汕头市中心城区天然辐射外照射水平及居民暴露剂量的调查

目的掌握汕头市中心城区居民生活环境天然辐射外照射水平并估算居民暴露剂量。方法根据《环境地表吖辐射剂量率测定规范》（GB／T14583—93）和《辐射环境监测技术规范》（HJ／T61—2001）的方法要求，采用AT1123X-γ辐射检测仪测量汕头市中心城区居民生活环境吖辐射水平，估算居民暴露剂量。结果居室内天然叮辐射水平范围为143～275nGy／h，平均值为203．1nGy／h，标准差为21．3nGy／h；居室外天然1辐射水平范围为90-252nGy／h，平均值为163．4nGy／h，标准差为26．3nGy／h；室内外天然叮辐射所致人均年有效剂量当量约1196．7ixSv／a，集体年有效剂量当量约为2028．4人·Sv／a。结论汕头市中心城区居室内天然γ辐射平均水平比广东省室内天然Y辐射平均水平（18．0×10-8Gy／h）略高，居室外天然1辐射平均水平比广东省室外天然γ辐射平均水平（13．2×10μGy／h）偏高；汕头市中心城区天然1辐射所致人均年有效剂量当量比广东省人均年有效剂量当量（970μSv／a）略高，但明显高于全国平均值（590μSv／a）和世界典型值（500μSv／a）；汕头市中心城区居民生活环境天然辐射外照射水平仍属于正常放射性的天然本底水平。

Investigation on the external exposure level of natural radiation and the exposure dose of residents in downtown area of Shantou City

[ Objective ] To understand the external exposure level of natural radiation in living environment of downtown area of Shantou, estimate the exposure dose of residents. [ Methods ] According to ＂ Norm for the measurement of environmental terrestrial gamma-radiation dose rate （ GB/T 14583-93 ） ＂ and ＂ Technical criteria for radiation environmental monitoring （ HJ/T 61-2001 } ＂ , the γ radiation level in living environment was measured by AT1123X-γ radiation detector, the exposure dose of residents was esti- mated. [ Results] The range of natural ~/radiation level in living room was 143 ~ 275 nGy/h, the average was 203.1 n Gy/h and the standard deviation was 21.3 nGy/h. The range of natural γ radiation level outdoor was 90 - 252 nGy/h, the average was 163.4 nGy/h and the standard deviation was 26.3 nGy/h. The pre capita average annual effective dose equivalent made by natural γ radi- ation indoor and outdoor was 1196.7 μSv/a, the collective annual effective dose equivalent was 2 028. 4 person γ Sv/a. [ Conclusion] The average level of natural ~/radiation in living room of Shantou city is slightly higher than that of Guangdong Prow ince /18.0 x 10-s Gy/hl , and the average level of natural γ radiation outdoor is slightly higher than that of Guangdong Province （ 13.2 x 10-s Gy/h）. The pre capita average annual effective dose equivalent made by natural γradiation in the downtown area of Shantou city is slightly higher than that of Guangdong Province （ 970 μ Sv/a } , but significantly higher than the national average （ 590 μ Sv/a } and the world typical value （ 500 μ Sv/a }. The external exposure level of natural radiation in the living environment of downtown area of Shantou city is still the normal natural background level of radioactivity.