Short-term and spatial variation of selected metals in the atmosphere of Nitero ´i City, Brazil Silvia M. Sella a, * , Annibal D. Pereira Netto a , Emmanoel Vieira da Silva Filho b , Martha T. Arau ´jo c a Department of Analytical Chemistry, Federal Fluminense University, Outeiro de Sa ˜o Joa ˜o Batista s/no Centro, Nitero ´i 24020-150, RJ, Brazil b Department of Geochemistry, Federal Fluminense University, Outeiro de Sa ˜o Joa ˜o Batista s/no Centro, Nitero ´i 24020-150, RJ, Brazil c Department of Physical Chemistry, Federal Fluminense University, Outeiro de Sa ˜o Joa ˜o Batista s/no Centro, Nitero ´i 24020-150, RJ, Brazil Accepted 11 March 2004 Available online 10 May 2004 Abstract In this work, the atmospheric concentration of selected trace elements (Cd, Fe, Mn, Pb, V and Zn) was determined in total suspended material (TSP) from three sampling sites located at Nitero ´i, an urban medium city of Rio de Janeiro, Brazil. TSP samples were collected with a high volume air sampler and glass fibber filters. The determinations of Cd, Pb and Zn were performed by ICP-AES while V was determined by ETA-AAS and Fe and Mn were measured by FAAS. Among all elements, Fe showed the highest concentrations (0.5–12.5 Ag/m 3 ) during the study but the concentrations of all elements varied along the week. The maximum levels of TSP, Fe, Mn, Cd and V were observed on Wednesday which was characterised by the highest winds frequency with higher speeds coming from the North quadrant, mainly from the Northeast direction. Enrichment factors showed that Cd, Pb and Zn are enriched in all sites suggesting that anthropogenic sources play important roles for those elements. Statistical analysis has been carried out to evaluate the effect of meteorological parameters and characterisation of sampling sites. D 2004 Elsevier B.V. All rights reserved. Keywords: TSP; Heavy metals; Atmospheric pollution; Environmental pollution 1. Introduction In urban areas, anthropogenic sources release high quan- tities of several elements in the atmosphere, soil and aquatic ecosystems exceeding natural emissions levels [1] and leading to increased levels of several elements in those environmental compartments. The main inputs for many elements in the atmosphere are related to particle emission process. Regarding trace metals (Pb, Cd, Zn, etc.), anthropogenic sources play more signif- icant roles than natural sources, such as continental dust, salt spray and biogenic particles [2,3]. For most elements, (Fe, Mn, Al, etc.), soil and dust resuspension represent their major (natural) sources. The presence of trace metals in atmospheric particulate matter has been associated with respiratory diseases due to inhalation of small particles (V2.5 Am) that may be absorbed by the lung [4]. Moreover, particulate matter can affect climate and vegetation and also reduce visibility. Atmospheric metal concentrations shows spatial varia- tion since they are dependent of the distances to the sources and of the relative importance of local sources. Seasonal variation has been observed in atmospheric metal concen- trations in temperate or cold climates [5], but their levels are also influenced by meteorological variables such as wind speed and direction. Short-term differences of atmospheric metal concentrations have been observed in a day by day or even in hour-by-hour basis [6]. Rio de Janeiro State is located in the Southwest of Brazil with an area of 43,305 km 2 and 13,064.296 inhabitants and the main economic activities include: industries, agriculture, fishing, mining and tourism. The climate is tropical, hot and wet, with annual precipitation up to 2 m and lacking of a well-defined dry season. Average minimum and maximum temperatures range from 20 to 27 jC. Nitero ´i City is located in the margins of Guanabara Bay near Rio de Janeiro City, capital of the Rio de Janeiro State (the second biggest city of 0026-265X/$ - see front matter D 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.microc.2004.03.015 * Corresponding author. Fax: +55-21-26292143. E-mail address: gqasela@vm.uff.br (S.M. Sella). www.elsevier.com/locate/microc Microchemical Journal 78 (2004) 85 – 90