摘要
目的调查个旧地区居室内氡（^222Rn）、钍射气（^220Rn）及其子体水平，明确钍射气的剂量贡献。方法考虑住宅类型和地理分布因素，从个旧市郊某村选取建筑结构有代表性的50户住宅的主卧室，采用氡-钍射气鉴别探测器测量氡、钍射气浓度，用沉积率装置测量钍射气子体浓度。其中14间居室采用连续性氡测量探测器和α谱氡、钍射气鉴别探测器测量氡、钍射气浓度，空气采样滤膜结合CR-39探测器测量钍射气衰变产物浓度，碘化钠闪烁计数器测量地表γ剂量率。结果50间居室的氡浓度为32～498Bq／m^3，平均136Bq／m^3；钍射气浓度为39～7908Bq／m^3，平均3297Bq／m^3；钍射气子体浓度为2．0～23．9Bq／m^3，平均10．2Bq／m^3。钍射气子体衰变产物致居民年平均有效剂量大于氡子体衰变产物的平均年有效剂量（2．9mSv vs 1．6mSv）。结论个旧市郊部分居室室内钍射气及其子体浓度高，钍射气子体的剂量贡献要高于氡子体的剂量贡献。在个旧开展氡致肺癌危险评价研究应当考虑钍射气子体的剂量贡献。
Objective To measure the concentration of indoor thoron and its daughter products as well as indoor radon in selected houses in Gejiu area, Yunnan province. Methods 50 houses were selected in a village south to Gejiu city. Radon and thoron concentrations were measured using passive integrating radon-thoron discrimination detectors. Concentrations of thoron daughter products were determined with thoron progeny deposition rate devices. 14 houses from the 50 selected houses were surveyed with short-term measurements. Results Thoron concentrations ranged from 39 to 7 908 Bq/m^3 with an arithmetic mean of 3 297 Bq/m^3. Many houses with high thoron concentrations were found. Indoor equilibrium equivalent thoron concentrations （ EECTn ） varied from 2. 0 to 23.9 Bq/m^3 with an arithmetic mean of 10. 2 Bq/m^3. Indoor radon concentrations ranged from 32 to 498 Bq/m^3 with an arithmetic mean of 136 Bq/m^3. Conclusion The local residents living in Gejiu areas are exposed to high thoron and radon, the annual effective dose from thoron daughter products was larger than that from radon daughter products, 2. 9 mSv/a vs 1.6 mSv/a. Further dosimetric and epidemiological studies are needed to clarify the effects from residential exposure to both thoron and radon.
出处
《中国职业医学》
CAS
北大核心
2008年第3期211-213,共3页
China Occupational Medicine
基金
科学技术部2002年度社会公益研究专项基金部分资助(2001DA10001)
