Sediment deposition and inventory of chemical contaminants in the tidal Anacostia River, Washington, DC
- Interstate Commission on the Potomac River Basin, Rockville, MD (United States)
- Texas A and M Univ., College Station, TX (United States)
- Coll. of William and Mary, Gloucester Point, VA (United States)
- Univ. of Maryland, Cambridge, MD (United States)
To determine the historical inputs and loads of sediment contaminants in the lower Anacostia River, six 3 meter gravity cores were collected in 1995. The down-core distributions of trace metals and organic contaminants (e.g., PCBs, DDTs, and PAHs) were determined. Dating of three cores using {sup 210}Pb indicate a substantial mixed layer in the upper 10 to 25 cm and an exponential {sup 210}Pb decrease to 3 meters. Sedimentation rates of 2 to 3 cm/yr were estimated and are in agreement with estimates based on pollen and sediment mass balance calculations. This suggests that bottom core sections are between 100 and 150 yrs old. However, contaminant levels were elevated in the bottom sections of most cores with levels of Pb, Cd, tPCBs, and tPAHs ranging from 23 to 610 {micro}g/g, 0.15 to 5.2 {micro}g/g, 3.9 to 1,745 ng/g, and 110 to 49,000 ng/g, respectively. These levels suggest either post-depositional migration of material or that {sup 210}Pb profiles are not representative of the true deposition. To help validate the {sup 210}Pb-age-depth profiles, the distribution of {sup 137}Cs is currently being determined for these cores. Generally, the depth distribution of most contaminants were surface maximum with lower concentrations at depth, or mid-depth maximum. However some cores had contaminant concentrations that increased with depth. The down core distributions and the results of the sub-bottom profiling will be used to help establish a better contaminant mass balance for the Anacostia River.
- OSTI ID:
- 460513
- Report Number(s):
- CONF-961149-; TRN: IM9718%%94
- Resource Relation:
- Conference: 17. annual meeting of the Society of Environmental Toxicology and Chemistry: partnerships for the environment - science, education, and policy, Washington, DC (United States), 17-21 Nov 1996; Other Information: PBD: 1995; Related Information: Is Part Of SETAC 17. annual meeting -- Abstract book. Partnerships for the environment: Science, education, and policy; PB: 378 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Occurrence of C[sub 10]-C[sub 13] polychlorinated n-alkanes in Canadian midlatitude and arctic lake sediments
Concentration of selected trace elements and PCBs in sediments from the Adriatic Sea