The impact of household air cleaners on the chemical composition and children's exposure to PM2.5 metal sources in suburban Shanghai

• Published in: Environmental pollution (1987) 2019-10, Vol.253, p.190-198
• Main Authors: Brehmer, Collin, Norris, Christina, Barkjohn, Karoline K., Bergin, Mike H., Zhang, Junfeng, Cui, Xiaoxing, Zhang, Yinping, Black, Marilyn, Li, Zhen, Shafer, Martin, Schauer, James J.
• Format: Article
• Language: English
• Subjects: Air pollution; Indoor air quality; Particulate matter; Positive matrix factorization; Source apportionment
• ISSN: 0269-7491
• DOI: 10.1016/j.envpol.2019.07.003

Increased public awareness of the health impacts of atmospheric fine particulate matter (PM2.5) has led to increased demand and deployment of indoor air cleaners. Yet, questions still remain about the effectiveness of indoor air cleaners on indoor PM2.5 concentrations and personal exposure to potentially hazardous components of PM2.5. Metals in PM2.5 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 PM2.5 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. PM2.5 samples were analyzed for elements, elemental carbon, and organic carbon. The major sources of metals in PM2.5 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 PM2.5 metals from most sources, which could translate into improved health outcomes for some populations. [Display omitted] •Six sources of elements in indoor, outdoor, and personal exposure PM2.5 were found.•Air cleaner can reduce indoor concentrations of elements from most PM2.5 sources.•Personal exposure to some elements and sources was reduced by the air cleaner.