A Review of Personal Exposure Studies in Asian Public Transport Microenvironments: Lessons Learned and Future Directions

Abstract

Abstract This paper reviews personal exposure and air pollutant levels in Asian city transport microenvironments. It examines PM10, PM2.5, PM1, CO2, CH2O, and TVOC exposure in cars, buses, walking, and subways/trains. PM2.5 was the most studied pollutant, followed by PM10, PM1, CO2, and TVOC. Limited research focused on CH2O exposure. Exposure concentrations varied among cities and transport modes. Motor vehicle emissions, traffic, road dust, and open bus doors were primary exposure sources. Train stations and outdoor environments contributed to pollutant levels inside trains. Factors influencing exposure included ventilation, travel conditions, seat location, vehicle type, and meteorology. Inhalation exposure doses varied by mode. The review recommends standardized measurements, improved ventilation, filters, clean energy, and public education to reduce exposure. More research is needed in diverse Asian cities. This review aids policymakers, researchers, and advocates for air quality and public health.