Research on Agricultural Green Supply Chain and Food Safety (2)

2.2 Breeding links

2.2.1 Industrial "Three Wastes" Pollution

With the emission of three wastes, many harmful chemical substances such as mercury, arsenic, lead, chromium, cadmium and other metal toxicants and fluoride and other non-metallic toxicants directly threaten the production environment. At present, among 1200 rivers in China, 850 rivers have been polluted to varying degrees. More than 130 lakes and offshore areas have eutrophication problems to varying degrees, and there are 51 lakes under eutrophication. According to estimates, China's heavy metal-contaminated farmland has reached 300 million mu, 136 million mu of farmland has been contaminated with pesticides, polluted land has reached 32.5 million mu for sewage irrigation, 80,000 mu for atmospheric pollution, and 2 million mu for solid waste. The sampling monitoring of 300,000 hectares of basic farmland protection areas in 2002 showed that the rate of heavy metal exceeding the standard was as high as 12.1%.

2.2.2 White pollution

White waste plastic packaging products (bags, films, agricultural films, food containers, beverage bottles, packaging fillers, etc.) that are abandoned in the natural environment during the agricultural production process may also cause pollution and affect the growth of crops. After the plastic film used in farmland ages, it will be broken up and left in the field, will not decompose and rot, destroy the soil structure, hinder the plants from absorbing water and root growth, and affect crop yield. According to the survey, if there is a residual film of 3.9 kg per acre, corn production can be reduced by 11% to 23%, wheat production can be reduced by 9% to 16%, and this pollution is difficult to eliminate. In addition, waste plastic fragments scattered in rivers, lakes and fields are eaten by animals and aquatic organisms, which can lead to illness and death.

2.2.3 Excessive use of chemical fertilizers

China has less than one-tenth of the world's arable land, but recently the use of nitrogen fertilizers has accounted for nearly 30% of the world's total. Nitrogen fertilizers (pure nitrogen) use more than 25 million tons per year, and the amount per unit area is 3 times the world average. However, the utilization rate is only 30% to 35%. It is estimated that the loss of nitrogen fertilizer in China is as high as 15 million tons per year, and a large amount of nitrogen nutrients that have not been absorbed by crops contaminate the soil environment by means of retention, adsorption, and denitrification. The excessive nitrogen fertilizer input, not only can not be fully absorbed and used by crops, but will be converted into a large accumulation of nitrate nitrogen in the soil, causing excessive nitrate content in vegetables and groundwater pollution. Nitrite poisoning can cause methemoglobinemia and cause death. Moreover, nitrites can further generate nitrosoamines and nitrosoamides and other nitroso compounds, which are all carcinogenic factors. A survey conducted in major provincial capital cities in November 2002 showed that the average nitrate content of cabbage such as pakchoi was greater than 3000mg/kg.

2.2.4 Pesticide Pollution

Pesticides also have problems of excessive application. The annual average dosage of pesticides in China is over 250,000 tons, but the utilization rate is only 30%. The rest is drifted and lost, causing pollution to the soil, water sources, air and agricultural and sideline products, resulting in the death of a large number of natural enemies in the field. Caused environmental pollution, but also destroyed the ecological balance. At present, overuse of pesticides in China is up to 40% in rice production and over 50% in cotton production. Since the 1990s, the average annual number of pesticide poisoning in China is about 90,000 people, including more than 7,300 deaths. At the same time, long-lived pesticides can also cause phytotoxicity on crops that grow afterwards. Nearly one-sixth of the cultivated land in Heilongjiang Province has left a long-term residual effect of herbicides. It has caused serious damage to sensitive crops of post-harvest crops in crop rotations and is called a “cancer field”. The area of ​​crop phytotoxicity in the country is about 3 million mu, with direct economic losses of more than 100 million yuan and indirect losses of more than 1 billion yuan. In addition, the problem of insecticide resistance caused by a single pesticide structure and improper use has become increasingly common and frequent, resulting in a significant decline in control effectiveness. According to statistics, at least 30 kinds of agricultural pests in China have produced varying degrees of resistance to 11 fungicides against 40 insecticides and 10 pathogens.

2.2.5 Residues of veterinary drugs

Veterinary drug residues will have some adverse effects on human health, mainly manifested in allergic reactions and allergic reactions, acute toxic effects, pathogen resistance, "triple (teratogenic, mutagenic and carcinogenic)" effect. In recent years, there have been numerous incidents such as the "lean meat" incident in pork, the "chloramphenicol incident" in aquatic products, and the drugs (chloramphenicol, furans, etc.) in enteral casings in Europe. On the one hand, Chinese consumers' health is affected. The threat, on the other hand, was seriously affected by exports. From 1998 to 2002, there have been 58 cases of poisoning of poultry meat or fish containing lean pork or viscera, or even lean meat, in all parts of the country. There were 1957 poisonings, and the maximum number of poisonings reached 530. people.

2.3 Postpartum processing

2.3.1 Poor processing capacity of agricultural products

Compared with developed countries, the overall level of China's agricultural product processing industry has a large gap. The rate of agricultural products processing and deep processing (more than twice processing) in developed countries is about 80% to 90%, while that in China is only about 20% to 30%; the processed foods in developed countries account for about 80% of the total food consumption. However, China still accounts for less than 30%; the output value of the agricultural product processing industry in developed countries is generally 2 to 3 times that of agricultural output, while in China, it is only about 80%.

2.3.2 Illegal production and proliferation of fake and shoddy foods

At present, many food processing companies in China are not strictly sterilized and sterilized according to technological requirements. They abuse or excessively add chemical materials such as preservatives, pigments, formalin, etc. Some companies even disregard the safety of consumers and illegally produce counterfeit foods for sale. Expired, deteriorating foods, etc., all have hidden dangers for food safety. In 2001, the General Administration of Quality Supervision of the People's Republic of China conducted spot checks on 600,85 rice, pasta, oil, soy sauce, and vinegar basic food production companies, with an average pass rate of only 59.9% to 60%. The pass rate of rice was 81.5%, edible oil 95.2%, vinegar 74.4%, wheat flour 43.6%, and soy sauce 31.6%. In addition, in the "two investigations", there were also 9,169 enterprises without business licenses, accounting for 15.3% of the total; 25% of enterprises did not implement standards or non-standard production.

2.3.3 The number of food safety inspection and inspection institutions and personnel in China is insufficient, and technology and equipment are relatively backward. This has become a "bottleneck" problem that restricts the construction of a food safety system.

(to be continued)