Research progress on cardiovascular effects of traffic-related air pollution and noise: Evidence from population-based and mechanism studies

Traffic-related air pollution and noise are becoming increasingly prominent issues in the context of urbanization, both of which are modifiable environmental risk factors for cardiovascular diseases. Those two kinds of traffic-related pollution may have combined effects on the cardiovascular system of human beings, but the biological mechanisms by which they may interact have not been elucidated yet. Thus, we reviewed the research progress based on published population-based and mechanism studies from five aspects, including oxidative stress, inflammatory response, nervous system activation and stress hormones, coagulation dysfunction, and endothelial dysfunction, providing indications for possible common biological pathways. Future studies can construct co-exposure scenarios for traffic-related air pollution and noise to explore their common biological mechanisms in the cardiovascular system by examining the reviewed pathways to provide a scientific basis for the protection of susceptible populations. In addition, the effect modification by individual characteristics and underlying diseases may merit further exploration.