Atmospheric deposit for contaminants in Palmas de Gran Canaria. Metal elements

Abstract

Atmospheric deposition of metallic elements was measured, using a conventional dry collector, from May 1993 to May 1995 at four sites on Las Palmas G.C. Analytical method was Absorption Atomic Spectroscopy. Averaging results from four sites, the following deposition rates were obtained for Las Palmas G.C. in mu g/m(2) . d: Na 1.21 . 104; K 1.24 . 10(3); Ca 1.01 . 10(4); Mg 2.88 . 10(3); Zn 3.2 . 10(2); Fe 2.32 . 10(3); Cu 9 . 10(2), Ni 9.00; Pb 1.4 . 10(2); Cd 1.19. For most elements, dry deposition velocities (cm/s) were estimated, obtaining the copper highest values, 17.3 cm/s, while Pb, Ni and K have been the metals with a greater residence time in the atmosphere. The study of enrichment factors indicates that Pb, Cu, Zn and Cd have an anthropogenic origin. The obtained data reveal a clear seasonal behavior of Na while there is no clear seasonal trend to the other metallic elements depositions, especially Pb, Cd and Fe.