The application of measurement science to environmental analytical chemistry for air quality studies

Abstract

Preface: Despite improvements in air quality over recent decades, the air we breathe still contains a variety of pollutants at levels that are harmful to human health and environmental sustainability. In particular, air pollution remains a serious problem in highly industrialised and developing countries. In developed countries pollutants such as particulates with their varying chemical compositions, and mercury vapour have emerged as more recent threats to air quality. As a result of these threats a number of international protocols, national and continental legislations is in place to limit the emissions of pollutants from various processes and their eventual concentration in ambient air. Many countries have therefore established air quality monitoring networks to measure the exposure of their populations to harmful substances in air and to assess compliance with relevant legislation and the effectiveness of abatement policies. Furthermore as the global nature and long range transport of pollutants such as mercury vapour is increasingly recognised, the case for international cooperation becomes even more pressing. In this context the requirement for a robust measurement science infrastructure becomes even more important in order to: Ensure measurement methods are appropriate and properly validated; Ensure measurement results are properly traceable to the SI system of units; Ensure the quality of the very large data sets produced by air quality studies. In particular it is clear that measurement science has a role to play in establishing SI traceability of measurement values in order to ensure that air quality data are: Comparable across measurement locations; Stable with reference to a fixed point, so trends over time may be properly gauged; Coherent, so that results made with different measurement methods are comparable. These requirements are not currently in place universally, and are especially lacking for emerging pollutants and such measurands as the chemical composition of particles and for mercury vapour. Therefore relevant stakeholders, often through government (UK Departments such as BIS and Defra) but also via other NGOs, UK Research Councils and industry, have funded work to address these deficiencies and put in place a measurement research infrastructure to underpin these scientific endeavours. The output of such research undertaken by the candidate forms the basis of this DSc submission. Following the award of BSc and PhD degrees from Imperial College the candidate, Dr Richard J. C. Brown, joined the National Physical Laboratory (NPL) in Teddington in 2000 and has since worked on a variety of analytical chemistry problems such as pH metrology, electroanalytical chemistry, surface enhanced Raman spectroscopy, low reflectance surfaces (resulting in the much-publicised ‘NPL Super Black’) and complex data analysis techniques – making significant contributions to each. However his most important and substantial contributions over the last decade have focussed on the application of measurement science principles to environmental analytical chemistry for air quality studies. The candidate has published over 110 peer-reviewed papers during this period (not including refereed conference proceedings). He is NPL’s most prolific author of peer-reviewed papers over the last decade. He has also published over 55 non-peer reviewed works (including conference proceedings, NPL reports, and European and International Page 6 of 20 documentary standards) and has been a co-author on 8 European standards for air quality measurement which are now adopted across the European Union. This submission concentrates on the 21 most significant peer-reviewed publications over this period of time relating to the overarching theme of the application of measurement science to environmental analytical chemistry for air quality studies. The candidate’s role in all cases has been to lead the scientific research and the publication of results, lead authoring the majority of the papers. All the papers presented in this portfolio have been led and published by the candidate’s group either exclusively or with minor contributions from collaborators. The experimentally intensive nature of the work means that in most cases this has been delivered by NPL colleagues under the candidate’s direction and supervision. External contributions are highlighted in the relevant text. The candidate’s work in this area has already received substantial recognition via the Royal Society of Chemistry’s 34th SAC Silver Medal and the 2008 CITAC (Cooperation on International Traceability in Analytical Chemistry) award for the “Most Important Paper on Metrology in Chemistry”. Furthermore, the recent International Benchmarking of NPL’s science (similar to the RAE for universities) overseen by the Royal Society / Royal Academy of Engineering Panel which ensures the quality of NPL’s output, rated Dr Brown’s work as “Internationally Leading” (the top category) for both “Science Quality” and “Impact”. The candidate has also won numerous internal NPL awards for the quality of his work – a considerable achievement when this work is being compared across the whole of NPL’s output, most of which is physics-based. The 21 publications forming this submission are grouped according to sub-area, of which three are considered: ‘Mercury vapour measurement in ambient air’, ‘The chemical composition of particulate matter in ambient air’, and ‘Novel measurement and data analysis techniques’. (Publications considered particularly significant are marked: , next to the publication’s title.) All of these publications are peer-reviewed, and none of these papers has been used for the purpose of obtaining any other degree. For completeness the candidate’s full peer-reviewed publications list appears in the Annex to this submission following the reprints of the papers submitted for consideration. This provides access to other publications in the environmental analytical chemistry area not offered for examination here, and additionally gives an overview of the candidate’s simultaneous contributions to other scientific fields