Kang Choong-Min, Liu Man, Garshick Eric, Koutrakis Petros
Exposure, Epidemiology, and Risk Program, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA 02215, USA.
Pulmonary, Allergy, Sleep, and Critical Care Medicine Section, Medical Service, VA Boston Healthcare System; Channing Division of Network Medicine, Brigham & Women's Hospital; Harvard Medical School, Boston, MA 02130, USA.
Aerosol Air Qual Res. 2020;20(6). doi: 10.4209/aaqr.2020.01.0037.
Exposure to radioactivity inside homes potentially poses severe health risks which can be exacerbated by the interaction between radioactive particles and fine indoor particles; in particular, the presence of α particles are a key risk factor. Hence, in this study, particle radioactivity was concurrently measured in the family rooms and basements of 26 homes to assess its concentrations and identify its sources, both indoors and outdoors, across two seasons. The levels of radon, air ions, and particle radioactivity, which included short- and long-lived α-activity (SLA and LLA, respectively), varied greatly but were substantially higher in the basements. Also, particle radioactivity-as well as PM and sulfur concentrations-were lower during the heating season. SLA was associated with radon, which was consistently of indoor origin, whereas LLA was more strongly related to the sulfur measured in indoor PM, which is a proxy of outdoor infiltration. A regression model adjusted for sulfur and SLA also indicated a predominance of outdoor sources, likely due to the short residence time of indoor particles. Our results suggest that radiation in homes originates from both the decay of indoor radon and the infiltration of outdoor radioactivity.
家庭内部的放射性暴露可能会带来严重的健康风险，放射性粒子与室内细颗粒物之间的相互作用会加剧这种风险；特别是，α粒子的存在是一个关键风险因素。因此，在本研究中，同时测量了26户家庭客厅和地下室的粒子放射性，以评估其浓度，并确定其在两个季节中室内和室外的来源。氡、空气离子和粒子放射性水平，分别包括短寿命和长寿命α放射性（SLA和LLA），变化很大，但在地下室中显著更高。此外，在供暖季节，粒子放射性以及颗粒物和硫的浓度较低。SLA与氡有关，氡始终来自室内，而LLA与室内颗粒物中测量的硫关系更强，硫是室外渗透的一个指标。针对硫和SLA进行调整的回归模型也表明主要是室外来源，这可能是由于室内颗粒物的停留时间较短。我们的结果表明，家庭中的辐射既来自室内氡的衰变，也来自室外放射性物质的渗透。
