Ozone Aggravated the Toxicity of Fine Particulate Matter by Impairing Membrane Stability and Facilitating Particle Internalization.

The combined pollution of fine particulate matter (PM) and ozone (O) is increasing synergistically on a global scale, posing a serious threat to human health. However, the joint toxicity and the underlying mechanisms associated with co-exposure to PM and O remain poorly understood. Through complementary in vivo animal models and in vitro cellular assays, the results demonstrate that although there was no synergistic cytotoxicity effect between PM and O, the presence of O significantly enhanced the genotoxicity of PM by inducing severe DNA double-strand breaks. Furthermore, O exposure significantly exacerbated the bioaccumulation of PM by disturbing the cellular membrane integrity, thus leading to synergistic toxicity in bronchial cells and mouse lungs. Astaxanthin (AST) effectively antagonized the adverse effects of PM and O co-exposure by maintaining cell membrane integrity. These findings enhance our understanding of the pathophysiological mechanisms induced by co-exposure to PM and O, and provide a promising therapeutic strategy for treating respiratory diseases caused by unavoidable exposure to these pollutants.