Air quality in London London Air Quality Network Report 14 2006-7 Main contact London Air Quality Network Environmental Research Group King’s College London Fourth Floor Franklin-Wilkins Building 150 Stamford Street London SE1 9NH 020 7848 4019 [email protected] Written by Gary Fuller, Louise Meston, David Green, Emily Westmoreland and Frank Kelly. Introduction Contents The measurements detailed in this report result from a 2 team effort, undertaken by staff who are dedicated and Foreword committed to their work. 4 Summary The Environmental Research Group 6 Director of the Environmental Air quality modelling Introduction Research Group Sean Beevers* Professor Frank Kelly David Dajnak 7 Stephen Hedley 1. Recent trends in London’s Air quality monitoring Nutthida Kitwiroon air pollution Jon Alexander Hrishi Mittal Timothy Baker Cathryn Tonne 29 Ben Barratt Emily Westmoreland 2. The volatile correction model Hima Chouhan Finance Gary Fuller* 31 David Green Maria Lavender* 3. The London Atmospheric Andrew Grieve Computing Emissions Inventory Paul Johnson Daniel Marsh Robert Hepburn* Louise Meston Sam Hope-Evans 34 Karin Nilsdotter Ian Troughton 4. Oxidative potential – Ellie Norris a new measurement of Administration Max Priestman particle health effects? Ana Rowan Adina Beck Anja Tremper Justin Holder 36 Emissions Valentina Lotti* References Lung Biology Stephen Hedley* Stephen Inch Chrissie Dunster 38 Appendix 1: Network Ian Mudway changes 2006-7 *Suggested first point of contact within each team. 44 Appendix 2: Sites 50 Appendix 3: Detailed results 2006 70 Appendix 4: Detailed results 2007 www.londonair.org.uk 1 Foreword Professor Frank Kelly, Director of the Environmental Research Group (ERG) elcome to the fourteenth annual report of the Given that London is still having trouble meeting these London Air Quality Network (LAQN). This insufficiently stringent PM targets, there is clearly no Wpublication provides a strategic overview of room for complacency and much to be achieved. air pollution across London during 2006 and 2007 and as During the last 12 months ERG staff, together with such, can act as a stand-alone document for comparison colleagues from St George’s, and the London School of with other cities, as well as part of the ongoing annual air Hygiene & Tropical Medicine, completed work on pollution record for London. The report provides a vital assessing the impact of the Congestion Charging Scheme resource for anyone interested in air quality, especially (CCS) in London. The work undertaken by this those who are working at local and national levels, and for interdisciplinary group of epidemiologists, toxicologists individuals developing policies to help reduce the level of and air pollution scientists into air quality and health air pollution in the UK. impacts of Europe’s largest experiment in urban traffic The information in this report originates not only from management continues to attract international attention. the LAQN, managed by the Air Quality Monitoring The final report, to be published shortly, will confirm the group and led by Gary Fuller at King’s College London, difficulty in influencing urban air quality in the absence of but is enhanced by input from the ERG’s Air Quality city–wide regulatory schemes. Management Group. The combined and complementary The same team of investigators also continued to expertise of individuals in these groups is also highlighted examine the impact of the London-wide Low Emission in the LAQN website www.londonair.org.uk. The latter Zone (LEZ) that was introduced in February 2008. contains summaries of air pollution across the LAQN, and Given the worldwide worries about diesel emissions and a number of tools to allow the user to analyse and plot public health, and especially that of children’s, the LEZ data. The site represents an excellent resource for all those certainly has the potential to provide benefit to Londoners interested in air pollution. and those who work in and visit the capital. In 2006-7 London, in parallel with many other large cities around the world, continued to have difficulties in controlling air quality and as a consequence, experienced high levels of pollution. Traffic-related air pollution remains one of the most pressing problems in urban areas, contributing most to NOx and PM emissions. Moreover, evidence of adverse health effects resulting from these pollutants continues to emerge at an alarming rate. Human exposure to air pollutants in densely populated urban areas is thus high, and improvement in air quality is therefore imperative. In this respect, the recently published Royal Society report on ‘Ground-level Ozone in the 21st Century’ is a stark reminder that climate change controls will need to be carefully formulated to attain the maximum benefit from both a climate change and air quality perspective. The health consequences of increasing background O3 concentrations in the UK and across Europe being possibly worse than existing PM impacts. The past 12 months also saw the publication of the long awaited updated EU air quality directive. Unfortunately, this has only caused dismay amongst health researchers as it is, in essence, a relaxation in relation to previous PM10 Limit Values. The new PM2.5 Limit Value has been set at the upper end of exposure response curves from the major epidemiological studies, and hence not sufficiently protective of human health. 2 www.londonair.org.uk IMAGE: FRANCISBOOTH.COM IMAGE: www.londonair.org.uk 3 Summary ir pollution concentrations in London continued Background NO2 concentrations declined until 2002 to exceed UK Air Quality Strategy Objective but have been relatively stable since. Importantly, the (AQS) and EU Limit Values during 2006 and annual mean AQS Objective and EU Limit Value of 40 A -3 2007. Progress towards the attainment of these legislated μg m has been attained at background sites in outer values varies according to pollutant; successes in the London only and this concentration has been consistently control of CO and SO2 concentrations contrast with the exceeded at background sites in inner London and at less successful control of NO2, PM10 and O3. roadside sites throughout London. During 2006 and Annual mean concentrations of CO in London have 2007, the annual mean objective was exceeded at almost been successfully decreased by 56% from the end of all roadside sites and it was also exceeded at background 1996 to 2007. The EU Limit Value has been attained sites across inner and parts of east and west London. The in London since 2000. Carbon monoxide emissions mean concentration of NO2 at roadside sites in inner nevertheless remain important in regional O3 formation. London exceeded the annual mean AQS Objective and Similar decreases have also been measured in annual EU Limit Value by a factor of more than two during 2006 mean SO2 concentrations and AQS objectives for and 2007. This has important implications for the UK SO2 have not been exceeded in London since 1998. government’s intention to seek a five year extension to the However, SO2 pollution incidents do still occur in 2010 date for attainment of the EU Limit Value. London; a notable incident affected west London during NO2 concentrations at roadside sites do not show a the July 2006 ‘heat wave’. The relative importance of SO2 clear overall change since 1997, despite the reduction in may increase in the future if new World Health NOX concentrations at these sites. Further examination of Organisation (WHO) Guidelines are adopted within the roadside NO2 concentrations on a site by site basis shows UK and Europe. a range of changes from little overall change to increases of 4 www.londonair.org.uk over 30% at some sites, including Marylebone Road. This localised nature of particle number concentrations and the increase in roadside NO2 concentrations was caused by a additional toxicity of roadside PM10, London-wide change in the proportion of NO2 directly emitted in measures to abate PM10 may be effective in reducing both vehicle exhausts. There is clearly a need for additional mass concentration and health effects of PM10 in London. measures to control concentrations of this pollutant. The Greater London Authority and Transport for During December 2007 London experienced its most London funded emissions inventory form a core upon severe NO2 episode in ten years. This appears to have which such abatement scenarios can be assessed. The been due to both meteorological conditions and changes transport part of this inventory has been recently updated in NO2 primary emissions. for the 2006 base year. Mean PM10 concentrations in London decreased Annual mean concentration of O3 increased by 37% during the late 1990’s but show a steady slow increase between the end of 1996 and 2007. This increase is since this time at a mean rate of around 0.4% per year. thought to be due to changes in global concentrations and Although the EU Limit Value has been attained at also London-wide abatement of NOX. O3 concentrations background sites since the late 1990’s the EU Limit Value during the 2006 ‘heat wave’ were the greatest since 2003. is regularly breached alongside the busiest parts of The peak concentrations during these episodes have London’s trunk road network and close to waste decreased due to European-wide emissions control; peak management sites. Use of the new volatile correction concentrations during 2003 and 2006 were less than those model (VCM), instead of the current 1.3 factor, to experienced in London during the 1980s and 1990s and ‘correct’ TEOM measurements to gravimetric equivalent were less than around half of the concentration measured will decrease the number of locations exceeding the EU during the 1976 ‘heat wave’. Limit Value during 2006 and 2007 but breaches of the Limit Value remain around waste sites and the busiest sections of the trunk road network.