Study on the air pollution in typical transportation microenvironment: Characteristics and health risks

The concentration of formaldehyde in micro-traffic atmospheric environment (including buses, cars, bus stations, and traffic artery) of Lin'an City was carefully investigated. The results showed that the formaldehyde average concentration was 0.0162 mg/m³ in the buses, 0.0225 mg/m³ in the cars, 0.0047 mg/m³ in the West Bus Stations, and 0.0133 mg/m³ in the East Bus Stations. The concentration of formaldehyde along the traffic artery decreased with the height increased. From 0 to 140 cm, the formaldehyde concentration decreased from 0.031 to 0.018 mg/m³. The formaldehyde concentration decreased when far away from the traffic artery. When the distance reached 200 m, the formaldehyde concentration decreased from 0.018 to 0.005 mg/m³. Based on the health risk assessment model, using 1 hr as the average retention time, the average health risk in buses, cars, and West/East Bus Stations was 2.106 × 10⁻⁴, 2.925 × 10⁻⁴, and 1.157 × 10⁻⁴, respectively.