What is the progress of China's pesticide and veterinary drug residue standards for agricultural products and food?
In order to ascertain the progress of the formulation and revision of China's pesticide and veterinary drug standards and the principles and scientific nature of pesticide and veterinary drug residue standard setting, a reporter conducted exclusive interviews with Researcher Gu Baogen, a member of the Agricultural Product Quality and Safety Expert Group of the Ministry of Agriculture, Researcher Jian Qiu of the Institute for the Control of Agrochemicals of the Ministry of Agriculture, and Researcher Zhang Cunshuai of the China Institute of Veterinary Drug Control. The three experts gave clear responses and interpretations on this issue.
Reporter: What are pesticide and veterinary drug residues? Do residues necessarily affect human health?
Expert: Pesticide residues refer to the parent pesticide, metabolites, reaction products and impurities, etc. that remain in agricultural products after pesticides are used on crops; while veterinary drug residues refer to the original drug form, metabolites and impurities, etc. that accumulate or remain in the tissues and organs of food-producing animals after veterinary drugs are used, or that enter the milk of lactating animals or the eggs of laying poultry. Just as we humans need injections and medicine when we are sick, animals need veterinary drugs for treatment when they are sick, and crops need pesticides for prevention and control when they suffer from pests and diseases. No matter which country, agricultural production requires the use of pesticides and veterinary drugs. Generally speaking, countries with a high degree of agricultural modernization use larger quantities of pesticides and veterinary drugs. According to 2000 statistics from the United Nations Food and Agriculture Organization, pesticide use in developed countries was 1.5-2.5 times that of developing countries. Therefore, agricultural products produced by all countries will contain pesticide or veterinary drug residues.
Agricultural products containing pesticide and veterinary drug residues are not necessarily unsafe. Whether they affect human health depends on whether the residue level exceeds the standard. Only when the residue level exceeds the standard will it affect the health of consumers; agricultural products that do not exceed the standard will not affect health.
Reporter: How are pesticide and veterinary drug residue safety standards formulated?
⟦NL> Expert: Internationally, unified methods and procedures have been established for setting pesticide and veterinary drug residue standards (that is, maximum residue limits for pesticides (veterinary drugs), MRLs). China also adopts international standards and methods, and is the same as the Codex Alimentarius Commission (CAC) and developed countries such as Europe, the United States and Japan in terms of standard-setting technology, rules and procedures.
Pesticide and veterinary drug residue standards are calculated using risk assessment techniques based on the toxicity of the drug, the residue level of the drug in agricultural products, and our food consumption structure. Generally, at least four steps are required. First, the toxicity of pesticides and veterinary drugs is determined through mammalian tests, and the acceptable daily intake is determined, that is, the amount of a certain pesticide or veterinary drug that a person can ingest daily from food or drinking water over a lifetime without obvious harm to health. Second, standardized residue trial studies are used to determine the metabolism and degradation process of pesticides in plants and veterinary drugs in animals, so as to clarify the main metabolites and distribution of pesticides and veterinary drugs in crops or animals, and then determine their residue levels. Third, based on the amount and structure of Chinese dietary consumption, determine the amount of various agricultural products each person needs to consume per day and their proportion in all food. Fourth, determine the maximum residue limit value through risk assessment calculation.
It should be pointed out that when formulating residue standards, the basis is the greatest possible safety risk, that is, calculation is based on a person eating a certain agricultural product every day for a lifetime and the maximum amount that may be eaten; on this basis, taking into account differences among species and the safety of pregnant women and children, a 100-fold safety factor is added in the calculation. That is to say, the standard value is usually one percent of the risk assessment safety value, so the standard is very strict and has a large margin of safety. Therefore, it is not frightening for food to contain pesticide and veterinary drug residues; as long as the residue level is below the standard, it is safe.
According to international practice, the formulation of residue standards must follow the principles of scientific technology, fair rules and transparent process. In terms of rules, the principle is fair trade. In accordance with the transparency requirements of the World Trade Organization (WTO) Agreement on Technical Barriers to Trade (TBT Agreement) and the Agreement on the Application of Sanitary and Phytosanitary Measures (SPS Agreement), intended pesticide and veterinary drug residue standards must be notified to WTO members or organizations, and members must accept review of the scientific nature and fairness of the standards. The pesticide and veterinary drug residue standards formulated by China have all undergone official review by governments of various countries. In terms of procedure, the principle is openness and transparency. In accordance with the openness and transparency requirements of the Food Safety Law, the entire process of pesticide residue standard formulation is made public to society. During the drafting stage, opinions from the domestic public and relevant industry departments must be widely solicited on the official website. After review and approval by the National Pesticide Residue Standard Review Committee, it accepts review by WTO member states, and after approval it is jointly promulgated and implemented by the National Health and Family Planning Commission and the Ministry of Agriculture.
Reporter: How many pesticide and veterinary drug residue standards does China have?
Expert: Pesticide and veterinary drug residue standards are the safety valve for agricultural products. Before the Food Safety Law was promulgated in 2009, China's pesticide and veterinary drug residue standards had problems such as a small number of standards, lagging standard formulation, and relatively low technical level. After the Food Safety Law was promulgated, China accelerated the pace of building a national pesticide and veterinary drug residue standard system. Through more than five years of effort, China has formulated a pesticide and veterinary drug reference standard system covering all important agricultural products, providing a guarantee for ensuring the quality and safety of agricultural products.
In 2014, the Ministry of Agriculture and the National Health and Family Planning Commission jointly issued the national food safety standard Maximum Residue Limits for Pesticides in Food (GB2763-2014), which stipulated 3650 limit indicators for 387 pesticides in 284 types (categories) of food. The residue limits stipulated by this standard cover 12 major categories of crops or products, including vegetables, fruits, grains, oilseeds and oils, sugar crops, beverages, condiments, nuts, edible fungi, mammalian meat, eggs, poultry offal and meat. In addition to conventional grains, vegetables and fruits, it includes pesticide residue limit indicators for primary processed products such as fruit juice, preserved fruit and dried fruit. China has made prohibition and restriction provisions for 135 veterinary drugs, among which 94 veterinary drugs have veterinary drug residue limit provisions, involving 1548 limit values, 9 veterinary drugs are allowed for use but must not be detected, and 32 veterinary drugs are prohibited for use; 519 veterinary drug residue detection method standards have been established.
Due to historical reasons, the number of China's pesticide and veterinary drug residue standards is still fewer than that of developed countries in Europe and the United States, but many residue standards in Europe and the United States are not formulated solely for food safety. A large number of standards formulated for agricultural products not produced in their regions and countries mainly serve trade barriers. At present, China is the country that formulates standards fastest, and it mainly formulates them based on food safety needs. The existing pesticide and veterinary drug residue standards basically cover the types of plant-based and animal-based foods that people commonly consume, providing a guarantee for China's food safety.