Comprehensive assessment of PM10 from home heating using different appliances and biomass fuels: Chemical composition, oxidative potential, and ecotoxicity

The European Union has implemented policies to promote renewable energy, with an emphasis on biomass for heat generation. However, residential biomass combustion is a major source of particulate matter (PM 10 ), and its chemical constituents pose health concerns worldwide. This study characterised the organic and inorganic composition, oxidative potential (OP), and ecotoxicity of PM 10 indoors and outdoors during the operation of two heating appliances fuelled with different types of biomasses: a modern hydronic stove and a traditional wood stove. PM 10 concentrations were higher in the room equipped with the traditional system during the combustion of briquettes (95.9 ± 74.9 μg m -3 ) and firewood (50.1 ± 25.6 μg m -3 ), compared to the modern stove using pellets (27.1 ± 11.8 μg m -3 ) and olive stone (23.0 ± 4.5 μg m -3 ). While element oxides accounted for similar PM 10 mass fractions (7%), the wood stove produced higher levels of organic constituents, including carbonaceous fractions, polycyclic aromatic hydrocarbons (PAHs), quinones and saccharides. Significant correlations between OP assays and concentrations of PAHs, quinones and phenolic compounds were found in the room equipped with wood stove, with indoor to outdoor (I/O) ratios higher than 1. In contrast, I/O ratios below 1 were observed for OP in PM 10 samples collected during hydronic stove operation. Ecotoxicity assays using Aliivibrio fischeri classified indoor PM 10 from the wood stove as 'very toxic', whereas samples from the hydronic stove exhibited lower toxicity and OP levels. These findings highlight the need to reconcile renewable energy goals with air quality and public health. • Indoor PM 10 was higher during briquette and firewood combustion • I/O ratios >1 for room equipped with wood stove indicate dominant indoor PM 10 sources • Pellet stove use led to lower PM 10 , OP, toxicity and PM 10 -bound elements • All PM 10 samples from the wood stove room was classified as “very toxic” • PAHs, quinones and phenolic proved redox-active in OP assays from wood stove PM 10