Present situation of several kinds of environmental pollution

I. Current situation of marine pollution

At present, the marine environment in China is basically in good condition. However, in some coastal bays, estuaries and local sea areas, such as Dalian Bay, Liaohe Estuary, Jinzhou Bay, Bohai Bay, Laizhou Bay and Jiaozhou Bay, environmental pollution is serious. Some marine aquatic resources declined, the catch decreased, a few precious seafood were damaged, and the quality of some marine aquatic resources was affected; Some beaches were abandoned and the coastal environment was destroyed. As far as the sea area is concerned, the pollution along the Bohai Sea is more serious, followed by the East China Sea and the Yellow Sea, and the South China Sea is less polluted.

At present, the factors that pollute and damage the marine environment in China mainly include the following aspects:

1. Land-based pollutants: According to statistics of relevant departments, about 6 billion tons of industrial sewage and domestic sewage are discharged into the sea in coastal areas of China every year. Among domestic sewage, the East China Sea is the largest, followed by the South China Sea and Bohai Sea, and the Yellow Sea is the smallest. Among industrial sewage, the East China Sea is also the largest, accounting for 50% of the total. Followed by the Bohai Sea coast and the South China Sea coast, the Yellow Sea coast is the least.

2. Pollutants discharged by ships: China has more than 654.38 million motorboats, and tens of thousands of foreign ships enter our ports and sail through the waters under our jurisdiction every year, and a large amount of oily sewage is discharged into the sea. For example, 1979, a Brazilian tanker operated in Qingdao Oil Terminal, and ran 380 tons of oil at a time.

3. Pollution caused by offshore oil exploration and development: There are several large oil fields and more than a dozen petrochemical enterprises along the coast of China, and the amount of oil spilled, spilled and leaked is considerable, with the amount of oil entering the sea exceeding 654.38+10,000 tons every year.

4. Artificial dumping of waste pollution: In the past, the ocean was regarded as a big "garbage bin" and waste was dumped at will. For example, in Xiangliao Coast of Dalian Road, Huludao, Qingdao, Wenzhou, Zhanjiang and other places, garbage, slag and other wastes are piled up at the seaside or directly poured into the sea.

5. Unreasonable marine engineering construction and marine development: This has caused siltation in some deep-water ports and waterways and destroyed the ecological balance in some sea areas.

There are more than 200 types of pollution sources along the coast of China, including more than 100 in Bohai Sea and Yellow Sea, and about 100 in East China Sea and South China Sea. These pollution sources discharge important pollutants into the ocean.

There are petroleum hydrocarbons, heavy metal pollutants and organic pollutants. River carrying is the main way for pollutants to enter the sea.

Second, the present situation of soil pollution in China

1 heavy metal pollution in soil

With the intensification of industrial and urban pollution and the increase of types and quantities of agricultural chemicals, heavy metal pollution in soil is becoming increasingly serious, the pollution degree is increasing and the area is expanding year by year. Heavy metal pollutants have poor mobility and long retention time in soil, and cannot be degraded by microorganisms, which can eventually affect human health through media such as water and plants.

According to the national survey of sewage irrigation areas carried out by the Ministry of Agriculture of China, in the sewage irrigation areas of about 6.5438+0.4 million hm2, the land polluted by heavy metals accounts for 64.8% of the sewage irrigation areas, of which 46.7% is lightly polluted, 9.7% is moderately polluted and 8.4% is seriously polluted. China's grain production is reduced by100000 tons every year due to heavy metal pollution, and the grain contaminated by heavy metals is as high as120000 tons every year, resulting in a total economic loss of at least 20 billion yuan.

Judging from the current investigation of heavy metal pollution, the soil in most urban suburbs in China is polluted to varying degrees. According to the recent investigation data of our hospital, the area polluted by copper, mercury, lead and cadmium is 35.9% in a hilly area of Jiangsu Province 14000km2. The results of soil investigation by geological prospecting departments in Guangdong Province show that the land area of Xijiang River Basin is 6,543.8+0,000 km2, and the pollution rate is over 50%. Among them, the mercury pollution area is 1257km2, and the pollution depth is 40cm underground.

2. Soil organic pollution

At present, China's soil organic pollution is very serious, and its impact on agricultural products and human health has begun to appear. For example, in China, sodium pentachlorophenol was used to control schistosomiasis in the middle and lower reaches of the Yangtze River from 65438 to 0959, and the impurity dioxin has caused regional dioxin pollution, and the dioxin content in the sediments of Dongting Lake and Poyang Lake is very high. Organochlorine pesticides have been banned for nearly 20 years, and the residues in soil have been greatly reduced, but the detection rate is still high. The detection rate of bhc and DDT in vegetable soil in Guangzhou was 99% and 100%. The detection rate of HCH and DDT in farmland soil in Taihu Lake Basin is still 100%, and the highest residues in some areas are still above 1mg/kg. At the same time, with the acceleration of urbanization and industrialization, the organic pollution of soil near cities and industrial areas is becoming more and more serious. Nanjing Institute of Soil Research, Chinese Academy of Sciences recently investigated the agricultural soil around an iron and steel group and the soil near an industrial zone. The results showed that the average total amount of 15 polycyclic aromatic hydrocarbons in agricultural soil was 4.3mg/kg, and pollutants with more than four rings were mainly carcinogenic, accounting for about 85% of the total content, and only 6% of the sampling points were still at a safe level. The soil pollution near the industrial area is much higher than that of agricultural soil: polychlorinated biphenyls, polycyclic aromatic hydrocarbons, plastic plasticizers, herbicides, butachlor and so on. These highly carcinogenic substances can be easily detected in the soil around heavy industrial areas, which are many times higher than the national standards. The investigation results of 10 polycyclic aromatic hydrocarbons in urban and suburban soils of Tianjin showed that the content of polycyclic aromatic hydrocarbons in urban soils exceeded the standard most seriously, especially dicyclopentadiene and benzopyrene, a strong carcinogen. In Tibet, China, the content of PCBs in unpolluted soil is 0.625 ~ 3.50 1g/kg, while in Shenyang, it is 6 ~ 15 1g/kg.

3. Enrichment of organic pollutants in organisms

Because soil is the nutrient source of plants and some organisms, organic pollutants in soil will be transferred and migrated through the food chain. At present, animals and humans are polluted and threatened by organic pollutants.

In the process of transmission and migration along the food chain, the content of organic pollutants increases step by step, and its enrichment coefficient can reach an alarming level in all trophic levels. HCH and DDT were discontinued on 1983 as pesticides with high residue rate. With the passage of time, the residues of these two highly toxic pesticides were almost undetectable in the soil, but the contents detected in fish were nearly 100 times higher than those in the soil, while in the eggs of night herons and egrets, the contents were enlarged by 100 ~ 200 times. For example, the results of biological monitoring of birds in Taihu Lake showed that BHC was not detected in the mud at the bottom of Taihu Lake, and the DDT was 3.4 ng/g. Through biological enrichment of fish, BHC reached 28.5ng/g and DDT reached 270.7 ng/g, and finally reached 460.0ng/g and DDT reached 5626.7 ng/g in the eggs of night herons and egrets. These organic pollutants can be stored in the human body for a long time, and can be indirectly transmitted to the newborn or fetus through breastfeeding, or directly obtained through the placenta.

4. Soil radioactive pollution

In recent years, with the wide application of nuclear technology in industry, agriculture, medical care, geology, scientific research and other fields, more and more radioactive pollutants have entered the soil. These radioactive pollutants can not only directly harm the human body, but also enter the human body through the biological chain and food chain, producing internal radiation in the human body, damaging human tissues and cells, and causing diseases such as tumors, leukemia and hereditary diseases. For example, scientific research shows that the radiation hazard of radon daughters accounts for more than 55% of all radiation hazards suffered by human body, and the incubation period of lung cancer is mostly over 15 years. There are about 50 thousand cases of cancer caused by radon every year in China, and 23.7% of public lung cancer in Tianjin is caused by radon and its daughters.

Third, the current situation of air pollution in China

In recent years, although great achievements have been made in the prevention and control of air pollution in China, due to various reasons, the situation facing China's atmospheric environment is still very severe. The total amount of air pollutants discharged remains high. At present, the annual emission of sulfur dioxide in China is as high as 6.5438+0.857 million tons, the dust is 6.5438+0.65438+0.59 million tons, and the industrial dust is 6.5438+0.65438+0.75 million tons. Air pollution is still very serious. The atmospheric environmental quality of most cities in China exceeds the national standard. Among the 47 key cities in China, more than 70% of the cities' atmospheric environmental quality can't meet the second-class standard stipulated by the state; Among the 338 cities participating in environmental statistics, 137 cities, accounting for 40% of the statistical cities, are seriously polluted cities. The pollution in acid rain area is increasingly prominent. The acid rain area developed from a part of southwest China in 1980s to four major acid rain areas in southwest China, south China, central China and east China. The area covered by acid rain has accounted for more than 30% of China's land area, and China has become the third largest acid rain area in the world after Europe and North America. Acid rain pollution in Changde City is also very serious. 1996 When the acid rain frequency reaches 100%, it will be sour when it rains. Through the establishment of urban atmospheric environmental protection circle. Measures such as closing Cheng Zheng Brick and Tile Factory and dismantling small boilers with serious pollution have reduced the pollution of smoke and sulfur dioxide in the atmosphere, and the frequency of acid rain has decreased, but it is still as high as 4 1.6%.

According to the budget, in the first half of 2 1 century, China's energy development, utilization and consumption will increase greatly, and the characteristics of China's energy resources and the level of economic development determine that the coal-based energy structure will exist for a long time. Therefore, controlling soot air pollution will be a long-term main task in the field of air pollution control in China.

Three, China's water pollution status and effective solutions

Since the reform and opening up for more than 20 years, China's economy has developed rapidly, but the environmental pollution has become increasingly serious, especially the pollution of drinking water. At present, the insecurity of drinking water is mainly reflected in:

1。 Agricultural pollution sources include livestock manure, pesticides and fertilizers. Agricultural sewage contains high contents of organic matter, plant nutrients, pathogenic microorganisms, pesticides and fertilizers. According to relevant data, 1 100 million hectares of cultivated land and 2.2 million hectares of grassland use 1 104900 tons of pesticides every year. China is one of the countries with the most serious soil erosion in the world. The annual topsoil loss is about 5 billion tons, which leads to a large number of pesticides and fertilizers flowing into rivers, lakes and reservoirs with topsoil. With the loss of nutrients such as nitrogen, phosphorus and potassium, two-thirds of lakes are polluted by eutrophication in different degrees, which causes abnormal reproduction of algae and other organisms, changes in water transparency and dissolved oxygen, and thus leads to deterioration of water quality.

2。 Domestic pollution sources are mainly various detergents and sewage, garbage and feces used in urban life, mostly non-toxic inorganic salts. Domestic sewage contains a lot of nitrogen, phosphorus and sulfur, and there are many pathogenic bacteria. According to the survey, the domestic sewage discharge in China is 1998, that is,1840,000 tons.

3。 Industrial pollution, about13 of industrial wastewater and more than 90% of domestic sewage are discharged into water without treatment every year in China. More than 850 rivers in 1200 monitored in China are polluted, and more than 90% of urban waters are also polluted, resulting in the extinction of fish and shrimp in many river sections, and only 32.2% of rivers meet the national first-and second-class water quality standards. Pollution is developing from shallow to deep, groundwater and seawater near the sea are also being polluted, and the water we can drink and use is decreasing unconsciously. The increasingly serious water pollution has become the world's number one killer, posing a major threat to human survival and security, and becoming the main obstacle to human health, economic and social sustainable development. According to the investigation of international authoritative organizations, 8% of all kinds of diseases in developing countries are spread by drinking unsanitary water, which causes at least 20 million deaths worldwide every year. Therefore, water pollution is called "the world's number one killer".

In China, 82% people drink shallow wells and rivers, of which 75% are seriously polluted by bacteria, and the drinking water population seriously polluted by organic matter is about 654.38+0.6 billion. For a long time, people have always thought that tap water is safe and hygienic. However, due to water pollution, tap water is no longer safe and hygienic. According to a survey, there are as many as 222/kloc-0 chemical pollutants in tap water all over the world, some of which are confirmed as carcinogens or cancer promoters. Judging from the drinking standard of tap water, China is still at a low level. At present, waterworks can only treat river water or groundwater into drinking water by precipitation, filtration and chlorination. Chlorination of tap water can effectively kill bacteria and produce more halogenated hydrocarbon compounds. The content of these chlorine-containing organic compounds has doubled, which is the largest source of various gastrointestinal cancers in human beings. At present, the composition of urban pollution is very complicated. In addition to heavy metals, polluted water also contains many harmful residues, such as pesticides, fertilizers and detergents. Even if the tap water is boiled, the residue on it will not be driven away. However, the concentration of harmful substances in boiling water increases, which reduces the dissolved oxygen content beneficial to human health and increases carcinogens such as nitrite and chloroform. Therefore, the safety factor of drinking boiled water is not high. According to the latest data, only 23% of the residents in major cities in China have reached the hygienic standard, and the qualified rate of drinking water in small towns and rural areas is even lower. The urgent task of water pollution prevention and control is to ensure that drinking water is qualified. Therefore, water pollution monitoring should be strengthened and water supply source protection areas should be established.

People have realized that we can't develop the economy by destroying the ecological environment, and the cost is too high. China put forward the strategy of sustainable development of social economy and protection of people's health, and adopted a series of powerful measures to control water pollution. Never take the old road of pollution first and then treatment. For the sake of human health and survival, in order to have a clean water environment and protect water resources, we should start from now on!