Azaarenes in the aerosol of an urban atmosphere

The results of an extensive study of 47 azaarenes in the Liverpool urban atmosphere through the period from September 1994 to March 1996 are reported. Total suspended particles and size-fractionated particles were collected by high Volume sampling techniques and cascade impactor sampling techniques. The overall mean Sigma azaarene concentration was 2.80 ng m(-3). The monthly mean Sigma azaarene concentrations show a very strong seasonal Variation in which the maximum concentration occurred in the winter and the minimum in the summer months, with a concentration range of 0.4-7.64 ng m(-3). There are highly significant covariations between the different ring sized group, which suggests that there are similar source strengths and transport mechanisms for these compounds. The particle size distributions indicate that the combustion of fossil fuel is probably the main source of azaarene compounds during the winter. The percentage concentrations of azaarene show that these compounds also tend to associate with larger particles in warm periods and enrich in fine particles in cold weather conditions.