Pesticide is a special chemical, which can not only control agricultural and forestry diseases and insect pests, but also do harm to people and animals. Therefore, the use of pesticides, on the one hand, benefits mankind, on the other hand, it also brings harm to the environment on which human beings depend. According to literature reports, the utilization rate of pesticides is generally 10%, and about 90% remains in the environment, causing environmental pollution. A large number of lost pesticides volatilize into the air, flow into the water body, settle and gather in the soil, pollute agricultural animals, fish, fruits and other products, and transfer to the human body through food chain enrichment, which is harmful to the human body. Pesticides can indirectly cause harm to human body. The indirect way is that pesticides pollute the environment, gradually enrich the food chain and finally enter the human body, causing chronic poisoning. Highly effective and highly toxic pesticides are highly toxic and remain in the environment for a long time. When people and animals eat food containing pesticide residues, it will cause cumulative poisoning. This kind of harm often takes a long time to show symptoms and is not recognized by people; It eventually enters the human body through the enrichment of the food chain, so it is not easy to be found in time. So it is generally ignored. Moreover, this kind of pollution has a wide range and harms many people. Many times, human beings are poisoning themselves. So this kind of harm is more dangerous. A large number of pesticides will kill other beneficial birds and animals that eat pests while killing pests, so that the beneficial birds and animals that eat pests are greatly reduced, thus destroying the ecological balance. In addition, the frequent use of pesticides makes pests resistant to drugs, which leads to the increase of drug use times and doses, environmental pollution and ecological destruction, thus forming a vicious circle of pesticide abuse. Pesticides that enter the water body with drainage or rainwater poison the reproduction and growth of aquatic organisms, destroy the water quality of freshwater fishery waters and offshore waters, affect the development of fish eggs and embryos, make the hatched fry grow slowly or die, accumulate in adult fish, make them inedible, and lead to the decline of reproduction. With the increasing consumption, fishery water quality is deteriorating, fishery pollution accidents occur from time to time, and fishery production is seriously threatened, which often leads to a significant reduction in fishery output and direct economic losses. The toxicity of compounds is an inherent characteristic that can cause harm to people (or animals), and the harm of compounds is a function of their toxicity, that is, exposure to compounds under specific environmental conditions is a condition that may cause harm to people.
Weaken the productivity of crops. Crops are like people. Eating too much is not only bad for growth, but also bad for health. There are two main consequences of excessive fertilization on crops: first, it is easy to lodging, and once lodging occurs, it will inevitably lead to reduced grain production; The other is prone to pests and diseases. Excessive application of nitrogen fertilizer will weaken the ability of crops to resist pests and diseases, make them vulnerable to pests and diseases, and then increase the amount of pesticides to eliminate pests and diseases, which directly threatens food safety.
Hazard 2: aggravate environmental pollution. When the excess fertilizer exceeds the soil's retention capacity, it will flow into the surrounding water bodies, causing agricultural non-point source pollution, eutrophication of water bodies, algae breeding and then destroying the water environment. According to statistics, unreasonable fertilization leads to more than 10 million tons of nitrogen flowing out of farmland every year in China, resulting in direct economic losses of about 30 billion yuan. Excessive fertilizer will also penetrate into shallow groundwater within 20 meters, which will increase the nitrate content in groundwater.
The third hazard: wasting a lot of scarce resources. If we can save the wasted fertilizer, it will alleviate the energy shortage in China. In 2004 alone, fertilizer production in China consumed about 654.38 billion tons of standard coal, exceeding 5% of the national energy consumption. In addition, China's fertilizer production consumes more than 654.38 billion tons of high-grade phosphate rock every year, and phosphate rock has been listed in the list of scarce resources after 2065.438+00 by the Ministry of Land and Resources. Fertilizer production also consumes 72% of sulfur resources in China.