| Radon is the only radioactive inert gas in nature, it is one of the19main carcinogens which published by WHO, it is widespread in human living environment, and influence the health of human body. The effect degree of radon for human and the environment geological conditions have a close relationship. Xinping copper mine existed radioactive geological background, mining activities have aggravated the radioactive environmental impact on the ground. In this paper, from the effects of radioactive radon on human health, combined with the pathways of radon diffusion migration from underground to ground, and on the basis of the mining exploitation status, investigate the radioactivity in main production and living area of this mining. Compare the natural background level of Yuxi City with this measurement results, draw the following conclusions:the present mining area surface gamma radioactive level is higher than the level at beginning of the mine repaired, and close to the natural background, but these two are within the range of natural background levels;when we were monitoring the level of indoor radon concentration in the living area, we found radon concentration in Room102,Building9is2.49times as large as in ventilated work area. what's more, it exceed the national control standards for indoor radon concentration.Combining the basic features of radon,law of migration and proliferation, and people's life style in mining district, the paper analyze the major sources of indoor radon and the reasons for increasing of radon concentration' level in sealed room. It can draw a conclusion that a crack in the floor caused by mining and the soil of high radon background are the main reason that cause the indoor radon concentration rise.According to the diffusion of the Fick medium gas, using mathematical principle modeling the residential, classifying and simulating the indoor floor whether have cracks or crannies,and obtaining the simulation results under the condition with no cracks, and discuss the related factors of the distribution of radon in the indoor, provides people with the guidance of the anti-radon and radon drop.(1)In the condition of no indoor cracks:when the terrestrial background radon concentration is the same, select each three different section in the X and Y axis, the simulation results show, at different heights, the phenomenon of the radon concentration stratification is obvious, and with the increase of the height, the radon concentration showed a decreasing trend; take6different period of high section in the Z axis direction; at the same height of the same level, radon concentrations showed a uniform distribution, the radon concentration increased with height showed a decreasing trend too. Increase the ground background concentration of radon, radon concentration in indoor distribution with the former, just at the same height and the same level, the value of the radon concentration increase.(2)In the condition of exist indoor cracks:discuss the concentration distribution of indoor radon under the impact of cracks, and the distribution of radon which people are breathing in height of150cm. Simulate the indoor cracks in different locations, cracks in the upper appear concentration anomaly, the changes of abnormal position and crack position are consistent. In the contour map of150cm, the cracks radon decreasing around the oval; analysis of different convection velocity in horizontal and vertical in the air influence on the distribution of indoor radon, found that increase advection speed will increase the height of the diffusion of radon, so change the horizontal convection velocity will change the ability of the radon diffusion to the surrounding. Taking into account the distribution of radon in different heights, selected and compared6sections in different heights, radon concentration with height increase decreasing, and just in different sources, the same high level of radon concentration have difference.Finally,Through the study provides methods to reduce indoor radon concentrations are as follows:①Before selected building location must carry on the radioactive geological investigation to the groundsill.②Building materials should try to select waste rock of the mining area west waste rock field and the sand of tailings Tail or to choose building materials and decorative materials with low radio nuclides and low radon exhalation rates;③Radionuclide detection of water sources on a regular basis.for water, use water installations.④enhance indoor ventilation, and air exchange rate;⑤domestic fuel use in outdoor or open the hood. |
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