Air pollution causing oxidative stress

Air pollution remains a major factor for adverse health effects and premature death worldwide. Particulate matter with aerodynamic diameter ≤2.5 μm (PM_2.5), mainly originating from combustion processes, is considered most toxic. The respiratory and cardiovascular system are particularly affected. Despite all research efforts, the causative relations of air pollutants and exposure-associated health effects are not yet fully established. Recent studies using different methodologies have consistently shown peroxides and reactive oxygen species (ROS) to be crucial mediators of particle toxicity. This review is an excerpt of results from experimental studies and methodological developments of the past 2 years that enhanced our understanding of oxidative molecules in particles, their transmission to the target organ, and the molecular pathways generating ROS in physiological and pathological processes. Further multidisciplinary research towards predicting toxicology from particle-related ROS transmitted to the target organ is required.