Impact of a long-distance volcano eruption on aerosol water-soluble organics composition and cytotoxic effects over monocytes

Volcano eruptions significantly impact air quality, due to their large emissions of particulate matter, SO₂ and trace metals [1,2]. Exposure to these emissions can exert adverse effects on cardiorespiratory health as well as causing dermal and ocular irritation [2]. As such, it is important to understand which characteristics of volcanic air pollution are responsible for these reported negative health outcomes. To this end, two sets of PM_2.5 samples were collected at a suburban location during a period impacted by volcanic activity and a reference period. The structural features of these aerosol WSOM samples were assessed through liquid-state NMR spectroscopy, whereas their cytotoxic effects were evaluated on the THP-1 human monocytic cell line.

Overall, a total of 25 structures were identified in the WSOM samples, of which 12 were common to both samples. The WSOM samples effectively activated THP-1 monocytes and enhanced their expression of adhesion molecules. This effect over cells suggests that some WSOM components may accelerate the formation of atherosclerotic plaques, potentially elevating the risk of cardiovascular diseases. Nonetheless, and even though both samples presented toxicological properties, overall, the volcanic activity did not appear to cause a significant alteration in the chemical properties and cytotoxic effects over monocytes of the fine aerosol WSOM.

Thanks are due to FCT/MCTES for the financial support to CESAM (UID Centro de Estudos do Ambiente e Mar (CESAM) + LA/P/0094/2020) to iBiMED (UIDB/04501/2020, DOI: https://doi.org/10.54499/UIDB/04501/2020 and project reference UIDP/04501/2020, DOI: https://doi.org/10.54499/UIDP/04501/2020) and for a PhD grant (2020.05804.BD; DOI: https://doi.org/10.54499/2020.05804.BD) through national funds and the European Social Fund.

[1] Ilyinskaya, E., Schmidt, A., Mather, T.A., et al., Earth Planet. Sci. Lett. 472, 309–322.

[2] Stewart, C., Damby, D.E., Horwell, C.J., et al., Bull. Volcanol., 2022, 84.