Size distribution of metals in urban aerosols in Seville (Spain)

The size distribution of metals in aerosols has been studied in 12 areas of the city of Seville. Urban particles were collected with a high-volume sam pling system equipped with a cascade impactor, which effectively separates the particulate matter into six-size ranges. Forty-one samples were collect ed in spring 1996. Each filter was extracted with a mixture of nitric and p ercloric acids. The acid solutions of the samples were analysed in six-part icle fractions by inductively coupled plasma atomic emission spectrometry ( ICP-AES). The impactor stage fractionation of particles shows a typical bim odal distributions, one corresponding to the fine mode below 1 mum (55%), a nd the other to the coarse mode around 10 mum (32%). With regard to the siz e distribution of metals, we concluded that potentially toxic metals, such as nickel, lead and cadmium are mainly accumulated in the smaller particles , with percentages of 72.6, 69.4 and 63.8 %, respectively. Lead have a conc entration of 63.7 ng m(-3), more than copper and manganese (26.7 and 16.5 n g m(-3)) and above all more than nickel, cobalt and cadmium (1.97, 0.54 and 0.32 ng m(-3)). (C) 2001 Elsevier Science Ltd. All rights reserved.