Compositional profiles and pollution characteristics of volatile organic compounds in urban underground train stations

At critical transportation hubs in modern cities, the impact of volatile organic compound (VOC) pollution on public health in underground train stations is of great concern to society. However, the prevention and control of VOC pollution at underground train stations remain insufficiently explored owing to complex compositions and unclear sources. In this study, VOC samples were collected from 12 underground train stations in Chengdu to investigate their composition, pollution characteristics and influence on public health. The study detected 93 VOCs with a total VOC concentration of 80.64 ± 17.94 μg/m 3 . The primary sources of VOCs were organic solvent (23.31%), station emanation (13.33%), traffic emissions (10.96%), industrial emissions (21.49%) and human emanations (30.93%). Although underground train station VOCs were not found to pose non-cancer risks to the population, they contribute to low levels of cancer risks. This poses a significantly higher health risk to underground train station workers than to passengers. The findings offer a scientific foundation for developing effective pollution control strategies for VOCs at underground train stations and support the advancement of a healthy and sustainable environment for passengers.