Please login first
Alastair C. Lewis  - - - 
Top co-authors
Chunting Michelle Wang

1 shared publications

University of York

Publication Record
Distribution of Articles published per year 
(1970 - 2018)
Total number of journals
published in
Publications See all
Article 1 Read 0 Citations The changing face of urban air pollution. Alastair C Lewis Published: 16 February 2018
PubMed View at PubMed
Article 1 Read 4 Citations Clustering approaches to improve the performance of low cost air pollution sensors Katie R. Smith, Peter M. Edwards, Mathew John Evans, James D... Published: 01 January 2017
Faraday Discussions, doi: 10.1039/C7FD00020K
DOI See at publisher website PubMed View at PubMed
Article 3 Reads 2 Citations Unexpectedly high concentrations of monoterpenes in a study of UK homes Chunting Michelle Wang, Benjamin Barratt, Nicola Carslaw, Ar... Published: 01 January 2017
Environmental Science: Processes & Impacts, doi: 10.1039/C6EM00569A
DOI See at publisher website PubMed View at PubMed
Article 1 Read 1 Citation VOC emission rates over London and South East England obtained by airborne eddy covariance Adam R. Vaughan, James D. Lee, Marvin D. Shaw, Pawel K. Misz... Published: 01 January 2017
Faraday Discussions, doi: 10.1039/C7FD00002B
DOI See at publisher website PubMed View at PubMed ABS Show/hide abstract
Volatile organic compounds (VOCs) originate from a variety of sources, and play an intrinsic role in influencing air quality. Some VOCs, including benzene, are carcinogens and so directly affect human health, while others, such as isoprene, are very reactive in the atmosphere and play an important role in the formation of secondary pollutants such as ozone and particles. Here we report spatially-resolved measurements of the surface-to-atmosphere fluxes of VOCs across London and SE England made in 2013 and 2014. High-frequency 3-D wind velocities and VOC volume mixing ratios (made by proton transfer reaction – mass spectrometry) were obtained from a low-flying aircraft and used to calculate fluxes using the technique of eddy covariance. A footprint model was then used to quantify the flux contribution from the ground surface at spatial resolution of 100 m, averaged to 1 km. Measured fluxes of benzene over Greater London showed positive agreement with the UK’s National Atmospheric Emissions Inventory, with the highest fluxes originating from central London. Comparison of MTBE and toluene fluxes suggest that petroleum evaporation is an important emission source of toluene in central London. Outside London, increased isoprene emissions were observed over wooded areas, at rates greater than those predicted by a UK regional application of the European Monitoring and Evaluation Programme model (EMEP4UK). This work demonstrates the applicability of the airborne eddy covariance method to the determination of anthropogenic and biogenic VOC fluxes and the possibility of validating emission inventories through measurements.
Article 0 Reads 18 Citations Evaluating the performance of low cost chemical sensors for air pollution research Alastair C. Lewis, James D. Lee, Peter M. Edwards, Marvin D.... Published: 01 January 2016
Faraday Discussions, doi: 10.1039/C5FD00201J
DOI See at publisher website PubMed View at PubMed
Article 1 Read 1 Citation Updated ozone absorption cross section will reduce air quality compliance E. D. Sofen, M. J. Evans, Alastair Lewis, Eric Sofen Published: 10 December 2015
Atmospheric Chemistry and Physics Discussions, doi: 10.5194/acp-15-13627-2015
DOI See at publisher website ABS Show/hide abstract
Photometric ozone measurements rely upon an accurate value of the ozone absorption cross section at 253.65 nm. This has recently been re-evaluated by Viallon et al. (2015) as 1.8 % smaller than the accepted value (Hearn, 1961) used for the preceding 50 years. Thus, ozone measurements that applied the older cross section systematically underestimate the amount of ozone in air. We correct the reported historical surface data from North America and Europe and find that this modest change in cross section has a significant impact on the number of locations that are out of compliance with air quality regulations if the air quality standards remain the same. We find 18, 23, and 20 % increases in the number of sites that are out of compliance with current US, Canadian, and European ozone air quality health standards for the year 2012. Should the new cross-section value be applied, it would impact attainment of air quality standards and compliance with relevant clean air acts, unless the air quality target values themselves were also changed proportionately. We draw attention to how a small change in gas metrology has a global impact on attainment and compliance with legal air quality standards. We suggest that further laboratory work to evaluate the new cross section is needed and suggest three possible technical and policy responses should the new cross section be adopted.