Urban stormwater cytotoxicity: Influence of land use, toxicity mechanism and implication for reuse safety

The study explored the toxicity of urban stormwater sourced from different land uses on Chinese hamster ovary (CHO) cells. By investigating the effects of stormwater from residential, commercial, highway, and grassland roads on CHO cells, the research highlights the significant impact of land use on stormwater toxicity. The results demonstrate that residential road stormwater, which is likely to contain a high concentration of pollutants due to human activities, has the most pronounced inhibitory effect on CHO cells. Conversely, grassland road stormwater, which is relatively clean and has low traffic and human activity, has lower toxic effects on CHO cells. The study further explored the possible toxicity mechanisms of urban stormwater, alterations in metabolic pathways related to RNA dysfunction and DNA double-strand break, as well as the induction of oxidative stress in cells exposed to urban stormwater, leading to an increase in malondialdehyde (MDA), reactive oxygen species (ROS), reactive nitrogen species (RNS) and carbonyl protein levels, resisting the negative influence due to the urban stormwater toxicity. These findings contribute to the understanding of the toxicity effects of urban stormwater and provide useful information for ensuring the safety of stormwater reuse. This study also highlights the need for continued research to better understand the complex interactions between rainfall and catchment characteristics, ultimately leading to safer and more sustainable stormwater management practices.