State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of the Chinese Academy of Sciences, Beijing 100049, China.
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of the Chinese Academy of Sciences, Beijing 100049, China; School of Environment, Hangzhou Institute for Advanced Study, University of the Chinese Academy of Sciences, Hangzhou 310000, China.
J Hazard Mater. 2021 May 5;409:125014. doi: 10.1016/j.jhazmat.2020.125014. Epub 2020 Dec 31.
Environmentally persistent free radicals (EPFRs) are a type of emerging contaminants. The EPFR species in airborne particulate matter are similar to carcinogenic tar paramagnetic species in cigarettes that can cause DNA damage. However, understanding on daily EPFR exposure levels and risks are lacking currently. We used personal aerosol exposure monitors worn by volunteers to assess EPFR exposure in a spatio-temporal, non-static manner. Daily individual exposure to EPFRs for urban residents in Beijing, China ranged from 1.11 × 10 to 7.42 × 10 spins/m during the heating period (winter) and from 4.79 × 10 to 7.76 × 10 spins/m during the non-heating period (summer). Carbon-centered radicals were dominant in winter, while oxygen-centered radicals were dominant in summer because of higher atmospheric oxidizing capacity contributing to oxidation reactions. Coal combustion in winter is a key influencing factor in EPFR exposure levels. An intuitional assessment was used to evaluate the inhalation risks of EPFRs by converting their concentrations in inhaled particulate matter to equivalents in cigarettes smoked. The assessment concluded that one urban resident may, on average, inhale the equivalent of 46 cigarettes per day in EPFRs. The health risks of these free radicals, especially during winter, should be researched in depth.
环境持久性自由基（EPFRs）是一种新兴污染物。空气中颗粒物中的 EPFR 种类与香烟中致癌的顺磁焦油种类相似，可导致 DNA 损伤。然而，目前对于日常 EPFR 暴露水平和风险的了解还很缺乏。我们使用志愿者佩戴的个人气溶胶暴露监测仪，以时空非静态的方式评估 EPFR 暴露。在中国北京，城市居民在供暖期（冬季）的个人 EPFR 日暴露量范围为 1.11×10 到 7.42×10 自旋/m，在非供暖期（夏季）的日暴露量范围为 4.79×10 到 7.76×10 自旋/m。冬季以碳中心自由基为主，而夏季以氧中心自由基为主，这是因为大气氧化能力较高，促进了氧化反应。冬季的煤炭燃烧是 EPFR 暴露水平的一个关键影响因素。我们采用直观评估方法，将吸入颗粒物中 EPFR 浓度转换为香烟烟雾中的等效浓度，评估 EPFR 的吸入风险。评估结果表明，城市居民平均每天可能会吸入相当于 46 支香烟的 EPFR。这些自由基的健康风险，尤其是在冬季，应深入研究。
