Concentration, composition, and exposure contributions of fine particulate matter on subway concourses in China. (15th April 2021)

• Record Type: Journal Article
• Authors: Ji, Wenjing; Liu, Chenghao; Liu, Zhenzhe; Wang, Chunwang; Li, Xiaofeng
• Is Part Of: Environmental pollution. Volume 275(2021)
• Publication Date: 2021-04-15
• Subjects: Iron -- Exposure -- Metro system -- Indoor -- Outdoor; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2021.116627
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Concentrations of airborne metal-rich particles are typically higher on subway platforms and in subway tunnels than in ambient air. The subway concourse is an area of direct air exchange with both platforms and the outside environment, but few researchers have measured the concentrations and composition of fine particles on subway concourses. We characterized the concentrations and composition of fine particles on six subway concourses in Nanjing, China in both summer and winter. We used a respiration rate-adjusted microenvironment exposure model to estimate the contribution of a 6-h work period to daily mean exposure to fine particulate matter of subway workers and compared the estimate with those for general indoor and outdoor workers. We found that particle concentrations were typically higher on the station concourses than in ambient air. The most abundant elements composing the particles were Fe, S, Ca, Si, and K in both subway concourses and reference ambient air, but their contents varied greatly between indoor and outdoor air. The indoor/outdoor ratios of Fe, Cu, and Mn were highest, and subway workers were disproportionately exposed to these three metals. The mean daily exposure dose to Fe was 44.8 μg for subway workers, approximately five times the exposure dose of indoor and outdoor workers. Daily exposure doses of Cu, Mn, V, Sr, As, Co, Sn, and Cr were also higher for subway workers. The quality of indoor air at subway stations is therefore of occupational health concern and strategies should be formulated to reduce worker exposure. Graphical abstract: Image 1 Highlights: Fine particle concentrations were higher on subway concourses than in ambient air. The I/O ratio of Fe was the largest, followed by Cu and Mn in subway station. The most abundant elements were Fe, S, Ca, Si and K. Daily doses of heavy metals were higher for subway workers than indoor and outdoor workers. Occupational exposure to Fe contributes 86%, 24% and 36% for subway, indoor and outdoor workers. Abstract : Main findings: The composition of PM2.5 on subway station concourses was characterized and the respiration rate-adjusted daily exposure to metallic elements was assessed for three occupational exposure groups.