Application of ¹⁴C analyses to source apportionment of carbonaceous PM_2.5 in the UK

Heal, M.R., Naysmith, P. , Cook, G.T. , Xu, S., Duran, T.R. and Harrison, R.M. (2011) Application of ¹⁴C analyses to source apportionment of carbonaceous PM_2.5 in the UK. Atmospheric Environment, 45(14), pp. 2341-2348. (doi: 10.1016/j.atmosenv.2011.02.029)

Abstract

Determination of the radiocarbon (¹⁴C) content of airborne particulate matter yields insight into the proportion of the carbonaceous material derived from fossil and contemporary carbon sources. Daily samples of PM_2.5 were collected by high-volume sampler at an urban background site in Birmingham, UK, and the fraction of ¹⁴C in both the total carbon, and in the organic and elemental carbon fractions, determined by two-stage combustion to CO₂, graphitisation and quantification by accelerator mass spectrometry. OC and EC content was also determined by Sunset Analyzer. The mean fraction contemporary TC in the PM_2.5 samples was 0.50 (range 0.27–0.66, n = 26). There was no seasonality to the data, but there was a positive trend between fraction contemporary TC and magnitude of SOC/TC ratio and for the high values of these two parameters to be associated with air-mass back trajectories arriving in Birmingham from over land. Using a five-compartment mass balance model on fraction contemporary carbon in OC and EC, the following average source apportionment for the TC in these PM_2.5 samples was derived: 27% fossil EC; 20% fossil OC; 2% biomass EC; 10% biomass OC; and 41% biogenic OC. The latter category will comprise, in addition to BVOC-derived SOC, other non-combustion contemporary carbon sources such as biological particles, vegetative detritus, humic material and tyre wear. The proportion of total PM_2.5 at this location estimated to derive from BVOC-derived secondary organic aerosol was 9–29%. The findings from this work are consistent with those from elsewhere in Europe and support the conclusion of a significant and ubiquitous contribution from non-fossil biogenic sources to the carbon in terrestrial aerosol.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Naysmith, Mr Phillip and Cook, Professor Gordon and Xu, Dr Sheng
• Authors: Heal, M.R., Naysmith, P., Cook, G.T., Xu, S., Duran, T.R., and Harrison, R.M.
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Atmospheric Environment
• Publisher: Elsevier
• ISSN: 1352-2310
• Published Online: 19 February 2011
• Copyright Holders: Copyright © 2011 Elsevier
• First Published: First published in Atmospheric Environment 2011 45 (14):2341-2348)
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher