Influence of ozone initiated processing on the toxicity of aerosol particles from small scale wood combustion. (February 2015)

• Record Type: Journal Article
• Authors: Nordin, Erik Z.; Uski, Oskari; Nyström, Robin; Jalava, Pasi; Eriksson, Axel C.; Genberg, Johan; Roldin, Pontus; Bergvall, Christoffer; Westerholm, Roger; Jokiniemi, Jorma; Pagels, Joakim H.; Boman, Christoffer; Hirvonen, Maija-Riitta
• Is Part Of: Atmospheric environment. Volume 102(2015)
• Page Start: 282
• Page End: 289
• Publication Date: 2015-02
• Subjects: Biomass combustion -- Polycyclic aromatic hydrocarbons -- Aging -- Cell studies; Air -- Pollution -- Periodicals; Air -- Pollution -- Meteorological aspects -- Periodicals; 551.51
• DOI: 10.1016/j.atmosenv.2014.11.068
• Languages: English
• ISSNs: 1352-2310

Abstract

Abstract: Black carbon containing emissions from biomass combustion are being transformed in the atmosphere upon processing induced by tropospheric ozone and UV. The knowledge today is very limited on how atmospheric processing affects the toxicological properties of the emissions. The aim of this study was to investigate the influence of ozone initiated (dark) atmospheric processing on the physicochemical and toxicological properties of particulate emissions from wood combustion. Emissions from a conventional wood stove operated at two combustion conditions (nominal and hot air starved) were diluted and transferred to a chamber. Particulate matter (PM) was collected before and after ozone addition to the chamber using an impactor. Detailed chemical and physical characterization was performed on chamber air and collected PM. The collected PM was investigated toxicologically in vitro with a mouse macrophage model, endpoints included: cell cycle analysis, viability, inflammation and genotoxicity. The results suggest that changes in the organic fraction, including polycyclic aromatic hydrocarbons (PAHs) are the main driver for differences in obtained toxicological effects. Fresh hot air starved emissions containing a higher organic and PAH mass-fraction affected cell viability stronger than fresh emissions from nominal combustion. The PAH mass fractions decreased upon aging due to chemical degradation. Dark aging increased genotoxicity, reduced viability and reduced release of inflammatory markers. These differences were statistically significant for single doses and typically less pronounced. We hypothesize that the alterations in toxicity upon simulated dark aging in the atmosphere may be caused by reaction products that form when PAHs and other organic compounds react with ozone and nitrate radicals. Highlights: The PAH fraction of biomass combustion aerosol decreases due to ozone aging. Nominal combustion PM induced less cell death compared to PM from hot air starved combustion. Aging alters the toxicological effects of biomass combustion PM.