Environmental Research Group
Monitoring » Case Studies
The Effects of the Low Emissions Zone on Pollution and Health
The Environmental Research Group has secured funding from the prestigious Health Effects Institute (HEI) in
the US to carry out a baseline study into the effects of the London Low Emission Zone (LEZ) on pollution and health.
The project brings together researchers from King's College London, London School of Hygiene & Tropical Medicine and
St George's, University of London and staff from Transport for London. This team recently completed a study into the
effects of the London Congestion Charging Scheme on air quality, also funded by the HEI.
The primary aim of the LEZ is to reduce PM10 concentrations across Greater London by targeting the most heavily
polluting diesel vehicles – older Heavy Goods Vehicles (HGVs), buses and coaches. The zone will cover an area of
2644 km2 in which more than 8 million people reside.
Given the magnitude and nature of the proposed LEZ intervention there is good reason to believe that it will lead
to a range of health benefits for London residents. For example, numerous studies have indicated that living
in the vicinity of roads utilised by heavy duty traffic is associated with an increased prevalence of chronic
respiratory symptoms. Moreover, convincing evidence has been found suggesting that children attending schools
close to motorways with high truck traffic experienced more respiratory symptoms than children attending
schools near motorways with low truck traffic counts.
The LEZ baseline study is primarily a data gathering and methodology development study: it has four main objectives:
- To produce model predictions of the effects of the LEZ and to estimate the areas in London that show the greatest change in atmospheric concentration and population exposure.
- To design a comprehensive LEZ impacts monitoring network to maximise the potential for detecting a signal in pollution metrics.
- To Characterise the oxidative properties and water soluble metal content of ambient PM10 and PM2.5 in London prior to the implementation of the LEZ.
- To develop procedures and methodology to extract health information from the primary care network to facilitate future health-based studies.
The final report for the first phase of the project was submitted to the Health Effects Institute in December 2007 and is currently under review. This report will be available for downloading
on this website once has been finalised and released by the funding body.
Research is ongoing with funding from TfL into the effects of the LEZ on air pollution concentrations and toxicity.
It is hoped that further funding will be obtained from the HEI during 2008 to link this research with primary care network data,
with the ultimate aim of detecting an LEZ-related effect on the health of London's population.
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