Speciation and Sources of Toxic Metals in Sediments of Lake Chapala, Mexico

Heavy metals chemical speciation in Lake Chapala sediments was studied using sequential extraction to assess the mobility of potentially biotoxic metals and to elucidate their sources. Lake water quality was also studied. Results show Cd, Pb, Cr present in exchangeable and carbonate fractions indicating anthropogenic origin. An ecologic history indicates anthropogenic sources of Cd, Pb, Cr during 1960-2006. Risk Assessment Code indicates very high risk of pollution for water column due to high potential detachment of heavy metals.