Additional Details

Description

The U.S. Geological Survey, in cooperation with the Massachusetts Department of Environmental Protection, Massachusetts Department of Conservation and Recreation, and Tufts University, completed a study of bottom-sediment quality in selected lakes, rivers, and estuaries in the Mystic River Basin, 2001.;;03. More than 100 bottom-sediment grab samples and 8 bottom-sediment cores were collected from the study area that included the Lower Mystic Lake, Mystic River, Alewife Brook, Malden River, Island End River, Chelsea and Mill Creeks, and Boston Inner Harbor. Sediment grab and sediment core samples were tested for the presence of pesticides, polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls, and trace elements. Both types of samples were generally enriched in toxic elements, in particular, arsenic, chromium, copper, lead, silver, zinc, and PAHs with respect to background concentrations and concentrations measured in sediment from other urban rivers. There were only a few detections of pesticides and no polychlorinated biphenyl detections above detection limits. Locally, concentrations of most trace elements and PAHs were lower in the sediments in the Mystic River Basin than in the lower Charles River, but higher than or equal to concentration in the Neponset River, with the notable exception of arsenic. Some chemicals also are in sufficiently high concentrations in Mystic River sediment to pose a threat to benthic organisms and potentially to cause health risks to humans if they come in contact with the sediment. Increasing concentrations with sediment depth in cores show that the deposition of trace elements and PAHs has substantially declined over the past 50 years or so. However, concentrations of PAHs are generally higher in the top few centimeters of sediment, indicating that sediment contaminant concentrations in the basin remain elevated above background.

Survey Date

2005

Print Date

2005

Two Sided

Yes

Pieces

1

Languages

English