While toxicity of carbonaceous air particulate matter (PM) has been recognized, especially that resulting from combustion such as diesel exhaust (DE) and wood smoke (WS) PM, the active substances are still unidentified due to this system’s complexity. Polycyclic aromatic hydrocarbons (PAHs) and recently also their derivatives have been known for their toxicity and are often considered a main contributors to the PM toxicity. Thus in our initial work we have studied the contribution of these species to the proinflammattory effect of combustion PM. We have extracted PM using sonication with methanol; to confirm the completeness of extraction, we have added an additional step of Soxhlet extraction. The extracts arere then fractionated using solid phase extraction into three different polarity fractions. Over 120 PAH-derived compounds have been identified and semi-quantified. Both native DEPM and WSPM caused a concentration-dependent increase in IL-6 and IL-8 release and cytotoxicity of bronchial epithelial lung cells (BEAS-2B). The majority of the IL-6 release and cytotoxicity induced upon exposure to the most polar (methanol) SPE fraction is possibly related to hydroxy-PAHs, carboxy-PAHs observed along with nitro-amino-PAHs in DEPM. Nevertheless, the biological effects induced by the polar fractions could not be attributed only to the occurrence of PAH-derivatives. To further narrow down the list of components responsible for PM toxicity, two high pressure exhaustive extraction protocols were designed differing in the polarity sequence of extraction solvents: 1) a series of organic solvents (at 100 °C) complemented by extraction of water soluble species; 2) ambient water followed by steps with 50, 100, and 150 °C and then completed with an organic solvent. The PM fractions were characterized based on the organic carbon content, distribution of PAHs and their oxidation products as well as other major classes of compounds including alkanes, carboxylic acids, aldehydes and high molecular weight species using a broad range of analytical methods developed in our laboratory including thermal desorption-pyrolysis-gas chromatography with mass spectrometry. The comprehensive chemical characterization results will be evaluated with regard to biological effects in different cell models.<br/>

Essential approaches to investigation on chemical origins of proinflammatory components of diesel exhaust and wood smoke particulate matter

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.