Meteoric smoke fallout over the Holocene epoch revealed by iridium and platinum in Greenland ice.

An iridium anomaly at the Cretaceous/Tertiary boundary layer has been attributed to an extraterrestrial body that struck the Earth some 65 million years ago. It has been suggested that, during this event, the carrier of iridium was probably a micrometre-sized silicate-enclosed aggregate or the nanophase material of the vaporized impactor. But the fate of platinum-group elements (such as iridium) that regularly enter the atmosphere via ablating meteoroids remains largely unknown.

Short-term variations in the occurrence of heavy metals in Antarctic snow from Coats Land since the 1920s.

Short-term variations in heavy metals concentrations in Antarctic snow have been investigated by analysing 13 metals (Al, V, Cr, Mn, Co, Cu, Zn, Ag, Cd, Ba, Pb, Bi and U) in a series of ultraclean samples collected from two snow pits in Coats Land in the Atlantic sector of Antarctica. The samples covered a approximately 70 years time period from the 1920s to 1990. They were analysed by inductively coupled plasma sector field mass spectrometry and graphite furnace atomic absorption spectrometry.

Influence of anthropogenic sources on total gaseous mercury variability in Grenoble suburban air (France).

Total gaseous mercury (TGM) has been monitored at Champ sur Drac, a suburban site of Grenoble in southern east France. TGM measurements have been made over 4 periods of approximately 10 days throughout 1999-2000 using cold vapour atomic fluorescence absorption technique. The first monitoring campaign was initiated on November 4, 1999, followed by three other campaigns respectively on January 12, 2000, April 10, 2000 and July 17, 2000.