decrease over time to safe levels before harvest.

A pesticide is a substance or a mixture of substances used for killing pests: organisms dangerous to cultivated plants or to animals. The term applies to various pesticides such as insecticide, fungicide, herbicide and nematocide. The definition of residue of pesticide according to the world health organisation (WHO) is: Any specified substances in or on food, agricultural commodities or animal feed resulting from the use of a pesticide. The term includes any derivatives of a pesticide, such as conversion products, metabolites, reaction products and impurities considered to be of toxicological significance. The term “pesticide residue” includes residues from unknown or unavoidable sources (e. g. environmental) as well as known uses of the chemical. The definition of a residue for compliance with maximum residue limits (MRLs) is that combination of the pesticide and its metabolites, derivatives and related compounds to which the MRL applies.

Prior to 1940, pesticides consisted of inorganic compounds (copper, arsenic, mercury, and lead) and plant derived products. Most of these were abandoned because they were highly toxic and ineffective. Since World War II pesticides composed of synthetic organic compounds were the most important form of pest control. The growth in these pesticides accelerated in late 1940s after Paul Müller discovered DDT in 1939. The effects of pesticides such as aldrin, dieldrin, endrin, chlordane, parathion, captan and 2,4 D were also found at this time. Those pesticides were widely used due to their effective pest control. Problems with environmental issues of DDT became increasingly apparent, since it is persistent and bioaccumulates in the body and the food chain. DDT was banned for agricultural use in 1972 and the others in 2001. Persistent pesticides are no longer used for agriculture, and will not be approved by the authorities. Because the half life in soil is long (for DDT 2–15 years) residues can still be detected in humans at levels 5 to 10 times lower than found in the 1970s.

Each country adopts their own agricultural policies and Maximum Residue Limits (MRL) and Acceptable Daily Intake (ADI). The level of food additive usage varies by country because forms of agriculture are different in regions according to their geographical or climatical factors. Pre harvest intervals are also set to require a crop or livestock product not be harvested before a certain period after application in order to allow the pesticide residue to decrease below maximum residue limits or other tolerance levels. Likewise, restricted entry intervals are the amount of time to allow residue concentrations to decrease before a worker can reenter without protective equipment an area where pesticides have been applied.

Some countries use the International Maximum Residue Limits Codex Alimentarius to define the residue limits; this was established by Food and Agriculture Organization of the United Nations (FAO) and World Health Organization (WHO) in 1963 to develop international food standards, guidelines codes of practices, and recommendation for food safety. Currently the CODEX has 185 Member Countries and 1 member organization (EU). The following is the list of maximum residue limits (MRLs) for spices adopted by the commission. Pesticide Group or sub group of spices MRL (mg/kg) Acephate Entire Group 028 0.2 Azinphos methyl Entire Group 028 0.5 Chlorpyrifos SeedsFruits or berriesRoots or rhizomes 511 Chlorpyrifos methyl SeedsFruits or berriesRoots or rhizomes 10.35 Cypermethrin Fruits or berriesRoots or rhizomes 0.10.2 Diazinon SeedsFruitsRoots or rhizomes 50.10.5 Dichlorvos Entire Group 028 0.1 Dicofol SeedsFruits or berriesRoots or rhizomes 0.050.10.1 Dimethoate SeedsFruits or berriesRoots or rhizomes 50.50.1 Disulfoton Entire Group 028 0.05 Endosulfan SeedsFruits or berriesRoots or rhizomes 150.5 Ethion SeedsFruits or berriesRoots or rhizomes 350.3 Fenitrothion SeedsFruits or berriesRoots or rhizomes 710.1 Iprodione SeedsFruits or berriesRoots or rhizomes 710.1 Malathion SeedsFruits or berriesRoots or rhizomes 210.5 Metalaxyl Seeds 5 Methamidophos Entire Group 028 0.1 Parathion SeedsFruits or berriesRoots or rhizomes 0.10.20.2 Parathion methyl SeedsFruits or berriesRoots or rhizomes 550.3 Permethrin Entire Group 028 0.05 Phenthoate Seeds 7 Phorate SeedsFruits or berriesRoots or rhizomes 0.50.10.1 Phosalone SeedsFruits or berriesRoots or rhizomes 223 Pirimicarb Seeds 5 Pirimiphos methyl Seeds sub groupFruits sub group 30.5 Quintozene Seeds sub group Fruits or berriesRoots or rhizomes 0.10.022 Vinclozolin Entire spice group 0.05

The European Union has a searchable database with the Maximum Residue Limits (MRLs) for 716 pesticides. Under the previous system, revised in 2008, certain pesticide residues were regulated by the commission; others were regulated by Member States, and others were not regulated at all.

Food Standards Australia New Zealand develops the standards for levels of pesticide residues in foods through a consultation process. The New Zealand Food Safety Authority publishes the maximum limits of pesticide residues for foods produced in New Zealand.

Monitoring of pesticide residues in the UK began in the 1950s. From 1977 to 2000 the work was carried out by the Working Party on Pesticide Residues (WPPR), until in 2000 the work was taken over by the Pesticide Residue Committee (PRC). The PRC advise the government through the Pesticides Safety Directorate and the Food Standards Agency (FSA).

In the US, tolerances for the amount of pesticide residue that may remain on food are set by the EPA, and measures are taken to keep pesticide residues below the tolerances. The US EPA has a web page for the allowable tolerances. In order to assess the risks associated with pesticides on human health, the EPA analyzed individual pesticide active ingredients as well as the common toxic effect that groups of pesticides have, called the cumulative risk assessment. Limits that the EPA sets on pesticides before approving them includes a determination of how often the pesticide should be used and how it should be used, in order to protect the public and the environment. In the US, the Food and Drug Administration (FDA) and USDA also routinely check food for the actual levels of pesticide residues. In 2016, over 99% of samples of US produce had no pesticide residue or had residue levels well below the EPA tolerance levels for each pesticide.

In Japan, pesticide residues are regulated by the Food Safety Act. Pesticide tolerances are set by the Ministry of Health, Labour and Welfare through the Drug and Food Safety Committee. Unlisted residue amounts are restricted to 0.01ppm.

In China, the Ministry of Health and the Ministry of Agriculture have jointly established mechanisms and working procedures relating to maximum residue limit standards, while updating them continuously, according to the food safety law and regulations issued by the State Council. From GB25193 2010 to GB28260 2011, from Maximum Residue Limits for 12 Pesticides to 85 pesticides, they have improved the standards in response to Chinese national needs.

Accidental or inadvertent poisoning of agricultural workers due to exposure to pesticides is a very serious matter resulting in many deaths and hospitalizations. The effects of pesticides at high concentrations on human health is a thus a matter of much study, resulting in many publications on the toxicology of pesticides. However the maximum residue limits of pesticides in food are low, and are carefully set by the authorities to ensure, to their best judgement, no health impacts. According to the American Cancer Society there is no evidence that pesticide residues increase the risk of people getting cancer. There are many studies on the health differences between consumers of organic foods vs consumers of organically grown foods. When the American Academy of Pediatrics reviewed the literature on organic foods in 2012, they found that "current evidence does not support any meaningful nutritional benefits or deficits from eating organic compared with conventionally grown foods, and there are no well powered human studies that directly demonstrate health benefits or disease protection as a result of consuming an organic diet."

In China, a number of incidents have occurred where state limits were exceeded by large amounts or where the wrong pesticide was used. In August 1994, a serious incident of pesticide poisoning of sweet potato crops occurred in Shandong province, China. Because local farmers were not fully educated in the use of insecticides, they used the highly toxic pesticide named parathion instead of trichlorphon. It resulted in over 300 cases of poisoning and 3 deaths. Also, there was a case where a large number of students were poisoned and 23 of them were hospitalized because of vegetables that contained excessive pesticide residues.

Many pesticides achieve their intended use of killing pests by disrupting the nervous system. Due to similarities in brain biochemistry among many different organisms, there is much speculation that these chemicals can have a negative impact on humans as well. Children are especially vulnerable to exposure to pesticides, especially at critical windows of development. Infants and children consume higher amounts of food relative to their body weight, and have a more permeable blood–brain barrier, all of which can contribute to increased risks from exposure to pesticide residues. However in 2008 the OECD report that the existing guideline represents the best available science for assessing the potential for developmental neurotoxicity in human health risk assessment.