Environmental Chemistry and Technology Program, University of Wisconsin-Madison, Madison, WI, 53706, USA.
Duke University, Civil and Environmental Engineering, 121 Hudson Hall, Durham, NC, 27708, USA.
Environ Pollut. 2019 Oct;253:190-198. doi: 10.1016/j.envpol.2019.07.003. Epub 2019 Jul 9.
Increased public awareness of the health impacts of atmospheric fine particulate matter (PM) has led to increased demand and deployment of indoor air cleaners. Yet, questions still remain about the effectiveness of indoor air cleaners on indoor PM concentrations and personal exposure to potentially hazardous components of PM. Metals in PM have been associated with adverse health outcomes, so knowledge of their sources in urban indoor and outdoor areas and how exposures are influenced by indoor air cleaners would be beneficial for public health interventions. We collected 48-h indoor, outdoor, and personal PM exposure samples for 43 homes with asthmatic children in suburban Shanghai, China during the spring months. Two sets of samples were collected for each household, one set with a functioning air filter placed in the bedroom ("true filtration") and the other with a non-functioning ("sham") air cleaner. PM samples were analyzed for elements, elemental carbon, and organic carbon. The major sources of metals in PM were determined by Positive Matrix Factorization (PMF) to be regional aerosol, resuspended dust, residual oil combustion, roadway emissions, alloy steel abrasion, and a lanthanum (La) and cerium (Ce) source. Under true filtration, the median indoor to outdoor percent removal across all elements increased from 31% to 78% and from 46% to 88% across all sources. Our findings suggest that indoor air cleaners are an effective strategy for reducing indoor concentrations of PM metals from most sources, which could translate into improved health outcomes for some populations.
公众对大气细颗粒物（PM）对健康影响的认识不断提高，导致对室内空气净化器的需求和使用不断增加。然而，关于室内空气净化器对室内 PM 浓度和个人对 PM 中潜在有害成分的暴露的有效性仍存在疑问。PM 中的金属与不良健康结果有关，因此了解其在城市室内和室外的来源以及室内空气净化器如何影响暴露情况，将有助于进行公共卫生干预。我们在中国上海郊区的 43 户有哮喘儿童的家庭中收集了春季为期 48 小时的室内、室外和个人 PM 暴露样本。每个家庭采集了两组样本，一组在卧室中放置了功能正常的空气过滤器（“真正过滤”），另一组则放置了功能不正常的空气净化器（“假过滤”）。PM 样本分析了元素、元素碳和有机碳。金属的主要来源通过正矩阵因子分析（PMF）确定为区域气溶胶、再悬浮粉尘、残余油燃烧、道路排放、合金钢磨损以及镧（La）和铈（Ce）源。在真正过滤的情况下，所有元素的室内到室外去除率中位数从 31%增加到 78%，所有来源的去除率中位数从 46%增加到 88%。我们的研究结果表明，室内空气净化器是减少大多数来源的室内 PM 金属浓度的有效策略，这可能会改善某些人群的健康状况。
