Fine Brown Carbon Aerosol Emitted by Wood Pyrolysis - New Harmful Tracers and Cytotoxicity in Human Lung Cells

Furthermore, reduction in metabolic activity, cellular membrane damage, death phenotype, and morphology were investigated. Cytotoxicity of solvent-extractable BrC increased in the order water < methanol < acetone. Descriptor-based screening showed that cytotoxicity was likely associated with lipophilic compounds capable of membrane partitioning and redox-active moieties, contributing to oxidative stress.

The harmful BrC tracers identified included benzoic and cinnamic acids, methoxyphenols, quinols, and natural compounds such as flavonoids, coumarins, indoles, and plant sterols. The highest contributors to baseline narcosis were 3-hydroxybenzoic, salicylic, <i>p</i>-coumaric acids, benzene-1,2,4-triol, methylxanthoxylin, methyl ester of heteropeucenin, coniferylaldehyde, and agelasine. These results demonstrate that chemical composition strongly governs BrC toxicity.

Moreover, by combining comprehensive molecular-level characterization with simple descriptors, it is possible to identify potentially harmful compounds within complex BB emissions. The presented approach provides a framework for identifying potentially harmful components of BrC aerosols and supports improved assessment of their health impacts.