Abstract
Total suspended particulates (TSP) in ambient air of three sites representing a gradient transect of urbanization along the western coast of Saudi Arabia were collected and their heavy metal contents were analyzed. The sampling was conducted at three sites simultaneously between 16 June to 7 July 2013, 17 September to 1 October 2013 (summer), and 23 December 2013 to 30 January 2014 (winter). The concentration of TSP was very high in ambient air of the two northern sites, ranging between 73 and 883 mu g m(-3) in the far northern site (Rayes, industrial) which is located south to Yanbu industrial city, and it was between 64 and 251 mu g m(-3) in the other site (Rabegh, urban). The southern site (Abhur, residential) showed relatively lower levels of TSP (ranging between 54 and 339 mu g m(-3)). TSPs were also analyzed for 11 heavy metals (Al, Ca, Cu, Mg, Fe, Mn, Zn, Ni, Cr, K, and V) using x-ray fluorescence (XRF) spectrometry. The Fe, Km and Zn concentrations were higher than other elements and they differed significantly among the studied areas. The present study showed that the concentrations of measured elements decreased in the order of industrial > urban > residential.