Toxic Elements in Aquatic Sediments: Distinguishing Natural Variability from Anthropogenic Effects.

Regressions of aluminum against potentially toxic elements in the sediments of freshwater aquatic systems in Louisiana were used to distinguish natural variability from anthropogenic pollution when elemental concentrations exceeded screening effects levels. The data were analyzed using geometric mean model II regression methods to minimize, insofar as possible, bias that would have resulted from the use of model I regression. Most cadmium concentrations exceeded the threshold effects level, but there was no evidence of an anthropogenic impact.

Pathogen indicator microbes and heavy metals in Lake Pontchartrain following Hurricane Katrina.

Storm surge and several breaches of the New Orleans, Louisiana levee system caused flooding of more than 80% of the city following Hurricane Katrina in August 2005. Most of the floodwaters pumped out of the city were discharged to Lake Pontchartrain. Lake water and sediment samples were collected during September 19 to October 9, 2005 to determine the possible impact of the dewatering operation on Lake Pontchartrain.