Ecotoxicity induced by total, water soluble and insoluble components of atmospheric fine particulate matter exposure in Caenorhabditis elegans

Although PM2.5 could cause toxicity in environmental organisms, the toxicity difference of PM2.5 under different solubilities is still poorly understood. To acquire a better knowledge of the ecotoxicity of PM2.5 under different solubilities, the model animal Caenorhabditis elegans (C. elegans) was exposed to Total-PM2.5, water insoluble components of PM2.5 (WIS-PM2.5) and water soluble components of PM2.5 (WS-PM2.5). The physiological (growth, locomotion behavior, and reproduction), biochemical (germline apoptosis, and reactive oxygen species (ROS) production) indices, and the related gene expression were examined. According to the findings, acute exposure to these three components caused adverse physiological effects on growth and locomotion behavior, and significantly induced germline apoptosis or ROS production. In contrast, prolonged exposure showed stronger adverse effects than acute exposure. Additionally, the results of multiple toxicological endpoints showed that the toxicity effects of WIS-PM2.5 are more intense than WS-PM2.5, which means that insoluble components contributed more to the toxicity of PM2.5. Prolonged exposure to 1000 mg/L WS-PM2.5, WIS-PM2.5, and Total-PM2.5 dramatically altered the expression of stress-related genes, which further indicated that apoptosis, DNA damage and oxidative stress play a crucial part in toxicity induced by PM2.5.