Granulometric and magnetic properties of deposited particles in the Beijing subway and the implications for air quality management
Granulometric and magnetic properties of deposited particles in the Beijing subway and the implications for air quality management
The subway system is an important traffic facility in Beijing and its internal air quality is an environmental issue that could potentially affect millions of people every day. Due to the intrinsic nature of rail abrasion in subway tunnels, iron-containing particles can be generated and become suspended in the subway environment. While some studies (e.g. Li et al., 2006) have monitored the in-train levels of PM2.5 (particles < 2.5 ?m), there is a lack of systematic assessment of the concentration and characteristics of iron-containing particles in the Beijing subway system. Here we report results of a study on the granulometric and magnetic properties of deposited particle samples collected at different localities of the Beijing subway system. Our results show that the subway samples are characterized by the presence of fine particles. Volume proportions of 6.1 ± 1.3% for particles < 2.5 ?m and 27.5 ± 6.1% for particles < 10 ?m are found in the bulk subway samples. These samples exhibit a strong magnetic signal, which is approximately two orders of magnitude higher than that in naturally deposited particles collected in Beijing. Fine grained ferromagnetic and ferrimagnetic minerals (e.g. iron and magnetite, respectively) are identified from mineral magnetic measurements and scanning electric microscopy. The samples collected from the Beijing stations with platform screen doors are found to be magnetically stronger and finer than those without them, suggesting that platform screen doors have failed to block the fine iron-containing particles released from the rail tunnel. Given the potential health consequences of fine suspended iron-containing particles, our results have important implications for air quality management in the Beijing subway system.
1059-1068
Cui, G.
b7fc865d-feb3-412b-b34f-fd6dd6dae0de
Zhou, L.
56fb9a25-55a9-4b5b-be3a-6cd2c03ff471
Dearing, J.
dff37300-b8a6-4406-ad84-89aa01de03d7
15 October 2016
Cui, G.
b7fc865d-feb3-412b-b34f-fd6dd6dae0de
Zhou, L.
56fb9a25-55a9-4b5b-be3a-6cd2c03ff471
Dearing, J.
dff37300-b8a6-4406-ad84-89aa01de03d7
Cui, G., Zhou, L. and Dearing, J.
(2016)
Granulometric and magnetic properties of deposited particles in the Beijing subway and the implications for air quality management.
Science of the Total Environment, 568, .
(doi:10.1016/j.scitotenv.2016.06.154).
Abstract
The subway system is an important traffic facility in Beijing and its internal air quality is an environmental issue that could potentially affect millions of people every day. Due to the intrinsic nature of rail abrasion in subway tunnels, iron-containing particles can be generated and become suspended in the subway environment. While some studies (e.g. Li et al., 2006) have monitored the in-train levels of PM2.5 (particles < 2.5 ?m), there is a lack of systematic assessment of the concentration and characteristics of iron-containing particles in the Beijing subway system. Here we report results of a study on the granulometric and magnetic properties of deposited particle samples collected at different localities of the Beijing subway system. Our results show that the subway samples are characterized by the presence of fine particles. Volume proportions of 6.1 ± 1.3% for particles < 2.5 ?m and 27.5 ± 6.1% for particles < 10 ?m are found in the bulk subway samples. These samples exhibit a strong magnetic signal, which is approximately two orders of magnitude higher than that in naturally deposited particles collected in Beijing. Fine grained ferromagnetic and ferrimagnetic minerals (e.g. iron and magnetite, respectively) are identified from mineral magnetic measurements and scanning electric microscopy. The samples collected from the Beijing stations with platform screen doors are found to be magnetically stronger and finer than those without them, suggesting that platform screen doors have failed to block the fine iron-containing particles released from the rail tunnel. Given the potential health consequences of fine suspended iron-containing particles, our results have important implications for air quality management in the Beijing subway system.
Text
STOTEN-S-16-01383_BJ subway_final.pdf
- Accepted Manuscript
More information
Accepted/In Press date: 20 June 2016
e-pub ahead of print date: 30 June 2016
Published date: 15 October 2016
Organisations:
Palaeoenvironment Laboratory (PLUS)
Identifiers
Local EPrints ID: 399985
URI: http://eprints.soton.ac.uk/id/eprint/399985
ISSN: 0048-9697
PURE UUID: 8018c1a2-acb2-4381-bd78-1f22f4199122
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Date deposited: 06 Sep 2016 10:57
Last modified: 15 Mar 2024 05:52
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Author:
G. Cui
Author:
L. Zhou
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