What is pesticide residue? Pesticide residue refers to the trace amount of pesticides remaining in organisms, agricultural products (or food) and the environment after pesticide use, in addition to the pesticide itself, but also including the toxic metabolites and impurities of pesticides, is a general term for pesticides and other related substances. The amount of pesticide residue that remains is called residue and is expressed in how many milligrams (mg/kg) there are in each kilogram of sample. Pesticide residue is an inevitable phenomenon after application, but if it exceeds the maximum residue limit standard, it will have adverse effects on humans and animals or the risk of poisoning organisms in the ecosystem through the food chain.
Do all agricultural products have pesticide residues? Diseases and pests often occur in the process of agricultural production, so it is necessary to use pesticides for control, but some organic agriculture uses natural biopesticides, so almost all agricultural products may contain pesticide residues. Chinese agricultural products are, and so are foreign agricultural products. In fact, the higher the degree of agricultural modernization, the greater the use of pesticides, therefore, the use of pesticides in developed countries is generally higher than that in developing countries, according to the statistics of the Food and Agriculture Organization of the United Nations in 2000, the use of pesticides per unit area in developed countries is 1.5-2.5 times that in developing countries. In the production practice, due to restrictions on the use of pesticide technology, the actual utilization rate of pesticides is only 30%, most of the pesticides are lost to the environment, the pesticide residues on the plant are mainly retained on the surface of the crop, and the pesticide part with internal absorption will be absorbed into the plant body. The pesticides on the plants have been exposed to wind and rain, natural degradation and biodegradation, and the amount of pesticide residues is very small at the time of harvest. However, in order to ensure the safety of agricultural products, pesticide residue standards should be formulated to control the amount of pesticide residues in agricultural products in a safe range. No residue is idealistic, no country can do it, but reducing pesticide residues and ensuring the safety of agricultural products is the goal of agriculture and pesticide management in all countries.
Is pesticides necessary? In recent years, agricultural product quality safety incidents have occurred from time to time, and some people will have the question of "can not not use pesticides?" In fact, the use of pesticides in the world is more than 200 years of history, but during this period, the use of pesticides has been increasing, because the population growth needs to vigorously develop agricultural production to ensure the security of food supply; At the same time, the development of modern agriculture is increasingly dependent on the use of pesticides. Some studies have pointed out that the losses caused by crop diseases and pests can reach up to 70%, and about 40% of the losses can be recovered through the correct use of pesticides. China is a country with a large population of arable land, grain increase and farmers' income has always been the main goal of agricultural production, and the use of pesticides to control diseases, pests and grasses to reduce crop production is a necessary technical measure, if you do not use pesticides, our country will certainly appear famine! Modern agricultural technologies such as agricultural mechanization require the use of pesticides for weeding, height control, leaf removal, fruit setting and other measures to facilitate mechanized operation. Pesticides are as important and essential to plants as medicine is to humans. However, some measures can also be taken to reduce pesticide residues. First, comprehensive disease and pest control can be carried out to reduce the amount of pesticides. The second is to correctly regulate the use of pesticides and reduce the amount of pesticide residues; The third is to vigorously promote biopesticides, reduce the use of chemical pesticides, and constantly reduce the level of pesticide residues. The agricultural sector has been working on these efforts.
Can agricultural products containing pesticide residues be eaten? Whether it is safe to eat agricultural products containing pesticide residues depends on the amount of pesticide residue, toxicity, and the amount consumed. In order to ensure the safety of agricultural products, countries develop pesticide residue limit standards based on toxicological data of pesticides (mainly daily allowable intake and acute reference dose) and food structure of residents, etc., the residual amount is safe and can be safely consumed, while excessive agricultural products have safety risks and should not be eaten. It should be added that the safety factor of at least 100 times is increased in the formulation of the residue standard, so the residue standard has a large insurance factor, in theory, even if the accidental consumption of agricultural products with excessive residues may not occur.
In order to ensure the safety of agricultural products, China carries out strict management of pesticide safety, pesticide registration needs to carry out 18 acute, sub-chronic and chronic safety tests in two years, and will not approve the registration of products with carcinogenic teratogenic safety hazards. China has also adopted the most stringent management of highly toxic pesticides, and has banned the elimination of 33 highly toxic pesticides, including methamidophos and other products that are still widely used in some developed countries such as the United States, while vigorously developing biopesticides. At present, the proportion of highly toxic pesticides in China has been reduced from 30% to less than 2%, and more than 72% of pesticides are low-toxic products, pesticide safety has been greatly improved, the occurrence of poisoning in rural production has been reduced, and the death rate of suicide by drinking drugs has also decreased significantly. This is not to say that our agricultural products are absolutely safe, to be sure, pesticides are safer today than they used to be. If you are concerned about pesticide residues, you can also take measures such as blistering and peeling when eating fresh vegetables and fruits to remove possible residues.
Which agricultural products have greater residual risk? General organic agricultural products, green food and pollution-free agricultural products, because of the strict regulations on the pesticides used and the use of methods, pesticide residues are relatively small, less than the standard, relatively safe. Wheat, rice and
Corn and other food crops, due to the long growth period and long storage period, most of the pesticide residues will be degraded, and after processing and cooking, the residues will be further removed and degraded, relatively safe. Vegetables and fruits because most of them are fresh food, pesticide residue degradation is less, so the state on the use of vegetables and fruits of pesticide management is more strict, in addition to the prohibition of the use of highly toxic pesticides, pesticides allowed to strictly regulate the use of technology and safety interval, normal production will not appear safety problems. For some continuously harvested fresh vegetables and fruits, the residual risk may be relatively greater. Agricultural products have pesticide residues, due to the strict management of pesticides and residues in various countries, agricultural products that meet the pesticide residue standards are safe, therefore, the residue and safety of agricultural products should be correctly understood. To enhance safety awareness, but don't talk about drug color change. The amount of pesticide residue is very small, and its harm is far less than some environmental and air pollutants and pathogenic microorganisms.
How to determine the standard of pesticide residues? Pesticide residue standards include pesticide residue limit standards (that is, maximum residue limits), pesticide residue detection method standards, etc. The most directly related to consumers is the pesticide residue limit standards in food or edible agricultural products. China, like developed countries such as Europe, the United States, Japan and Australia, adopts internationally common risk assessment techniques and methods, and formulates national standards for pesticide residue limits in order to consider the maximum possible risk. The specific methods and steps are as follows: First, according to the production, processing, circulation, consumption, import and export needs of agricultural products and the actual situation of pesticide use, determine the agricultural products (or food) and pesticide combination that need to establish the residue limit standard; Then the simulation dynamic test of pesticide residue degradation, national dietary structure investigation and pesticide toxicology research were carried out. The residual value of pesticides remaining in agricultural products (or food) under normal use (including the median value, the maximum residual value, etc.), the dietary data of Chinese consumers (the daily consumption amount of each edible agricultural product or food in different regions, different ages, and different genders) and the toxicity of pesticides (including the daily allowable intake, acute reference dose, etc.), are obtained respectively. On this basis, the risk assessment of dietary intake of pesticide residues was carried out, and the recommended value of pesticide residue limit was obtained. Finally, after deliberation and approval by the food safety pesticide residue national standard Review Committee, it is jointly promulgated by the Ministry of Health and the Ministry of Agriculture.
In particular, the formulation of residue standards is based on the maximum possible risk, that is, the implementation of the most stringent safety requirements; On this basis, it is necessary to increase the safety factor by at least 100 times, for example, if the amount of a pesticide residue in the food is 50mg/kg, there may be a safety risk, then the standard is set at 0.5mg/kg.
Is China's pesticide residue standard lower than that of Europe and the United States? People often like to compare our standards with those of developed countries in Europe and America. In terms of the number of pesticide residue standards, due to the long history of pesticide management in Europe and the United States, the number of residues is more than that in China. However, in terms of the level of standards, it is difficult to compare the level of residual standards in different countries. From the technical level, the agricultural production, pesticide use and food structure of different countries are different, so there will be certain differences in residue standards. From the management level, although the main purpose of the development of residue standards is to ensure food safety, countries are now increasingly using pesticide residues as technical barriers to international trade in agricultural products and, if necessary, as political chips.
The differences of pesticide residue standards in different countries are also affected by the following factors. First, for pesticides that are not produced or used in the country, the most stringent standards are often formulated, and for pesticides used in the country, especially those used in export agricultural products, the residue standards are as loose as possible within the safe range. For example, the United States, the European Union and Japan implement the standard limit for pesticides that are not registered in their own countries (that is, 0.01~0.05mg/kg), and this concentration is difficult to detect by instruments in many developing countries; However, for pesticides registered for use in the country, even if the pesticide is highly toxic, its standards are loose. For example, the United States stipulates that the standard of highly toxic pesticide methamphetamine on
Celery is 1mg/kg, and that on
Cauliflower is 0.5mg/kg, and Japan stipulates that celery is 5mg/kg and cauliflower is 1mg/kg. The second is strict standards on crops that the country does not have or mainly relies on imports. Such as chlorobenzoamide is a new insecticide, the European Union standard on grapes is 1mg/kg, and in rice and other grains is 0.01mg/kg, tea is 0.02mg/kg, grapes can be eaten, the standard should be higher, but grapes are the dominant crops in Europe, so the standard is loose; For example, the commonly used fungicide chlorotronil, the EU standard for direct consumption of apples and pears is 1mg/kg, while it is 0.01mg/kg on rice and other grains, and 0.1mg/kg on tea. Third, the same crop, national standards are different, such as safety is not very high fungicide in rice residue standards, Japan is 5mg/kg, the EU is 0.02mg/kg, a difference of 100 times; Another example is the highly toxic pesticide methyl parathion, which is 1mg/kg in Japan and 0.02mg/kg in the EU, a difference of 50 times.
In order to coordinate and unify residue standards, the Codex Alimentarius Commission is responsible for developing international standards for pesticide residues, but even if there are international residue standards, most developed countries implement their own national standards, while most developing countries often can only implement international standards because of their weak ability to develop residue standards. China is the chair of the Codex Alimentarius pesticide residue Standards Committee, therefore, China's pesticide residue standards as far as possible with the international Codex Alimentarius standards (rather than European, American and Japanese standards), some standards are lower than developed countries, but some standards are higher than developed countries. Such as the new pesticide methoxyfenazide in China's standard in
Cabbage is 2mg/kg, while the United States and Japan's is 7mg/kg; Malathion is an old pesticide, China's standard in citrus, apples, beans is 2mg/kg, in brown rice is 1mg/kg, in
Radish is 0.5mg/kg, are stricter than the United States standard of 8mg/kg; The standard of azinoxone in soybeans is 0.05mg/kg, while the standard of the United States is 0.3mg/kg, and the standard of the European Union and Japan is 0.1mg/kg. The standard of commonly used fungicide thiamendazole in mushrooms in China is 5mg/kg, the United States is 40mg/kg, the European Union is 10mg/kg, and Japan is 60mg/kg, which are 8, 2, and 12 times stricter than them, respectively. The formulation of pesticide residue standards in China mainly considers safety, and rarely involves trade protection. It can be seen that no matter whether there are differences in the level of residue standards in different countries, the residue standards are formulated according to the safety risk assessment. As long as the residue standards are met, agricultural products are safe, and the standards of other countries cannot be used to judge whether there is safety, and the standards of one country cannot be used to deny the standards of other countries, which is not scientific. Because the pesticide residue standard is not only based on the safety risk assessment results to develop, but also comprehensive consideration of industrial development, international trade and other factors.
What is the current situation of pesticide residues in agricultural products in China? The current situation of pesticide residues in agricultural products in China can be summarized in three sentences, that is, it has been improving in recent years, and the overall situation is better, but there are still hidden dangers. To be specific, first, the national 3-5 times a year of agricultural product quality and safety routine monitoring shows that the results are improved year by year and greatly improved, not only reflected in the continuous decline of pesticide residues over the standard rate, from more than 50% ten years ago to less than 10% at present; Ten years ago, the number of vegetables with more than 1 mg/kg of pesticide residues was higher, but it is now rare, and only occasionally more than 1 mg/kg of pesticides were detected. Second, the current qualified rate of pesticide residue monitoring of agricultural products is generally high, such as rice and fruit as high as more than 98%, vegetables and tea are also more than 95%. Third, the current situation of pesticide residues is not stable, and there are still some risks and hidden dangers, such as the heavy occurrence of diseases and pests and the large use of pesticides in the summer in southern regions or other regions, which is easy to cause excessive pesticide residues in agricultural products, and for example, in the case of off-season cultivation in facilities, due to the large amount of pesticides and not easy to degrade, it is also easy to cause excessive pesticide residues. With the improvement of residue limit standards at home and abroad or the increase of monitoring pesticide types, agricultural products that did not exceed the standard have become excessive; In particular, due to the small scale of China's agricultural production industry, there are many thousands of farmers dispersed production and management, coupled with relatively backward production technology, base approval and market access is difficult to truly achieve, resulting in more difficult supervision. At the same time, the number of pesticide residue standards in China is relatively small compared with developed countries, so it is very important to speed up the formulation and improvement of pesticide residue standards.
How to remove pesticide residues? Pesticide residues in produce can be removed or reduced by a number of methods, often simple methods including placing, washing, cooking, and peeling. First, because pesticide residues will continue to degrade over time, some storable potatoes, cabbage, cucumbers, tomatoes, etc., can be placed for a few days after purchase, on the one hand, agricultural products can continue to mature, on the other hand, pesticide degradation residues will be reduced. The second is washing, pesticide residues remaining on the surface or outside of agricultural products are also easier to be washed off by water or dishwashing liquid, therefore, before cooking the vegetables with water for half an hour, and then appropriate to add detergent rinse, basically can remove the surface of pesticide residues. Third, cooking, high temperatures can generally make pesticide residues degrade faster. Fourth, peel, apple, pear, citrus and other agricultural products on the skin of pesticide residues are generally higher than the internal tissue, therefore, peeling, peeling is a good method.
However, it should be noted that no matter what method is adopted, it is difficult to completely remove pesticide residues in agricultural products, especially small amounts of pesticide residues that have entered the internal tissues of agricultural products. And if other substances are used in the process of removing pesticide residues, such as dishwashing liquid, bacterial agent, enzyme agent, etc., it is also necessary to consider the safety of the residues of these substances after use on the human body, because dishwashing liquid can remove pesticide residues, but its own as a chemical or biological pollutant may also cause secondary pollution to agricultural products (or food).
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Source from:
(www.gov.cn) 
