Recent metal pollution in Agassiz Ice Cap

Metal data for Ph, Zn, Al, Cd, and TI show seasonal variations of high leve ls during the winter-early spring period and low levels during the summer-f all period. In terms of Pb magnitudes and seasonal variations, our data of the late 1980s and early 1999s (unleaded gasoline era) appear compatible wi th those of Murozumi et at. (Murozumi, M.; Chow, T. J.; Patterson, C. C. Ge ochim. Cosmochim. Acta 1969, 33, 1247-1294.) of the 1950s and 1965 (leaded gasoline era). This is probably due to the close proximity and similar elev ation of the two areas (Agassiz Ice Cap, Canadian Arctic and Camp Century, northwest Greenland), which are likely subjected to the same polluted air m asses. Despite the implementation of unleaded gasoline since the early 1970 s, our data show that the Agassiz Ice Cap still received a significant amou nt of lead during the late 1980s and early 1990s; this is in contrast to Su mmit, Greenland, which saw a very drastic decrease of the element during si milar periods. This is because of the different locations and altitudes, as well as different sources, mainly Eurasian for Agassiz versus mainly U.S. for Summit. Lead was determined by laser-induced fluorescence spectrometry via the direct injection of microliter sample sizes. Its fallout flux was e stimated to be 1.2 ng cm(-2) year(-1) The lead concentration in the surface snow appears to follow the order of Agassiz and northwest Greenland > cent ral Greenland > Antarctica.