THE ENRICHMENT OF ARSENIC AND OTHER METALS IN SALINAS DE SAN PEDRO LAGOON, CALIFORNIA IN A SPECIFIC BIOGEOCHEMICAL AND TECTONIC-GEOMORPHIC SETTINGS

The distribution of arsenic pollution can be explained by geochemical mechanisms that operate in specific biogeochemical and geologic settings. Concentration of Metals was determined in Salinas de San Pedro, California. Analysis of the sediment cores for heavy metals (Ag, Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se, Sr, Ti, V, and Zn) was conducted with Inductively Coupled Plasma Optical Emission spectrometry (ICP-OES) for 20 sites. In general values for some of these metals tested indicate that the concentrations of metals found in this heavy urbanized salt marsh were generally higher than those usually reported from industrialized salt marshes and estuaries. The concentrations in mudflat sediments (silt and clay) varied greatly for each metal, with concentration values (mg/g) ranging from 1.05-4.8 (Al); 0.003-0.011 (As); 0.001-0.005 (Cd); 0.02-0.82 (Cr); 0.085-0.47 (Cu); 5.98-14.22 (Fe); 0.06-0.19 (Mn); 0.03-0.67 (Ni); 0.05-0.38 (Pb); <0.008-0.069 (Se); 0.18-0.63 (Ti); 0.040-0.091 (V) and 0.149-0.336 (Zn). Mean concentration factor (CF) rankings of core sediments samples were in As>Cd>Cr>Cu>Fe>Mn>Pb>Se>Sr>Ti>V>Zn. The CF value for As lies in the ranges 1 to 3 indicating a moderate level of contamination by this metal. The most likely sources for these element enrichments (especially As, Cr, Pb, Se, Ti, and Zn) are to be natural hydrogen sulfide gas discharge through local fault line (sulfide oxidation) and intensive industrial and boating in the last two decades. Results of this research study indicate that the potential toxicity of salt march sediment by arsenic and other metals could cause adverse biological effects to the biota directly and the human health indirectly through food chain.