Dr. Andrew G. Gault, Dept. of Earth, Atmospheric and Environmental Sciences, Universitat de Manchester, Anglaterra
Lloc, Sala d'Actes de l'Institut Jaume Almera, 12h.

The consumption of arsenic-rich groundwaters in Wet Bengal and Bangladesh is causing widespread deleterious health effects, with the situation in Bangladesh described as the largest poisoning of a human population in history. Elevated levels of arsenic have also been identified in aquifers located elsewhere in SE Asia, including northern Vietnam and southern Cambodia The mechanisms underlying the development of such high-arsenic
subsurface waters have been widely debated, however, the reductive dissolution of senic-bearing ferric (oxyhydr)oxides has become the prevailing theory. Nevertheless, the microbial component of this process has remained poorly characterized. We have used X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopies, in tandem with geochemical and microbiological investigations, to help improve our knowledge of the biological drivers of arsenic lization in SE Asian aquifers.