Garbage pollution
The phenomenon that garbage encroaches on land, blocks rivers and lakes, hinders health, affects landscape, 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 pollution
Food is one of the three elements 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.