Indoor exposure to radon and external gamma radiation in Manyoni area, Central Tanzania

• 作 者: Shovi Sawe Germana Mlay
• 机 构: Tanzania Atomic Energy Commission University of D
• 出 处: 第七届国际天然放射性物质研讨会
• 发表日期: 2013年9期
• 关键词: radon gamma baseline data

　　Uranium exploration activities are ongoing in various parts of Tanzania and uranium mining and milling may start in the near future.Manyoni district located in Singida central Tanzania is one of the areas where uranium exploration is going on.In order to provide some baseline information about the area before mining and milling,the indoor radon concentrations and gamma dose rates have been estimated in thirty houses located in Manyoni area.For radon concentration measurements,a portable radon gas monitor (ALPHAGUARD) capable of detecting radon gas in the range of 2 Bq/m3 to 2,000,000 Bq/m3 was used.Gamma dose rates were measured using a digital dose rate meter capable of reporting cumulative dose over a given period of time.Results show that radon concentrations in some houses were above the indoor radon action levels of 100 Bq/m3,148 Bq/m3 and 200 Bq/m3 recommended by WHO,USEPA,and ICRP,respectively.Assuming the 7000 hours per year indoor (an occupancy of 80 %) recommended by the ICRP,the recorded gamma dose rates in some houses may lead to annual doses of up to 2 mSv.