1. Urban Air Pollution
(1) Air Environment Quality Standards
The evaluation standard adopts GB 3095-1996 "Ambient Air Quality Standards". The standard is divided into three levels, sulfur dioxide, nitrogen oxides, total suspended particulate matter at all levels of standard values are shown in Table 11.2.1.
Table 11.2.1 Air Quality Standards (GB3095-1996) Unit: mg/L (standard state)
The urban ambient air quality functional areas are divided into three categories. Class I for nature reserves, scenic spots and other areas requiring special protection, the implementation of standards for the first standard. The second type of areas are residential areas, mixed commercial and transportation residential areas, cultural areas, general industrial areas and rural areas identified in the town planning, the implementation of standards for the second standard. Type III areas are specific industrial areas, and the enforcement standard is Level III. In the evaluation of ambient air quality in each city of the province, SO2, NOx and TSP evaluation implement the secondary standards in (GB 3095-1996).
(2) urban air quality
Comparing the changes in the comprehensive index of urban ambient air pollution in Henan Province from 1991 to 1999 (Table 11.2.2), the urban air quality in the province, as measured by the GB 3095-1996 level II standard, generally remained in compliance with the standard or close to exceeding the standard.17 provincial municipalities monitored in 1997 Among the 17 provincial municipalities monitored in 1997, Puyang, Xinyang, Hebi, Luohe, Shangqiu, Xuchang, Xinxiang 7 cities are better, the average value of the composite index is less than 1. Among them, Puyang is the best, the average value is only 0.33, SO2, NOx, Total Suspended Particulate Matter (TSP) have reached or close to the first-class air quality standards. Anyang, Jiyuan, Zhengzhou, Jiaozuo, Luoyang, Kaifeng, Pingdingshan, Sanmenxia 8 cities air quality is poor, the average value of 1.15 ~ 1.67. In Zhengzhou City, for example, the average value of SO2 is 0.053 mg/m3, which is up to the second level standard; the annual average value of NOx is 0.074 mg/m3, which exceeds the second level standard; and the annual average value of TSP is 0.469 mg/m3, which exceeds the third level standard. Its main pollutant is TSP, which is the ****same characteristic of air pollution in most cities in the province (Table 11.2.3).
Table 11.2.2 Year-by-year changes in the composite index of ambient air pollution in cities of Henan Province
Table 11.2.3 Table of monitoring data of major pollutants of ambient air in cities of Henan Province in 1997
Comparing the composite index of pollution in major cities of Henan Province in 1992 and 1997 (Table 11.2.4), it can be seen that most major cities There is a significant improvement in air quality, with Xinxiang, Shangqiu, Nanyang and Hebi dropping from exceeding the standard and seriously exceeding the standard to reaching the standard. Only Pingdingshan City has seen an increase in pollution due to the increase in thermal power generation equipment, which is also reflected in the acid rain levels. The percentage of acid rain in Zhengzhou City decreased from 2.2% in 1992 to 1.47% in 1997; while in Pingdingshan City, it increased from 0.8% in 1992 to 2% in 1997.The results of acidity monitoring of 25 precipitation samples from 10 cities in 1999 showed pH values ranging from 5.11 to 8.16. Judging by the standard of pH << 5.6, the incidence of acid rain in our province is 1.2%, and the overall degree of occurrence is relatively mild. The higher incidence of acid rain was in Luoyang City and Nanyang City, where the incidence was 3.5% and 11.1%, respectively.
Increased indoor air pollution is a problem that cannot be ignored in the booming development of urban civil buildings in recent years. Formaldehyde, toluene, xylene, styrene, benzopyr, carbon dioxide, carbon monoxide and other harmful gases produced by indoor decoration and cooking can reach more than 500 kinds, which directly jeopardize human health.
Table 11.2.4 Comparison Table of Composite Index of Air Pollution in Major Cities of Henan Province (1992, 1997)
According to the data of Beijing Children's Hospital, 90% of the pediatric leukemia patients have some kind of relationship with indoor decoration. Particularly alarming is the radioactive radon gas which can cause cancer. According to the results of a survey in Zhengzhou City in 1996, in the vicinity of faults and in the soil, radon gas concentration is high in the area, indoor radon gas concentration can reach 100 to 200 Bq/m3, 4 to 8 times higher than the normal value (environmental value). It is an invisible killer of human health. Granite, marble slabs and lightweight bricks made of slag used for certain indoor decoration also have a certain degree of radioactive contamination. The cancer incidence rate of a school in Zhengzhou is significantly higher than that of other urban universities, which is closely related to the high concentration zone of radon gas.
2. Urban Noise Pollution
(1) Environmental Noise Evaluation Standards
The Standard for Environmental Noise in Urban Areas (GB 3096-93) stipulates the maximum limits of environmental noise in five types of urban areas (Table 11.2.5).
Table 11.2.5 Environmental Noise Standards for Urban Areas (Unit: dB(A))
The applicable areas of each type of standard are:
The Class 0 standard applies to convalescent areas, high-class villas, high-class hotels, and other areas in need of quiet, located in the suburbs and the countryside of this type of area, respectively, according to the implementation of the standard is more stringent than the Class 0 5 dB;
Class 1 The standard applies to residential, cultural and educational institutions mainly in the area, the rural residential environment can refer to the implementation of the standards in this category; 2 standards for residential, commercial and industrial mixed areas;
3 standards for industrial zones;
4 standards for urban areas on both sides of the road traffic arterials, through the urban areas on both sides of the inland waterways, through the city on both sides of the railroad trunk lines, the main and secondary trunk line The background noise (refers to the noise level when not passing trains) limit value of the area also implements the standards of this category.
(2) Urban Noise Situation
According to the 1998 monitoring data of 16 major cities in the province, the average equivalent sound level of urban area noise in the province is 56.9 dB(A). Among them, three cities, Xinyang, Luoyang and Jiyuan, exceeded 60 dB(A). The average equivalent sound level of urban road traffic noise was 69.4 dB(A), with 39.3% of the sections exceeding 70 dB(A). Xinyang, Kaifeng, Sanmenxia, Hebi cities exceeded the number of sections greater than 60%, the other functional areas exceeded the daytime 1 to 3 dB (A), nighttime 5 to 7 dB (A).
(3) electromagnetic radiation pollution
As of June 1997, the province **** 1043 units have electromagnetic radiation sources. Mainly for radio and television transmission communications, radar, equipment, etc. and navigation transmission equipment, as well as industry, scientific research, medical field in the application of medium and high-frequency equipment, power system high-voltage transmission and substation equipment, power transportation equipment. *** counted 9011 sets of various types of electromagnetic radiation equipment, radiation power density from a few mW/cm2 to more than 10 mW/cm2, the emission frequency from dozens of kHz to more than 10 GHz. these devices on the densely populated urban areas produce electromagnetic radiation pollution, the main hazard is the interference with broadcasting, communications and navigation signals, while its thermal and non-thermal effects on human health caused by the damage.
3. Solid Waste Pollution
(1) Industrial and Mining Waste
Mainly thermal power generation slag, fly ash, metallurgical slag, red mud and chemical waste. Mining waste mainly for the gangue and other minerals and mining waste rock and mineral tailings, etc. In 1998, the province's solid waste *** produced 38272500 t. Coal gangue for the first major category of solid waste. Our province's annual output of about 100 Mt of coal, gangue annual production of about 18.4 ~ 20 Mt, accounting for the province's total solid waste 2 / 3. 1 Mt occupies an area of 2.5 hm2, the annual new land 46 ~ 50 hm2.
Pingdingshan annual production of gangue 0.7 ~ 1.5 Mt, fly ash 1.18 Mt, there have been gangue mountain 73, to 2000, the gangue accumulated 79.62 Mt, occupies nearly 50 hm2. 79.62 Mt, occupying nearly 200 hm2; another iron ore and other mine slag and tailings occupying 212 hm2.
Jiaozuo City, the annual output of gangue 1 Mt, fly ash 0.8 Mt, to 2000, the accumulation of gangue 41.85 Mt, occupying an area of 104.2 hm2. Electricity, steam and hot water industry for the generation of solid wastes the second largest, the annual generation of solid wastes also more than 10 Mt.
According to statistics, as of the end of 1998, the province's cumulative stockpile of industrial and mining solid waste 240.918 Mt, covering an area of 215,000 hm2.
(2) urban living garbage
With the accelerated process of urbanization and the rapid growth of the city and the outskirts of the city has become an important source of pollution. According to the statistics of Zhengzhou City, the average daily production of garbage per person 1.17 kg, the province's 38 cities in 1998 the total amount of annual domestic garbage reached 5.25 Mt. And the annual production of domestic garbage at a rate of 5% to 8% growth rate, predicted that the province's urban population of 30.47 million people in 2005, the annual production of domestic garbage will be up to 13.1 Mt. Some of the cities in Henan Province, the annual amount of garbage production in detail, see Table 11.2.6.
(3) Hazards of Solid Waste
In addition to occupying land, solid waste also produces direct or indirect pollution to air, surface water, soil and shallow groundwater. For example, the organic content of municipal waste accounts for 51% to 83%. Its decay causes air odor and flies and mosquitoes breeding. Plastic products accounted for 8% ~ 17%, both the formation of "visual pollution", landfill and long-term difficult to degrade, spoil the soil. Coal gangue piled up for a long time often spontaneous combustion and self-explosion, air pollution, or directly cause personal injury. Such as 1988 Jiaozuo City, a gangue pile of self-explosion, so that the way 11 secondary school students were injured, of which 9 died of failure to rescue. Solid waste by the rain shower, its organic, inorganic salts and toxic heavy metals and so on into the soil and shallow groundwater will cause serious pollution. Mercury content in the gangue can exceed the soil 2 to 3 times, a large number of mineralized material leaching caused by soil crusting. Some data show that the content of arsenic, mercury and chromium in the groundwater under urban garbage dumps can exceed the drinking water standard by 12.5 to 540 times. Mine processing tailings are also prone to leakage pollution events, such as in April 1988 Shaanxi Jinduicheng thousands of tons of tailings leakage and in August 1996 Songxian Qiyugou gold mine 200,000 m3, tailings leakage events, are caused by the downstream of the water and soil serious pollution. Xiao Qinling gold mining area Shuangqiao River in the lead exceeds the standard 3.4 times, mercury exceeds the standard 15.7 times, that is, and gold mining and metallurgy have a close relationship.
Table 11.2.6 Annual amount of domestic garbage generated in some cities of Henan Province
The distribution of industrial solid waste in Henan Province by industry is shown in Table 1 1.2.7.
The emission and treatment of industrial solid waste in Henan Province in 1997 is shown in Table 1 1.2.8.
Table 11.2.7 Distribution of industrial solid waste in Henan Province by industry
Table 11.2.7 Distribution of industrial solid waste in Henan Province by industry
The distribution of industrial solid waste in Henan Province by industry is shown in Table 1 1.2.8. Distribution of solid waste
(Quoted from Kong Zhaoying et al., 2000)
Table 11.2.8 Emission and treatment of industrial solid waste in Henan Province in 1997