Emissions from a modern log wood masonry heater and wood pellet boiler: Composition and biological impact on air-liquid interface exposed human lung cancer cells

Abstract

The consumption of wood fuel is markedly increasing in developing and industrialized countries. Known side effects of wood smoke inhalation manifest in proinflammatory signaling, oxidative stress, DNA damage and hence increased cancer risk. In this study, the composition and acute biological impact of emissions of state-of-the-art wood combustion compliances: masonry heater (MH) and pellet boiler (PB) were investigated. Therefore A549 cells were exposed to emission aerosols in an automated air-liquid interface exposure station followed by cytotoxicity, transcriptome and proteome analyses. In parallel, aerosols were subjected to a chemical and physical characterization. Compared to PB, the MH combustion at the same dilution ratio resulted in a 3-fold higher particle mass concentration (PM2.5) and deposited dose (PB: 27 ± 2 ng/cm 2 , MH; 73 ± 12 ng/cm 2). Additionally, the MH aerosol displayed a substantially larger concentration of aldehydes, polycyclic aromatic hydrocarbons (PAH) or oxidized PAH. Gene ontology analysis of transcriptome of A549 cells exposed to MH emissions revealed the activation of pro-inflammatory response and key signaling cascades MAP kinase and JAK-STAT. Furthermore, CYP1A1, an essential enzyme in PAH metabolism, was induced. PB combustion aerosol activated the proinflammatory marker IL6 and different transport processes. The proteomics data uncovered induction of DNA damage-associated proteins in response to PB and DNA double-strand break processing proteins in response to MH emissions. Taking together, the MH produces emissions with a higher particle dose and more toxic compounds while causing only mild biological responses. This finding points to a significant mitigating effect of antioxidative compounds in MH wood smoke.

Photochemical transformation of residential wood combustion emissions: dependence of organic aerosol composition on OH exposure

“…served for typical ambient semivolatile oxygenated aerosol, with a van Krevelen slope of −0.5, which can be interpreted as a result of simultaneous fragmentation and acidgroup addition (Ng et al, 2011). Furthermore, the changes in OS C 's were similar to those previously observed for ambient aerosol aged extensively in a potential aerosol mass (PAM; Kang et al, 2007) OFR (OS C of up to 2; Ortega et al, 2016). The OS C 's of RWC exhaust aged in a PAM OFR have, however, been notably lower than observed here ( Fig.…”

“…As an alternative, oxidation flow reactors (OFRs) with continuous sample flow have been increasingly utilized in combustion emission studies (Bruns et al, 2015a;Czech et al, 2017;Pieber et al, 2018). To achieve similar to or higher oxidant exposures than chambers in shorter residence times, OFRs have been used with high ozone concentrations together with high-intensity, low-wavelength UV lamps to generate OH-radical concentrations orders of magnitudes higher than those of smog chambers (Kang et al, 2007;Ihalainen et al, 2019;Simonen et al, 2017). Thus, OFRs enable measurements with better temporal resolution, which is a benefit when assessing the ageing of aerosols from dynamic sources, such as batchwise logwood combustion.…”

Variation of Absorption Ångström Exponent in Aerosols From Different Emission Sources

“…The effect of exhaust pretreatment before the measuring instruments was HELIN ET AL. -Saksa et al (2016-Saksa et al ( , 2018 Buses Diesel, hybrid and alternative fuels Controlled driving conditions at depot area Pirjola et al (2015), Saarikoski et al (2017) Buses Diesel In-traffic conditions Järvinen et al (2019) Coal-fired power plant Coal and coal mixed with wood pellets Stack gas measurements with and without cleaning Mylläri (2018), Mylläri et al (2017Mylläri et al ( , 2019 Wood burning Three logwood species and softwood pellets Modern masonry heater, pellet boiler Czech et al (2018), Kanashova et al (2018), Kortelainen et al (2018), Reda et al (2015) Wood burning Birch logwood Sauna stove Tissari et al (2019) (Aakko-Saksa et al, 2016;Amanatidis et al, 2018). In addition, a potential aerosol mass (PAM) chamber was used to simulate aerosol aging and secondary aerosol formation (Kang et al, 2007;Lambe et al, 2011).…”

Toxicity of Water- and Organic-Soluble Wood Tar Fractions from Biomass Burning in Lung Epithelial Cells

“…Polyphenolic compounds, which are formed in wood combustion or pyrolysis and found mostly in organic extracts, have antioxidant properties. − The log K ow coefficient of these compounds is higher in the organic-soluble fraction than in the water-soluble fraction, supporting the increased antioxidant content in the organic-soluble extract than in the water-soluble extract. These antioxidant properties can mitigate oxidative effects from other constituents. − For example, PM emissions from log wood stoves show a considerably lower acute cytotoxicity than diesel engine emissions at comparable particle deposition concentrations.…”