Statistical comparison of heavy metal concentrations in various louisiana sediments.

The use of statistical 't' tests were used to determine lead, zinc, and cadmium enrichment in various Louisiana sediments. Both absolute metal concentrations and trace metal/conservative metal concentration ratios were used in comparing sampled sites to a 110 m deep background core taken just off the mouth of the Mississippi River. Concentration ratios were used to reduce the effects of certain chemical and physical sediment characteristics on the quantity of metal contained in a given sediment.Results from the comparison of sample sites to the background reveal metal enrichment at several sites. The University Lake sampling sites exhibit both lead and zinc enrichment when using both the concentration alone and ratio methods of comparison. Additionally, cadmium enrichment is indicated in the sediments of University Lake when using only the ratio method of comparison. Several sampled sediments in and around the New Orleans metropolitan area exhibited lead and cadmium enrichment.