URBAN AIR-POLLUTION

In this review the scale of urban air is assessed and the sources and health effects of the main urban pollutants are identified. Methods of monitoring, used to determine compliance with UK air quality standards are reviewed, and important sampling criteria are determined. Measurements of spatial spatial and temporal variations in pollutant concentrations are described using both single-site continuous analysers and time-integrated multi-site samplers. The declines in concentration of the 'traditional' pollutants, sulphur dioxide (SO2) and smoke, as well as in airborne lead are compared to the increasing emissions of traffic-related pollutants, carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O-3) and fine particulates. For each of these pollutants appropriate monitoring methods are described. A case study of Cambridge air quality data illustrates the changing nature of urban air pollution. Finally, long-term air quality monitoring programmes are seen to have an important role in determining the effectiveness of future vehicle emission controls and traffic management schemes for urban centres.