Physicochemical Properties of Indoor Particulate Matter Collected on Subway Platforms in Japan

Abstract

This study was aimed to thoroughly estimate the characteristics of indoor particulate matter (PM) collected on subway platforms by the cooperative approach of semi-bulk and single particle analyses. The size-resolved PM and its number concentration were measured on the platform in a heavily traveled subway station in Fukuoka, Japan. Particle Induced Xray Emission (PIXE) and micro-PIXE techniques were applied to the chemical analyses of semi-bulk and single particle, respectively. There was the close resemblance of timely fluctuation between PM number concentration and train service on the third basement floor (B3F) platform compared to the second basement floor (B2F) and its maximum level was marked in rush hour. Higher number counts in large particles (¤1 μm) and lower number counts in fine particles (⁄1 μm) were shown on the platform compared to an above ground. PM2.5 accounted for 58.2% and 38.2 % of TSP on B3F and on B2F, respectively. The elements that were ranked at high concentration in sizeresolved semi-bulk PM were Fe, Si, Ca, S, and Na. The major elements tending to have more elevated levels on B3F than B2F were Fe (4.4 times), Ca (17.3 times), and Si (46.4 times). Although concentrations were very low, Cr (11.9 ng m -3 on B3F, 2.4 ng m -3 on B2F), Mn (3.4 ng m -3 on B3F, 0.9 ng m -3 on B2F), and Pb (0.6 ng m -3 on B3F, 1.6 ng m -3 on B2F) were detected from PM2.5. Individual PM was nearly all enriched in Fe with Si and Ca. Classifying and source profiling of the individual particles by elemental maps and particle morphology were tried and particles were presumably divided into four groups (i.e., train/rail friction, train-rail sparking, ballast/abrasive, and cement).

Particulate matter concentrations and heavy metal contamination levels in the railway transport system of Sydney, Australia

“…The Fe concentration was almost 20 times greater than the background results suggesting that the railway environment has additional local sources of Fe which need to be carefully considered when estimating the potential human health implications that might result from personal exposure. The substantial presence of Fe has also been reported in other subway studies suggesting that the wear and abrasion processes in the rail lines, wheels and the brake system are the main sources of Fe and other metal substances (Kam et al, 2011b;Ma et al, 2012;Martins et al, 2016;Moreno et al, 2015). Fig.…”

“…Each set of data was subdivided into two groups depending on the measuring level (ground level and underground level). The DustTrak device was carried out at the breathing level of commuters in compliance with recommendations and practices reported in other studies (Gulliver and Briggs, 2004;Ma et al, 2012;Moore and Figliozzi, 2011). To further investigate the effect of the operating levels (ground and underground), an additional sampling campaign was conducted from 22 nd February to 4 th March 2016 at the Town Hall Station (platforms and concourse level) for 30 min at each level to measure PM10.…”

“…DustTrak, TEOM), surrounding metrological conditions and other factors which might significantly affect PM concentrations. Studies have also shown remarkable improvements in reducing PM concentrations after the installation of the platform screen doors (PSDs) which act as a physical barrier to isolate the air quality on the platforms (Kim et al, 2012;Ma et al, 2012;Martins et al, 2015). Table 6 shows the mean concentration values (mg/g) for the twelve metals based on the results of MP-AES analysis of dust samples from the railway platforms and the background samples.…”

A novel approach for the modelling of air quality dynamics in underground railway stations

“…Numerous measurement campaigns and numerical comparisons have been undertaken worldwide, e.g. Strak et al [1] in the Netherlands, Ma et al [2] in Japan, Park et al [3] in Korea or Gomez et al [4] in Mexico City, as they help to understand the mechanisms that create such indoor/outdoor pollutions, with the aim to reduce them. However, these studies mainly measure the pollution levels and provide design or operation recommendations, without a quantitative analysis of the link between train traffic and particulate matter concentration.…”

Properties of Indoor Particles Collected in Japanese Homes

“…But the air inside homes, offices, other buildings, and subway can be more polluted than the air outside (Ma et al, 2012;Salo et al, 2008;Chillrud et al, 2005). Although there is a difference among individuals, human beings spend most of their lifetime in indoor environments, especially house.…”