What are the hazards of environmental pollution and health damage?
1, the harm of environmental pollution to human body mainly has three aspects:
(1) Acute hazard: the concentration of pollutants is very high in a short time, or several pollutants can cause acute hazard to human body.
(2) Chronic harm: Chronic harm mainly refers to the harm to human body caused by the continuous action of small doses of pollutants. For example, the impact of air pollution on the incidence of chronic respiratory inflammation.
(3) Long-term harm: The harm of environmental pollution to human body is generally manifested after a long incubation period, such as the carcinogenic effect of environmental factors. Carcinogenic factors in the environment mainly include physical, chemical and biological factors. Physical factors, such as leukemia and lung cancer caused by radiation exposure or inhalation of radioactive substances in vitro, and biological factors, such as tropical malignant lymphoma, have been proved to be the virus primers transmitted by blood-sucking Kun. Chemical factors, according to animal experiments, there are more than 1 100 carcinogens.
2. Harm of harmful chemicals to organisms
Pesticide is a common harmful chemical. When people use pesticides to kill bacteria and pests, it will also cause environmental pollution and harm to many kinds of creatures, including humans.
Many pesticides are compounds that are not easily decomposed. After being absorbed by organisms, it will accumulate in organisms, resulting in the content of such harmful substances in organisms far exceeding the external environment. This phenomenon is called bioaccumulation. Biological enrichment is strengthened with the extension of food chain. For example, DDT, as an efficient pesticide, was widely used to control pests decades ago. DDT was used to control animals in the lake in a certain place in the United States, so that DDT remained in the lake, and the DDT content in zooplankton was more than 1 10,000 times that in the lake. Small fish eat zooplankton and big fish eat small fish, so that the DDT content of these big fish is as high as 8 million times that of lake water.
3. Harm of heavy metals to living things Some heavy metals such as manganese, copper and zinc are essential trace elements for living things, but most heavy metals such as mercury and lead are toxic to living things. Heavy metals such as mercury and lead in the ecological environment can also be bioaccumulated in a large number of organisms, thus causing serious harm.
The influence of 4.4. Effects of mercury on life activities of Daphnia.
It can be seen from demonstration experiments that mercury is toxic to Daphnia. Scientists have found that mercury in nature can be transformed into methyl mercury with more toxicity through the action of microorganisms in water. In the seawater polluted by methylmercury, algae plants change color and a large number of marine fish die. Scientists also found that PbCl2 solution with a mass concentration of only 4 mg/L can obviously inhibit the normal photosynthesis of spinach and tomato ... It can be seen that heavy metals such as mercury and lead are very harmful to the normal life activities of organisms.
5. Eutrophication is harmful to living things. Eutrophication refers to the phenomenon that the water quality deteriorates due to the excessive content of mineral elements necessary for plants such as N and P in the water. Water contains appropriate mineral elements such as nitrogen and phosphorus, which are necessary for the growth and development of algae. But if these mineral elements enter the water body in large quantities, algae and other plankton will multiply in large quantities. After death, these organisms are first decomposed by aerobic microorganisms, which significantly reduces the dissolved oxygen content in water. Then, the biological debris will be decomposed by anaerobic microorganisms, producing toxic substances such as hydrogen sulfide and methane, which will lead to a large number of deaths of aquatic organisms such as fish. Slow-flowing water bodies such as lakes and bays where eutrophication occurs are blue, red and brown due to different types of plankton. Eutrophication in ponds and lakes is called "water bloom" and in seawater is called "red tide". Industrial wastewater, domestic sewage and water discharged from farmland contain many mineral elements necessary for plants, such as N and P, which are discharged into ponds and lakes in large quantities, resulting in eutrophication of ponds and lakes. Eutrophication of ponds and lakes not only affects aquaculture, but also makes water contain carcinogens such as nitrite, which seriously affects the drinking water safety of people and livestock.
Environment and human health
With the environmental pollution becoming more and more serious, many people breathe polluted air, drink polluted water and eat agricultural products grown from polluted soil all day long, and there is noise in their ears. Environmental pollution is a serious threat to human health.
1. Air pollution and human health
Air pollution mainly refers to the chemical pollution of the atmosphere. There are many kinds of chemical pollutants in the atmosphere, and dozens of them are seriously harmful to human body. The air pollution in China belongs to coal-burning pollution, and the main pollutants are soot and sulfur dioxide, as well as nitrogen oxides and carbon monoxide. These pollutants mainly enter the human body through the respiratory tract, and are directly transported from the blood to the whole body without detoxification of the liver. Therefore, the chemical pollution of the atmosphere is very harmful to human health. This kind of harm can be divided into three types: chronic poisoning, acute poisoning and carcinogenesis.
The concentration of chemical pollutants in the atmosphere of chronic poisoning is generally low, which mainly produces chronic toxic effects on human body. Scientific research shows that chemical pollution in urban air is an important cause of chronic bronchitis, emphysema and bronchial asthma. Acute Poisoning When the factory emits a lot of harmful gases and there is no wind and fog, the chemical pollutants in the atmosphere are not easy to disperse, which will cause acute poisoning. For example, in 196 1 year, three petrochemical enterprises in Niigata, Japan continuously discharged a large number of chemical pollutants such as sulfur dioxide, and windless weather caused asthma among local residents. Later, the local air pollution was controlled and the incidence of asthma decreased.
Carcinogenesis Among the chemical pollutants in the atmosphere, polycyclic aromatic hydrocarbons and lead-containing compounds have carcinogenic effects, among which 3,4-benzopyrene has the strongest effect on lung cancer. The smoke produced by burning coal, cars and cigarettes contains a lot of 3,4-benzopyrene. Chemical pollutants in the atmosphere can also fall into water, soil and crops, and be absorbed and enriched by crops, thus endangering human health.
Air pollution also includes biological pollution and radioactive pollution. Biological pollutants in the atmosphere mainly include pathogenic bacteria, mold spores and pollen. Pathogens can make people suffer from infectious diseases such as tuberculosis, and mold spores and pollen can cause allergic reactions in some people. Radioactive pollutants in the atmosphere mainly come from radioactive wastes from the atomic energy industry and medical X-ray sources, which are easy to cause skin cancer and leukemia.
2. Water pollution and human health
After rivers, lakes and other water bodies are polluted, it will cause serious harm to human health, mainly in the following three aspects. First of all, drinking the organic matter in polluted water and edible sewage will make people poisoned and even die. For example, 1956, there were some patients with unknown etiology in Minamata Bay, Kumamoto Prefecture, Japan. The patient developed symptoms such as spasm, paralysis, dyskinesia, language and hearing disorders, and finally died of pain due to incurable treatment. People call this strange disease Minamata disease. Scientists later discovered that the disease was caused by local industrial wastewater containing mercury. Mercury is converted into methylmercury and enriched in fish, shrimp and shellfish. If people eat these fish, shrimp and shellfish for a long time, methylmercury will cause chronic methylmercury poisoning, mainly brain cell damage. Methylmercury in pregnant women can even make children stunted, mentally retarded and deformed limbs. Second, the water polluted by human and animal feces and domestic garbage can cause infectious diseases such as viral hepatitis and bacillary dysentery, as well as parasitic diseases such as schistosomiasis. Thirdly, some carcinogenic chemicals, such As arsenic (As), chromium (Cr) and aniline, can accumulate in suspended solids, sediments and aquatic organisms after polluting water bodies. Drinking such sewage for a long time is easy to induce cancer.
3. Solid waste pollution and human health Solid waste refers to solid substances discarded by human beings in production and life, such as waste rocks, industrial waste residue, waste plastic products and domestic garbage. It should be recognized that solid waste can only be used in a certain process or a certain aspect. In fact, it can often be used as a raw material for another production process. Therefore, solid waste is also called "misplaced raw materials". However, these "misplaced raw materials" often contain a variety of substances harmful to human health. If it is not used in time and piled up for a long time, it will pollute the ecological environment and cause harm to human health.
4. Noise pollution and human health
Noise is harmful to people in many ways: first, it damages hearing. Working in strong noise for a long time will reduce hearing and even cause noise deafness. Second, interfere with sleep. When people's sleep is disturbed by noise, they can't eliminate fatigue and recover their physical strength. Third, induce a variety of diseases. Noise can make people nervous, lead to an increase in heart rate and blood pressure, and even induce gastrointestinal ulcers, endocrine system dysfunction and other diseases. Fourth, it affects mental health. Noise can make people fidget, unable to concentrate on study and work, and easily lead to work-related injuries and traffic accidents. Therefore, we should take various measures to prevent and control environmental pollution so that all living things, including human beings, can live in a beautiful ecological environment.
The influence of environmental pollution on biology, environmental pollution and its three major effects
Environmental pollution often has carcinogenic, mutagenic and teratogenic effects on humans or mammals, which are collectively called "three effects". The harm of "three effects" usually takes a long time to appear, and some harm will even affect future generations.
1. Carcinogenesis
Carcinogenesis is the function of guiding people or mammals to get cancer. As early as 1775, British doctor Bert found that chimney sweepers were prone to scrotal cancer. He believes that scrotal cancer is related to frequent contact with coal ash. 19 15 years, Japanese scientists confirmed through experiments that coal tar can induce skin cancer. Among pollutants, substances that can induce cancer in humans or mammals are called carcinogens. Carcinogens can be divided into three categories: chemical carcinogens (such as nitrite, asbestos and dichloromethyl ether used in mosquito-repellent incense production), physical carcinogens (such as nuclear fusion of radium) and biological carcinogens (such as aflatoxin).
2. Mutation Mutation is the function of inducing gene mutation, chromosome structure variation or chromosome number variation in humans or mammals. If the germ cells of human beings or mammals mutate, it can affect the pregnancy process and lead to infertility or early embryonic death. If human or mammalian somatic cells mutate, it will lead to cancer. Common mutagens are nitrosamines, formaldehyde, benzene and dichlorvos.
3. Teratogenesis refers to the effect of acting on pregnant mothers, interfering with the normal development of embryos and leading to congenital malformation of newborns or young mammals. In the early 1960s, some deformed newborns appeared in Western Europe and Japan. Scientists have found that pregnant women take a sedative called thalidomide within 30 to 50 days after pregnancy, which has teratogenic effect. At present, the teratogens confirmed are methylmercury and some viruses.