Decrease of atmospheric deposition of heavy metals in an urban area from 1994 to 2002 (Paris, France).

Total atmospheric deposition, i.e. both wet and dry ones, was sampled during three different sampling periods between 1994 and 2002. The aim of this study is to determine the temporal variation of the atmospheric deposition fluxes of four heavy metals (Cd, Cu, Pb and Zn) in an urban area (Paris region, France). The global pattern shows a decrease of the fluxes for most of elements during this period. Indeed, the atmospheric deposition fluxes measured in 2001-2002 were lower than those measured during the 1994-1997 period by factors reaching 16, 2.5, 4 and 7.5 at Créteil and 7, 1, 6 and 4.5 at Chatou for Cd, Cu, Pb and Zn, respectively. At the Paris site, the decreasing factors were 2.5 and 3 for Cd and Pb, respectively while Cu and Zn fluxes were nearly similar during the whole studied period.