Characterization and source apportionment of particulate matter and COin Chinese subway stations with varying platform screen door forms.
Source: PubMed, NCBI / U.S. National Library of Medicine
With the vigorous development of subway systems, particulate matter (PM) and COin subway stations is raising increasing concerns. Here, the characterization of PM and COat seven subway stations with different forms of platform doors in China are studied. The results show that PM concentrations at platforms are higher than those at halls, followed by the outside. COconcentrations at platforms are remarkably correlated linearly with passenger number. Subsequently, impacts of piston effect on PM and COconcentrations at platforms are assessed. The maximum PMand PMconcentrations with half-height platform bailout doors (HPBD) are increased by 20 % and 36 % respectively when the train enters the station, which are higher than those with platform screen doors (PSD). COconcentrations are decreased by 1.8 % and 4.6 % under the influence of piston effect at platforms with PSD and HPBD, respectively. Compared with coarse particles (larger than 2.5 µm and <10 µm), fine particles (PM) account for larger mass fraction in total particles (38.22 %-62.57 % at all stations), especially at platforms with PSD. The composition and source apportionment of PMreveal that Fe is the most abundant element and six pollution sources are identified at all stations. Among them, the indoor source contributes the most to PMat the station with HPBD. Regardless of the form of platform doors, wheel-rail wear is the largest source of PMinside each station. The above results are expected to provide refer
Abstract
With the vigorous development of subway systems, particulate matter (PM) and COin subway stations is raising increasing concerns. Here, the characterization of PM and COat seven subway stations with different forms of platform doors in China are studied. The results show that PM concentrations at platforms are higher than those at halls, followed by the outside. COconcentrations at platforms are remarkably correlated linearly with passenger number. Subsequently, impacts of piston effect on PM and COconcentrations at platforms are assessed. The maximum PMand PMconcentrations with half-height platform bailout doors (HPBD) are increased by 20 % and 36 % respectively when the train enters the station, which are higher than those with platform screen doors (PSD). COconcentrations are decreased by 1.8 % and 4.6 % under the influence of piston effect at platforms with PSD and HPBD, respectively. Compared with coarse particles (larger than 2.5 µm and <10 µm), fine particles (PM) account for larger mass fraction in total particles (38.22 %-62.57 % at all stations), especially at platforms with PSD. The composition and source apportionment of PMreveal that Fe is the most abundant element and six pollution sources are identified at all stations. Among them, the indoor source contributes the most to PMat the station with HPBD. Regardless of the form of platform doors, wheel-rail wear is the largest source of PMinside each station. The above results are expected to provide reference for the PM control to achieve a healthier underground environment.