The overlooked toxicity of non-carcinogenic polycyclic aromatic hydrocarbons

Recent climate change-induced wildfires and nuclear energy phasing-out policies have fostered atmospheric emissions of polycyclic aromatic hydrocarbons (PAHs).PAHs are pollutants produced by natural and anthropic processes under thermal treatment of organic matter, e.g. in fires and sedimentary rocks (Henner et al. 1997, Lichtfouse et al. 1997).They occur widely in the environment from trace levels, e.g. in polar ice, to high concentrations in oil spills.They have been found in aerosols, soils, sediments, waters, meterorites, coal, petroleum, bitumen and living organisms.Surprisingly, out of the 16 polycyclic aromatic hydrocarbons defined as 'priority' polluants for toxicity evaluation, ten light homologues have been poorly investigated because they did not show obvious carcinogenic effects.Here, we argue that the toxicity of light PAHs has been overlooked (Fig. 1).