Talking about environmental pollution

Environmental pollution refers to the phenomenon that human beings directly or indirectly discharge substances or energy that exceed their self-purification ability to the environment, thus reducing environmental quality and adversely affecting human survival and development, ecosystems and property. Specifically, it includes water pollution, air pollution, noise pollution and radioactive pollution. Water pollution refers to the phenomenon that the chemical, physical, biological or radioactive pollution characteristics of water bodies have changed due to the intervention of certain substances, thus affecting the effective use of water, endangering human health or destroying the ecological environment, resulting in the deterioration of water quality. Air pollution refers to the phenomenon that the concentration of pollutants in the air reaches a harmful level, which destroys the ecological system and the conditions for the normal survival and development of human beings and causes harm to people and creatures. Noise pollution refers to the phenomenon that the environmental noise generated exceeds the national environmental noise emission standard and interferes with the normal work, study and life of others. Radioactive pollution refers to the appearance of radioactive substances or rays exceeding the national standards on the surface or inside of substances, people, places and environmental media due to human activities. For example, exceeding the national and local pollutant discharge standards, discharging pollutants in excess of categories, quantities and concentrations; Loading and transporting oil or toxic goods without taking measures to prevent spillage, causing the goods to fall into the water and causing water pollution; Illegal discharge of toxic and harmful substances into the atmosphere, causing air pollution accidents, and so on. With the development of science and technology and the improvement of people's living standards, environmental pollution is also increasing, especially in developing countries. Environmental pollution is becoming one of the common topics in the world. Due to people's insufficient expectation of the negative impact of highly developed industries and unfavorable prevention, three global crises have resulted: resource shortage, environmental pollution and ecological destruction. Humans constantly discharge pollutants into the environment. However, due to the diffusion, dilution, redox and biodegradation of atmosphere, water and soil, etc. The concentration and toxicity of pollutants will naturally decrease, which is called environmental self-purification. If the discharged substances exceed the self-purification capacity of the environment, the environmental quality will change adversely, endangering human health and survival, thus leading to environmental pollution. There are many kinds of environmental pollution: according to environmental factors: air pollution, water pollution and soil pollution. According to human activities: industrial environmental pollution, urban environmental pollution, agricultural environmental pollution. According to the nature and sources of environmental pollution: chemical pollution, biological pollution, physical contamination (noise pollution, radioactivity, electromagnetic wave) solid waste pollution, energy pollution. Environmental pollution will cause direct damage and influence to the ecosystem, such as desertification and forest destruction, and will also cause indirect harm to the ecosystem and human society. Sometimes this indirect environmental impact is more harmful than the direct harm caused at that time, and it is more difficult to eliminate. For example, the greenhouse effect, acid rain and ozone layer destruction are all environmental impacts caused by air pollution. This kind of environmental effect from environmental pollution is lagging behind, and it is often difficult to be detected or predicted when pollution occurs. However, once it happens, it means that environmental pollution has developed to a very serious degree. Of course, the most direct and easily felt consequence of environmental pollution is to reduce the environmental quality of human beings and affect their quality of life, physical health and production activities. For example, urban air pollution causes air pollution, and the incidence of people is rising. Water pollution worsens the quality of water environment, and the quality of drinking water sources generally declines, threatening people's health and causing premature birth or malformation of fetus. Serious pollution incidents not only bring health problems, but also cause social problems. With the intensification of pollution and the improvement of people's awareness of environmental protection, disputes and conflicts between people caused by pollution have increased year by year. Due to people's insufficient expectation of the negative impact of highly developed industries and unfavorable prevention, three global crises have resulted: resource shortage, environmental pollution and ecological destruction. Humans constantly discharge pollutants into the environment. However, due to the diffusion, dilution, redox and biodegradation of atmosphere, water and soil, etc. The concentration and toxicity of pollutants will naturally decrease, which is called environmental self-purification. If the discharged substances exceed the self-purification capacity of the environment, the environmental quality will change adversely, endangering human health and survival, thus leading to environmental pollution. White pollution is a unique environmental pollution in China. A large number of discarded plastic products can be seen everywhere in various public places. They come from nature and are made by human beings, but when they finally belong to nature, they are not easily absorbed by nature, thus affecting the ecological environment of nature. From the perspective of saving resources, plastic products should be recycled as much as possible, because the main source is exhausted oil resources, but the production cost of recycling at this stage is much higher than the direct production cost, which is difficult to do under the current market economy conditions. Facing the increasingly serious problem of white pollution, people hope to find a plastic substitute, which can replace the existing plastic properties without causing white pollution. Degradable plastics came into being. The characteristic of this new functional plastic is that after reaching a certain service life, its chemical structure will degrade obviously under certain environmental conditions, which is harmless or less harmful to the natural environment. For example, starch-filled plastics, first of all, the starch contained in it is rapidly decomposed by amylase secreted by microorganisms in the soil in a short time, which leads to the decline of the mechanical properties of the film. At the same time, the self-oxidant added in the formula reacts with the metal salt in the soil to generate peroxide, which breaks the chain of polyethylene and degrades it into small pieces that are easily swallowed by microorganisms, which are absorbed by the natural environment and play a role in improving the soil. Garbage pollution The phenomenon that garbage encroaches on land, blocks rivers and lakes, interferes with sanitation, affects landscapes and harms crop growth and human health is called garbage pollution. Garbage includes industrial waste residue and domestic garbage. Industrial waste residue refers to the waste produced in the process of industrial production and processing, mainly including coal grindstone, fly ash, steel slag, blast furnace slag, red mud, plastic and petroleum waste residue. Domestic waste is mainly kitchen waste, waste plastics, waste paper, broken glass, metal products, etc. In cities, due to the increasing population, domestic garbage is increasing at the rate of 10% every year, which constitutes a major public hazard. The serious harm of garbage, first of all, occupies a lot of land. The second is to pollute farmland. The third is to pollute groundwater. The fourth is to pollute the atmosphere. Some organic substances in industrial waste residue can produce stench through biodegradation at a certain temperature, thus polluting the atmosphere. The fifth is to spread diseases. Domestic garbage contains germs and parasites. If it is directly used as farmland fertilizer, people may get infectious diseases if they eat vegetables and fruits that have used this fertilizer. With the development of economy and the improvement of people's living standards, urban garbage has increased greatly. Garbage disposal has become an urgent problem in the comprehensive improvement of urban environment. Food contamination of food is one of the three major factors that constitute human life and health. Once food is polluted, it will endanger human health. Food pollution refers to all kinds of foods that people eat, such as grains, fruits, vegetables, fish, meat, eggs and so on. In the process of production, transportation, packaging, storage, sale and cooking, harmful toxic substances or germs are mixed. Food pollution can be divided into biological pollution and chemical pollution. Biological pollution refers to harmful viruses, bacteria, fungi and parasites polluting food. Bacteria and fungi belonging to microorganisms are invisible to the naked eye. Eggs stink and vegetables rot, mainly caused by bacteria and fungi. There are many kinds of bacteria. Some bacteria, such as Proteus, Flavobacterium, Enterobacter, etc., can directly pollute animal food, and can also pollute animal food through tools, containers, washing water, etc., and make food deteriorate. There are many kinds of fungi, more than 50 thousand species. The earliest mold that served mankind was a fungus. Nowadays, people can't eat fermented bean curd and sauce products without mold. But 100 strains can produce toxins, and aflatoxin is the most toxic. Food contaminated with this toxin can cause primary liver cancer in animals. According to the survey, the incidence of liver cancer is several times higher in areas with high aflatoxin in food than in other areas. British scientists believe that breast cancer may be related to aflatoxin. The climate in East China and Central South China is warm and humid, and aflatoxin pollution is widespread, mainly in peanuts and corn, followed by food such as rice. Parasites that pollute food mainly include ascaris lumbricoides, tapeworms and Trichinella spiralis. These parasites generally pollute water and soil through the feces of patients and sick animals, and then pollute fish, fruits and vegetables, which will cause parasitic diseases after people eat them. Chemical pollution is caused by harmful and toxic chemicals that pollute food. Various pesticides are the main sources of chemical pollution of food, as well as industrial wastewater, waste gas and waste residue containing harmful substances such as lead, cadmium, chromium, mercury and nitro compounds. Food additives, such as food pigments, preservatives, chromophores, sweeteners, curing agents and antioxidants; Plastic, paper and metal containers for food packaging. If food is packaged with waste newspapers and old magazines, PCBs contained in these papers will enter the human body through food, which will cause diseases. Polychlorinated biphenyls (PCBs) are the general name of more than 200 chlorinated aromatic hydrocarbons, which are produced and used in large quantities in the world today. It has been proved that traces of PCBs have been found in rivers, seawater, aquatic organisms, soil, atmosphere, wildlife, human milk and fat, and even penguins in Antarctica and whales in the Arctic Ocean. In the process of food processing, adding some food pigments can keep bright colors. But some synthetic pigments are toxic. To prevent food pollution, we should not only pay attention to food hygiene, but also start from all aspects of production, transportation, processing, storage and sales. Only in this way can the problem be fundamentally solved. Soil pollution is the foundation of human food and clothing. Today, with the high development of science and technology, the land has been destroyed unprecedentedly. Among them, soil pollution is like a soft knife, depriving a large area of fertile soil of its productivity. Soil pollution mainly refers to the phenomenon that some harmful substances in the soil greatly exceed the normal content, and the land can not eliminate the influence of these harmful substances. Serious soil pollution will lead to crop growth decline, even wither and die, and these pollution consequences can be found in time. More soil pollution has no obvious performance, but it reduces the quality of agricultural products, especially through the enrichment of harmful substances by crops, which secretly harms the health of livestock and human beings. We must be highly vigilant. Soil pollution mainly comes from domestic sewage and industrial wastewater, waste gas, waste residue, chemical fertilizer and pesticides. Domestic sewage and human and animal manure contain many nutrients that plants need. Irrigation with sewage or application of manure usually increases crop yield. However, pathogens, viruses, parasites and eggs in these wastewater and wastes enter the farmland and deposit in the soil, causing soil pollution. Human contact with contaminated soil and agricultural products can cause tetanus, epidemics, endemic diseases and parasitic diseases. Modern agriculture uses a large number of chemical fertilizers, resulting in a large number of inorganic substances such as nitrate, sulfate and chloride remaining in the soil. They destroy the physical and chemical properties of soil, make the soil hard and salinized, thus reducing crop yield. The use of pesticides will make polycyclic aromatic hydrocarbons, polychlorinated biphenyls and other organic substances settle in the soil, poisoning animals, plants and people. Harmful substances such as smoke, sulfur dioxide, nitrogen oxides and radioactive dust in the atmosphere will naturally settle in the soil or with rain and snow. Harmful substances such as cadmium and lead in the exhaust gas from smelters and automobiles will also be adsorbed by the soil, causing pollution. Therefore, the soil around the factory and on both sides of the road is the most vulnerable to pollution. Heavy metal pollution is the most harmful in soil pollution. Chromium, manganese and nickel can also cause cancer in different parts of the human body. Excessive metal content in soil can also harm plants. According to experiments, when the soil contains 20 mg of copper per kilogram, wheat will die, and when it reaches 250 mg, rice will die. More than 50 milligrams of zinc per kilogram of soil will affect the growth of crops. Once the soil is polluted, its influence is difficult to eliminate. Organic pesticides decompose very slowly, and heavy metals do not decompose at all. Even if the polluted land is no longer polluted, it will still contain high levels of harmful substances after three to five years, which can be enriched through the food chain and endanger human beings. Therefore, the plants on the heavily polluted land can not only be eaten, but also can not be used as feed or fertilizer.