환경시료 분석을 통한 라돈 분포특성 및 영향평가 방법론 연구

Abstract

Due to urbanization, industrialization modern citizens live most of the day indoors. As time for activities indoors gets longer, the importance regarding the pollution of indoor environment can be recognized and pollution of indoor environment can be said to be an important factor which has a harmful effect on human health. Contained in floors, ceilings or surrounding soil or walls of buildings, radon of indoor air pollution sources seeps into the building gap and comes into the body when breathing, increasing exposure dose and also causes various cancers. For this radon, we were to investigate the distribution characteristics of the radon concentration in soil and groundwater in Gwangju and carry out a radon investigation for Gwangju through the feature analysis of indoor radon concentration and building materials. Radon contained in groundwater through 25 tubular wells was measured and as a result, radon of 1 tubular well is 121.76 Bq/L, exceeding the WHO criterion (100 Bq / L) and that of 20 tubular wells exceeded U.S. EPA drinking water standard concentration(11.1 Bq/L) and higher radon concentrations were shown in tubular wells whose basement rock is granite. In the case of radon among soil pores, the measurement was performed targeting 28 points and average 25,000 Bq/m3 level was shown and some points showed maximum 125,365Bq/m3 and generally, higher radon concentrations were shown in granites. For building materials, three kinds of cement and three kinds of plaster tex were analyzed and plaster tex and cement showed the radon radiation of 47.07 ~ 232.78 Bq/kg·h and the radiation of 7.25 ~ 10.15 Bq/kg·h, respectively. Radium equivalent activity, external exposure hazard index and absorbed gamma dose rate through HPGe analysis also showed less than the standard value. For indoor radon, 10 households out of 74 households exceeded 74 Bq/m3, a US recommended home repair figure and even if one of them exceeded indoor air limit 148 Bq/m3, the average is 42.5 ± 29.8 Bq/m3, showing a figure lower than the national average. These radon distribution characteristics of Gwangju were examined and as a result, risk seems to be insignificant except for groundwater but given that most water intake points of groundwater exceed the US drinking water standard, drinking limit, reduction and measures seem to be urgent when approving and permitting groundwater tubular wells in granite bedrock areas.