Stanley Fintan K T, Zarezadeh Siavash, Dumais Colin D, Dumais Karin, MacQueen Renata, Clement Fiona, Goodarzi Aaron A
Departments of Biochemistry and Molecular Biology and of Oncology (Stanley, Zarezadeh, Goodarzi), Robson DNA Science Centre, Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary; Canadian Association of Radon Scientists and Technologists (C. Dumais, K. Dumais, MacQueen); Health Technology Assessment Unit (Clement), O'Brien Institute for Public Health, Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alta.
CMAJ Open. 2017 Mar 28;5(1):E255-E264. doi: 10.9778/cmajo.20160142. eCollection 2017 Jan-Mar.
The inhalation of naturally occurring radon (222Rn) gas from indoor air exposes lung tissue to α-particle bombardment, a highly mutagenic form of ionizing radiation that damages DNA and increases the lifetime risk of lung cancer. We analyzed household radon concentrations and risk factors in southern Alberta, including Calgary, the third-largest Canadian metropolis.
A total of 2382 residential homes (2018 in Calgary and 364 in surrounding townships) from an area encompassing 82% of the southern Alberta population were tested for radon, per Health Canada guidelines, for at least 90 days (median 103 d) between 2013 and 2016. Participants also provided home metrics (construction year, build type, foundation type, and floor and room of deployment of the radon detector) via an online survey. Homes that were subsequently remediated were retested to determine the efficacy of radon reduction techniques in the region.
The average indoor air radon level was 126 Bq/m3, which equates to an effective absorbed radiation dose of 3.2 mSv/yr. A total of 1135 homes (47.6%) had levels of 100 Bq/m3 or higher, and 295 homes (12.4%) had levels of 200 Bq/m3 or higher; the range was less than 15 Bq/m3 to 3441 Bq/m3. Homes built in 1992 or later had radon levels 31.5% higher, on average, than older homes (mean 142 Bq/m3 v. 108 Bq/m3). For 90 homes with an average radon level of 575 Bq/m3 before mitigation, radon suppression successfully reduced levels to an average of 32.5 Bq/m3.
Our findings show that radon exposure is a genuine public health concern in southern Alberta, suggest that modern building practices are associated with increased indoor air radon accumulation, legitimatize efforts to understand the consequences of radon exposure to the public, and suggest that radon testing and mitigation are likely to be impactful cancer prevention strategies.
吸入室内空气中天然存在的氡气（222Rn）会使肺组织受到α粒子轰击，这是一种极具致突变性的电离辐射形式，会损害DNA并增加患肺癌的终生风险。我们分析了加拿大艾伯塔省南部（包括加拿大第三大城市卡尔加里）的家庭氡浓度及风险因素。
根据加拿大卫生部指南，2013年至2016年间，对涵盖艾伯塔省南部82%人口区域内的2382处住宅（卡尔加里有2018处，周边乡镇有364处）进行了至少90天（中位数为103天）的氡检测。参与者还通过在线调查提供了房屋指标（建造年份、建筑类型、基础类型以及氡探测器的部署楼层和房间）。对随后进行修复的房屋进行重新检测，以确定该地区氡减排技术的效果。
室内空气中氡的平均水平为126贝克勒尔/立方米，这相当于每年3.2毫希沃特的有效吸收辐射剂量。共有1135处住宅（47.6%）的氡水平达到或高于100贝克勒尔/立方米，295处住宅（12.4%）的氡水平达到或高于200贝克勒尔/立方米；范围为低于15贝克勒尔/立方米至3441贝克勒尔/立方米。1992年及以后建造的房屋，其氡水平平均比旧房屋高31.5%（平均142贝克勒尔/立方米对108贝克勒尔/立方米）。对于90处缓解前平均氡水平为575贝克勒尔/立方米的房屋，氡抑制措施成功将水平降至平均为32.5贝克勒尔/立方米。
我们的研究结果表明，氡暴露在艾伯塔省南部是一个切实的公共卫生问题，表明现代建筑做法与室内空气中氡的积累增加有关，使了解氡暴露对公众影响的努力具有合理性，并表明氡检测和缓解措施可能是有效的癌症预防策略。
