Lead Research Organisation: London Sch of Hygiene and Trop Medicine
Department Name: Public Health and Policy


While it has been recognised for some time that small particles from vehicle exhausts and other traffic related pollutants cause a range of health effects, policy within the UK and Europe has not directly targeted these. Emissions from vehicles and ambient air itself are regulated in terms of total particles, with no specific targeting of one component or another. While this is clearly prudent in that it potentially drives reductions in all types of particles, it is also inefficient as it is likely that some particles (or particle components) are more toxic than others. This project seeks to elucidate the more toxic components of the pollution mix in London, with particular emphasis on traffic generated particles. If successful this will inform a more focussed and more efficient policy process for regulating vehicle emissions and ambient air quality. As well as regulating vehicle emissions and ambient air, policy makers - particularly at local and regional government level-can influence air pollution impacts through traffic management and wider planning decisions. Here the project will provide better information on spatial and temporal exposures and their relation to adverse impacts of air quality. This dynamic exposure information will be a major step forward in assessing the scope for more focussed traffic and infrastructure planning and management in London, with possible applications elsewhere in the UK. Even though there is a substantial literature confirming the impact of traffic pollution on health there are still substantial gaps. There is very strong evidence that exposure to traffic pollution causes asthma exacerbations in children and reasonably strong evidence that it may cause other health effects including the onset of childhood asthma, non asthma respiratory symptoms, impaired lung function, total and cardiovascular mortality and cardiovascular morbidity. In this project we will undertake a number of new investigations to examine the relationship between chronic exposure to traffic pollution and health. These will include studies of mothers in pregnancy right through to senior citizens. These innovate studies will include health outcomes rarely if ever available for investigation of air pollution effects (e.g. primary care data, child cardiovascular risk factors). The use of exposure metrics on a fine spatial scale that are in routine use for policy in London will enable exposure response relationships to be used for quantifying policy options in terms of health impact. Further this will enable us to evaluate the health impact of trends in exposure to traffic related air pollution, most specifically the Low Emission Zone for London (LEZ).
Description The relationship between neighborhood-level air pollution from traffic sources and hospital admissions and mortality in London is complex. This partly has to do with areas with low deprivation having high air pollution levels. We observed a link between road traffic noise at the neighborhood area and all-cause mortality in London. There was also an association between noise and hospital admission for stroke, particularly among the elderly. These findings require replication using study designs that follow individuals, rather than neighborhoods. Higher air pollution from traffic and other sources was linked with shorter life expectancy among survivors of heart attack in London. Road traffic noise also appeared to be associated with life expectancy independent of air pollution. There are important differences in the socioeconomic patterning of modelled personal exposure to traffic related air pollution compared to exposure estimated at residence. Travel duration and mode are important factors influencing the socioeconomic patterning of personal exposure.
Exploitation Route Our results linking road traffic noise and all cause mortality are the first published on this relationship. Although these results require replication in other populations and using other study designs, this estimate is being used in Health Impact Assessments in other cities (e.g. Barcelona) to estimate the mortality burden from traffic noise. The link between road traffic noise with mortality strengthens the already strong health-based argument for city and urban planners to prioritize active modes of transport over motor vehicles.
Sectors Communities and Social Services/Policy,Energy,Environment,Healthcare,Transport

Description Our estimates linking road traffic noise and all cause mortality are being used in Health Impact Assessment to inform urban policy. The results suggest the mortality burden from road traffic noise can be as large as that of air pollution. The findings liking road traffic noise and mortality received wide, global media coverage in more than 570 outlets including the Washington Post, BBC News, Times of India, and New York Times (Well blog). Dr. Anna Hansell (co-author) gave broadcase interviews on BBC London TV News, BBC London Radio, and BBC World TV News. The journal was published in a high profile clinical cardiovascular journal. This coverage likely raised awareness of the health risks associated with noise among clinical healthcare professionals and the general public.
Sector Environment,Transport
Impact Types Societal,Policy & public services

Description Whitehall II Study 
Organisation University College London
Department Research Department of Epidemiology and Public Health
Country United Kingdom 
Sector Academic/University 
PI Contribution We contributed environmental data generated through the project to the ongoing cohort database for participants resident in Greater London.
Collaborator Contribution They made the data available for the research and provided expertise on the population in general and specific health outcomes (e.g. cognitive function).
Impact The main outputs are publications using the Whitehall II cohort data reported in publications.
Start Year 2009