Characteristics of fine and ultrafine aerosols in the London underground.
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Published version
Author(s)
Type
Journal Article
Abstract
Underground railway systems are recognised spaces of increased personal pollution exposure. We studied the number-size distribution and physico-chemical characteristics of ultrafine (PM0.1), fine (PM0.1-2.5) and coarse (PM2.5-10) particles collected on a London underground platform. Particle number concentrations gradually increased throughout the day, with a maximum concentration between 18:00 h and 21:00 h (local time). There was a maximum decrease in mass for the PM2.5, PM2.5-10 and black carbon of 3.9, 4.5 and ~ 21-times, respectively, between operable (OpHrs) and non-operable (N-OpHrs) hours. Average PM10 (52 μg m-3) and PM2.5 (34 μg m-3) concentrations over the full data showed levels above the World Health Organization Air Quality Guidelines. Respiratory deposition doses of particle number and mass concentrations were calculated and found to be two- and four-times higher during OpHrs compared with N-OpHrs, reflecting events such as train arrival/departure during OpHrs. Organic compounds were composed of aromatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) which are known to be harmful to health. Specific ratios of PAHs were identified for underground transport that may reflect an interaction between PAHs and fine particles. Scanning transmission electron microscopy (STEM) chemical maps of fine and ultrafine fractions show they are composed of Fe and O in the form of magnetite and nanosized mixtures of metals including Cr, Al, Ni and Mn. These findings, and the low air change rate (0.17 to 0.46 h-1), highlight the need to improve the ventilation conditions.
Date Issued
2023-02-01
Date Acceptance
2022-10-05
ISSN
0048-9697
Publisher
Elsevier
Journal / Book Title
Science of the Total Environment
Volume
858
Issue
Pt 1
Copyright Statement
© 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Engineering and Physical Sciences Research Council
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/36283528
S0048-9697(22)06414-2
Grant Number
EP/T003189/1
EP/T003189/1
Subjects
Exposure assessment
Metal content
Particle characterisation
Subway station
Underground pollution
Exposure assessment
Metal content
Particle characterisation
Subway station
Underground pollution
Environmental Sciences
Publication Status
Published
Coverage Spatial
Netherlands
Article Number
ARTN 159315
Date Publish Online
2022-10-22