Imperial College London
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DrDavidGreen

Faculty of Medicine, School of Public Health

Senior Research Fellow
 
 
 
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d.green

 
 
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Location

 

Sir Michael Uren HubWhite City Campus

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Summary

 

Publications

Citation

BibTex format

@article{Muxworthy:2022:10.1016/j.atmosenv.2022.119292,
author = {Muxworthy, A and Lam, C and Green, D and Cowan, A and Maher, B and Gonet, T},
doi = {10.1016/j.atmosenv.2022.119292},
journal = {Atmospheric Environment},
pages = {1--8},
title = {Magnetic characterisation of London’s airborne nanoparticulate matter},
url = {http://dx.doi.org/10.1016/j.atmosenv.2022.119292},
volume = {287},
year = {2022}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Iron-bearing particulate matter produced by vehicle emissions is known to be toxic. To better quantify potential health risks, we have conducted the first magnetic study of a time-series of London's inhalable particulate matter (<10 μm, PM10), captured by three monitoring stations in central London (Marylebone Road, Earl's Court Road and Oxford Street) through 2010 and 2012. We conducted room-temperature analysis on all the samples, and a limited number of samples were analysed at both high and low temperatures. The high-temperature measurements identified magnetite as the dominant magnetic phase. The low-temperature measurements revealed high numbers of nanoparticles, which, assuming magnetite, are in the grain-size range 1–4 nm. It is estimated that as much as ∼40% of the total magnetic signal at 10 K is from particles <4 nm, that are magnetically ‘invisible’ at room-temperature and are being routinely under-estimated in room temperature-based magnetic studies. From the low-temperature measurements, the total concentration of magnetite was estimated at ∼7.5%, significantly higher than previously reported. The room-temperature magnetic data were compared with other pollution data, e.g., NOX and PM10, and meteorological data. Mass-dependent terms like the saturation magnetisation were found to display a strong correlation with NOX and PM10, indicating a common source for these pollutants, i.e., vehicle emissions. Magnetic coercivity measurements, which are independent of abundance, and provide information on grain-size, were consistent across all three sampling localities, again suggesting a major dominant source. Relatively small variations in coercivity were correlated with meteorological events, e.g., temperature and precipitation, suggesting preferential removal of larger airborne grains, i.e., >50 nm.
AU  - Muxworthy,A
AU  - Lam,C
AU  - Green,D
AU  - Cowan,A
AU  - Maher,B
AU  - Gonet,T
DO  - 10.1016/j.atmosenv.2022.119292
EP  - 8
PY  - 2022///
SN  - 1352-2310
SP  - 1
TI  - Magnetic characterisation of London’s airborne nanoparticulate matter
T2  - Atmospheric Environment
UR  - http://dx.doi.org/10.1016/j.atmosenv.2022.119292
UR  - https://www.sciencedirect.com/science/article/pii/S1352231022003570?via%3Dihub
UR  - http://hdl.handle.net/10044/1/98602
VL  - 287
ER  -
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