Heavy Metal Pollution And Resident Health Risk Assessment Around Metal MINE

As society progresses, the number of dramatic global population growth, human be-ings are at an unprecedented scale and intensity of the development and use of resources, inevitably leading to many environmental problems, including the problem of heavy metal pollution of the environment is one of the most attention. There are environmental medi-cine research scholars believe that changing the distribution of physical and chemical prop-erties and environmental elements of human respiratory system, digestive system, repro-ductive system, and abnormal concentrations of trace elements such as health problems in space are not unrelated. So to clarify the relationship between the mining area around the heavy metal pollution and health risks among the local population for future regional plan-ning, environmental management and residents disease prevention has important theoretical and practical value.This thesis Suxian District of Hunan Province, land use change, heavy metal pollution, study issues related to residents’ health risks and mortality in relations with the residents of heavy metal pollution, designed by Suxian mine surrounding environment and residents’ health risks of heavy metal pollution evaluate the relevance of research, so as to lay the foundation for future prevention of heavy metal pollution and its effects on human health. The main results are as follows:1. Research on the relationship among the metal mines, land use and population dis-tribution of this study areaIn the process of economic development, metal mining, land use change and formed a cycle of positive feedback relationship between population distribution.Suxian district metal mining industry is developing rapidly, at present has formed a set of mining, smelting, and metal processing for the integration of mining and metallurgy processing area layout. Suxian district metal mining area of each villages and towns have differences, but due to the sustainable development of mining industry, the villages and towns are also affected to different extent, promote to transfer between the land use type. Suxian district from 1990 to 2010 and 5 km in metallic ore districts within the buffer show forestland, grassland and arable land decrease, the trend of construction land increase, metal construction land in the mining areas increasing trend is more obvious. Woodland reduced at the same time, the cultivated land area began to reduce large area, these phenomena are reflected the close contact between metal mining area and land use change, as well as the mining and industrial land where to live.Metal mining area within the buffer, and the average population density in 1-3 km buffer range, increased with the increase of buffer distance growth; Within the scope of the 3-10 km buffer, with the increase of buffer distance decreases. Population of more than 2000 people between 1990 and 2010 administrative villages are mainly distributed in suxian district in the Midwest near city, the southern plains region and the northern plains region. Population growth larger administrative villages more concentrated distribution in suxian district near the northern plains region, the Midwest city, central and southern region near the smelting area B and A near mining area within 1-3 km buffer, the trend of popula-tion increase is also very obvious.2. The current situation of the soil heavy metal and spatial distribution about this study areaDue to suxian district mining has a long history, especially the recent 20 years the mining industry development is very rapid, make the whole suxian district in soil, dust, and crop samples collected, the content of heavy metals in A high level, especially in the three functional areas A, B, C area near the samples especially the As and Cd concentration level, the content of Pb, at the same time, the concentration of heavy metal level with the increase of three functional areas buffer distance present decreasing trend. As and Cd in the farm-land soil a maximum of two kinds of heavy metal concentration, respectively, than the soil environment quality standard "(GB 15618-1995) Ⅱ grade standard of more than 10 times. That suxian district three functional areas within the scope of the soil by the As and Cd pollution is quite serious, it may be related to the soil pH value in the study area acidic (pH < 6.5); At the same time, the content of Pb in soil is more than the protection of agricultural production and human health standards (300 mg/kg). Overall suxian district three function-al areas of pollution risk level at A higher level of risk, from space four kinds of the pollu-tion degree of heavy metal pollution situation is inversely proportional to the distance of three functional areas, suxian district central mountain mining area A, high levels of pollu-tion, area and control area D, pollution levels are relatively low. The dust concentration of heavy metal level compared with the risk grade is more outstanding, shows that under the mining industry pollution at the same time, other factories around and car exhaust emis-sions also has certain influence on it.3. The study area residents health risk assessment of heavy metalsThrough hazard identification, dose-effect relationship assessment, exposure assess-ment and risk characterization of four footwork metal mining area surrounding residents health risk assessment model is established and calculated the residents health risk index of different consumption way, realizes the quantitative risk assessment to the health of the en-tire suxian district residents, and calculated the contribution of different ways and different kinds of heavy metals. Heavy metals exposed to the risk assessment results show that the human body through food intake, dust exposure to heavy metal elements of the risk of can-cer, which entered the body’s total THQs value, heavy metals in three functional areas of As, Pb, Cd THQs is far greater than 1, indicating that suxian district function area residents through diet and dust intake of heavy metals on the potential health risks. For the risk of cancer, given that the only for the As and Cd by breathing dust intake on the parameters of the standard, in this study through the carcinogenic risk of breathing dust intake of heavy metals in the range of 10-8～10-7, lower cancer risk threshold range of 10-6～10-4, but other ways of the risk of cancer is unclear, it still can not ignore the risk of cancer. At the same time, all the data shows that children’s risk index is higher than adults, so the children of a higher health risk. Total heavy metals not carcinogenic risk of size:Cd> Pb> As> Cu. Space scope, health risk of size:area A> area C> area B> area D.4. Research on the relationship between the mortality of residents and space distribu-tion of heavy metal mining area of this study areaSuxian district high mortality of hot spots, there are three main distribution in A min-ing and smelting B area and C zone around. Set up a buffer for suxian district mining area as a whole, it is found that with increasing the buffer distance, mortality is high the per-centage of the number of the village. Buffer 2 km range, high mortality of village of highly concentrated, which is high concentration of heavy metals areas; When the buffer distance is set to 7 km, the mortality is high number accounts for 50% of the number within the buffer village, village decreases in the concentration of heavy metals as the buffer within the population more than suxian district more than half of the rural population; The buffer after more than 7 km, with distance does not change significantly increased mortality is high proportion of village. Each area pollution impact on mortality rates meet certain index model, at the same time, the impact on the residents’ death and the scale of the mining, smelting and processing plants have a certain relationship and the kinds of heavy metals. The closer distance mining area, the greater the chance of contamination, so that the resi-dents’ health risk is greatly increased.Suxian district residents of lung cancer and liver cancer death spatial distribution of the two kinds of tumor are gathered near the three functional areas, and the aggregation of male residents is more clear. When the buffer radius is small, due to mining smelting sites are getting too close to the distance, the number of residents living nearby, there are fewer residents suffer from tumor death. With the expansion of the radius of the buffer, buffer ar-ea increasing, the number of residents and residents tumor death toll is rising. When the buffer distance is set to 5 km, the buffer within the scope of the male residents lung cancer deaths, women lung cancer deaths, male residents’ aggregation distribution to liver cancer deaths.Suxian district residents mortality and the local soil, dust, and no carcinogenic risk in-dex on the spatial distribution of has certain relevance, should cause enough attention, death from disease but limited to residents affected by multiple factors in different levels, so the heavy metal pollution and specific correlation between residents disease mortality remains to be further in-depth study.