Emission factors of environmentally persistent free radicals in PM2.5 from rural residential solid fuels combusted in a traditional stove

Real-World Emission Characteristics of Environmentally Persistent Free Radicals in PM2.5 from Residential Solid Fuel Combustion

“…The EFs (g•kg −1 ) of the PM 2.5 and carbon components from solid fuel combustion were calculated using the carbon mass-balance method. 26,27 The EFs of EPFRs (EF EPFRs ) were calculated using the following equation, as reported by Zhao et al 28 =…”

“…The EFs (g·kg –1 ) of the PM 2.5 and carbon components from solid fuel combustion were calculated using the carbon mass-balance method. , The EFs of EPFRs (EF EPFRs ) were calculated using the following equation, as reported by Zhao et al where EF EPFRs and EF PM2.5 are the EFs of EPFRs (spins·kg –1 ) and PM 2.5 (g·kg –1 ), respectively; RC EPFRs is the concentration of EPFRs based on the PM 2.5 mass (spins·g –1 ).…”

Formation of Environmentally Persistent Free Radicals from the Irradiation of Polycyclic Aromatic Hydrocarbons

“…Incomplete combustion of organic materials, such as fuel and biomass, provides the main source of EPFRs. Previous studies have reported EPFR concentrations of 10 16 to 10 18 spins g –1 in various samples, including cigarette smoke, biochars, coal, electronic waste, residential and vehicle fuel, and industrial activity. ,− The organic substituents in these materials can also react during combustion and form a variety of fused, multi-ringed aromatic compounds known as polycyclic aromatic hydrocarbons (PAHs). ,,− The formation of PAHs has been previously explained by various reaction pathways, e.g., hydrogen abstraction acetylene addition, hydrogen abstraction vinylacetylene addition, and methyl addition cyclization. ,− These pathways involve free radical reactions, which can form other free radical molecules. Due to the aromaticity of the PAH present in combustion particles, the resulting free radicals become resonance-stabilized in the structure of the particles. ,,,,,,, Because PAHs are ubiquitous in combustion particles, PAHs and PAH-derived EPFRs can be transported into the body and lodged in the heart and lungs, contributing to chronic disease, cardiopulmonary dysfunction, and a decrease in life expectancy. ,,− …”

Household characteristics associated with environmentally persistent free radicals in house dust in two Australian locations

“…The association between air pollution and adverse health outcomes has been long established, but the causal mechanism(s) behind this association are still uncertain (Kelly 2003, Kelly & Fussell 2015, Mudway et al 2020, Risom et al 2005). Recent studies propose a role for environmentally persistent free radicals (EPFRs) as a potential inducer of oxidative stress (OS), which may be the missing connection between air pollution and detrimental health impacts (Dugas et al 2016, Gehling & Dellinger 2013, Guan et al 2021, Pan et al 2019, Ruan et al 2019, Sly et al 2019, Vejerano et al 2018, Xu et al 2021, Xu et al 2020, Zhao et al 2021).…”

“…EPFRs are formed during combustion processes and are present on small particulate matter (PM) with a mass median aerodynamic diameter of 2.5 micrometres or less (PM 2.5 ), usually generated from traffic-related air pollution (TRAP), residential activities, industrial burning, and cigarette smoking (Chen et al 2019, Gehling & Dellinger 2013, Sly et al 2019, Vejerano et al 2018, Wang et al 2020, Xu et al 2021, Zhao et al 2021). EPFRs are particularly concerning as they are free radicals that can persist in the environment and in biological systems for prolonged periods of time (Pan et al 2019, Sly et al 2019, Vejerano et al 2018, Xu et al 2021, Zhao et al 2021).…”