ATMOSPHERIC LEAD POLLUTION IN AN URBAN AREA BRISBANE, AUSTRALIA

The lead pollution levels recorded in Brisbane at six sites for 1979-91 have been analysed to identify seasonal variations, temporal change and the statistical characteristics of the data sets. The seasonal variations of lead levels from winter to summer are very significant; also the spatial correlations between the lead levels at different sites are generally strong, except for the one site near a busy road (Woolloongabba). The lead levels have decreased markedly since year 1986, probably due to the introduction of unleaded petrol fuelled vehicles at that time. Since then, the violations of lead standard have also dramatically decreased. The log-normal distribution was found to be the most preferred statistical distributions for all the lead data sets, except the Woolloongabba site, for which a normal distribution is preferred; this means that lead levels are more probably high near busy roads. The mean and variance of the lead data at all sites apart from Woolloongabba were able to be predicted to a reasonable degree of accuracy by the ATDL dispersion model. The Woolloongabba data clearly need accurate models for near roadway conditions using on-site meteorological data.