Environmental problems and their harm
Environmental problems and their harm, there are many environmental problems in life, human survival can not be separated from the air, and the current environmental problems are very harmful to people's health, making the air very turbid and blocking the sun. The following share environmental problems and their hazards.
Environmental problems and their hazards 1 (1) acute hazards: the concentration of pollutants is very high in a short time, or the combination of several pollutants can cause acute hazards 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. In addition, pollutants have a great influence on heredity.
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.
Harm of heavy metals to organisms Some heavy metals such as manganese, copper and zinc are essential trace elements for biological activities, but most heavy metals such as mercury and lead are toxic to biological activities. 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.
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.
Harm of eutrophication 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.
Environmental problems and their harm. Environmental pollution will cause direct damage and influence to the ecosystem, such as desertification and forest destruction, and will also cause indirect harm to 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.
Environmental pollution problems have appeared in different degrees all over the world, including atmospheric pollution, marine pollution and urban environmental problems with global influence. With the globalization of economy and trade, environmental pollution is becoming more and more international, and the problem of transboundary movement of hazardous wastes is the outstanding performance in this respect.
1, harm to human health
People need to breathe air to keep alive. An adult breathes about 20,000 times a day and inhales 1.5 ~ 20 cubic meters of air. Therefore, polluted air has a direct impact on human health.
Air pollutants do harm to human body in many ways, such as respiratory system damage, physiological dysfunction, digestive system disorder, nervous system abnormality, mental decline, cancer, disability and so on. People call the smoke of this disaster "the smoke of killing". When the concentration of pollutants in the atmosphere is high, it will cause acute pollution poisoning, or aggravate the symptoms, and even kill thousands of people within a few days. In fact, even if the concentration of pollutants in the atmosphere is not high, breathing this polluted air all the year round will cause chronic bronchitis, bronchial asthma, emphysema, lung cancer and other diseases.
Environmental pollution and cancer. A large number of research data show that environmental pollution is an extremely important cause of cancer, and it is an important part of comprehensive cancer prevention and control measures to take comprehensive measures to effectively control environmental pollution relying on the strength of the whole society.
2. Damage to plants
Air pollutants, especially sulfur dioxide and fluoride, are very harmful to plants. When the concentration of pollutants is high, it will cause acute damage to plants, damage to the surface of plant leaves, or directly cause leaves to wither and fall off; When the concentration of pollutants is not high, it will cause chronic damage to plants, make the leaves of plants fade, or have no harmful symptoms on the surface, but the physiological functions of plants are affected, leading to the decline of plant yield and deterioration of quality.
3. Weather and climate effects
The influence of air pollutants on weather and climate is very significant, which can be explained from the following aspects:
(1) Reduce the amount of solar radiation reaching the ground: A large number of smoke particles discharged into the atmosphere by factories, power stations, automobiles, household heating equipment, etc. make the air very turbid, which blocks the sunlight and reduces the amount of solar radiation reaching the ground.
(2) Increase atmospheric precipitation: Many particulate matter emitted by large industrial cities have the function of condensation nuclei of water vapor.
③ Acid rain: Sometimes, the rain falling from the sky contains sulfuric acid. This kind of acid rain is the oxidation of sulfur dioxide, a pollutant in the atmosphere, to form sulfuric acid, which falls with the precipitation in nature; Sulfuric acid rain can destroy large areas of forests and crops, corrode and destroy paper products, textiles and leather products, degrade metal antirust coatings and reduce their protective effects, and also corrode and pollute buildings.
(4) Raise the atmospheric temperature: Over large industrial cities, the air temperature near the ground is higher than that in the surrounding suburbs due to a large amount of waste heat discharged into the air. This phenomenon is called "heat island effect" in meteorology.
⑤ Impact on global climate: Since 20 10, people have gradually noticed the impact of air pollution on global climate change. After research, people think that carbon dioxide plays an important role in various air pollutants that may cause climate change. Carbon dioxide can absorb long-wave radiation on the ground and raise the air temperature near the ground, which is the so-called "greenhouse effect". Some experts believe that the increase of carbon dioxide content in the atmosphere will melt the ice in the north and south poles in a few years, leading to global climate anomalies.
Environmental problems and their harm. What are the environmental pollution losses?
1, adverse effects of environmental pollution on organisms
Environmental pollution has a very adverse effect on the growth, development and reproduction of organisms. When the pollution is serious, the morphological characteristics and survival quantity of organisms will change obviously. The harm of environmental pollution to organisms is described from four aspects: acid rain, harmful chemicals, heavy metals and water eutrophication.
2. Environment and human health
With the increasingly serious environmental pollution, many people breathe polluted air, drink polluted water and eat agricultural products grown from polluted soil all day, and the noise echoes in their ears ... Environmental pollution seriously threatens human health.
3. The influence of environmental pollution on biology, environmental pollution and "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.
Second, what harm does environmental pollution do to people?
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. 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 from mining industry, industrial waste residue, discarded 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, the damage to 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.