The significance of traffic related pollution levels and its dilution associated with altitude.

This paper identifies the significance of pollution at five sites amongst the worst on the British mainland hence indicative of other polluted areas within Europe. Three sites are located in London and one each in Birmingham and Cardiff. The pollutants examined are NO2, SO2, O3 and PM10. Newly proposed DOE figures defining poor air quality have been used to re-examine the frequency of excess pollution episodes between 1992-1995. The results identify the most appropriate periods for natural ventilation of offices in urban areas in terms of the hour in a day and time of year. Preliminary in-situ experiments also demonstrate that both PM10 and NO2 concentrations decrease with increasing height from a busy road, and that this could be a useful strategy for reducing the impact of contaminants derived from vehicle emissions.