| Xiangshan uranium mine is the largest volcanic rock-hosted uranium mine in China, the uranium deposit is on a large scale. The main crop is rice. The activiities of Uranium mining will not only bring large number of radionuclide and radon gas toxic, but also large amounts of heavy metals. Heavy metals can turn into the human body through environment of water, air and soil, they damage to human health. Therefore, environment management is not only the influence of radionuclide, but also heavy metal pollution.Heavy metal Cd damage to human liver and other organs. It damages to the human respiratory system.The results of the Cd content in paddy soil and surface water carried out the following research:(1)The minimum content of Cd in 237 soil samples of whole study area is 0.05 mg/kg, the maximum content is 1.81 mg/kg, the geometric average content is 0.23 mg/kg. The minimum content of Cd in 59 surface water samples of whole study area is <0.002ug/kg, the maximum content is 0.511ug/kg, the geometric average is 0.487 mg/kg. The geometric average content of Cd in paddy soil of unexploited area is 0.15mg/kg, the geometric average content of Cd in the surface water of unexploited area is 0.195ug/kg. The geometric average content of Cd in paddy soil of control area is 0.133mg/kg,the geometric average content of Cd in the surface water of control area is 0.142ug/kg. The high content of Cd in paddy soil and surface water samples are mainly distributed in mining area, the Cd content in paddy soil and surface water of mining area is higher than the Cd content unexploited area.The Cd contents of paddy soil and surface water in exploiting area were influenced by mining activities and uranium ore transportation,but had little effect。Surface water samples Cd content of tailing are higher than the surface water environment quality standards.(2)The region of Cd content in the paddy soil of mining area is 0.05mg/kg-0.516 mg/kg, the average content is 0.23 mg/kg. The average content is 2.3times and 3.11 times to soil background values of Jiangxi province 0.10 mg/kg and the values of national soil background 0.074mg/kg. The region of Cd content in surface water of the mining area is 0.002ug/kg-1.09 ug/kg, the average content of Cd is 0.178ug/kg, is 1.08 times to the content of Cd in surface water of unexploited area,but is less than the surface water environment quality standards And the variation coefficient of Cd in paddy soil and surface water of mining area is higher than the unexploited area. The variation coefficient of Cd in surface water of mining area are 1.21 times to unexploited area. It has a strong influence to the contents of Cd in paddy soil and surface water by mining and transportation. The order of Cd average content in paddy soil of mining area are Shazhou>tailings>Lian Tang country>Yangjia country>Dinglong country.(3)The Cd content in surface soil samples of four soil profiles is higher than the Cd content in the bottom soil samples.The bottom Cd content in soil is higher than soil background values of Jiangxi province and the national soil background value.The high content in bottom soil show that Cd content of background values in this area is higher.(4)According to single factor pollution index evaluation method showed: among the 237 samples in soil of whole study area, 45.15% samples are mild pollution,35.86% samples are middle level pollution, 11.39% samples are heavy pollution. Among 237 samples in mining regions most samples belong to mild pollution, 36.29% samples are mild pollution,32.07% samples are middle level pollution,7.59% samples are heavy pollution. 30 samples in unexploited area are all mild pollution. Samples in the control area are mild pollution. Cd pollution index size of various regions in the paddy soil respectively are mining area >whole study> unexploited area >control area.12 soil samples of four soil profiles show two soil samples of tailings region are mild pollution;the surface soil samples of the rest three soil profiles are middle level pollution,the bottom soil samples are light pollution.(5)The analysis of Cd content in paddy soil and the surface water showed that the coupling relationship between the Cd content in paddy soil and surface water has a close relationship, generally speaking with Cd contents in paddy soil turn higher the Cd content in the surface water are also increased.(6)The pollution levels of Cd in paddy soil depends on contaminating by mining activities,paddy planting,and dropping ore, slag formation by transportation. |
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