Historical Trends in the Accumulation of Chemicals in Puget Sound. National211 Status and Trends Program for Marine Environmental Quality

摘要

The purpose of the study is to: (1) continue monitoring historical trends in the211u001econcentration of contaminants in Puget Sound sediments, and (2) quantify recent 211u001etrends in the recovery of contaminated sediments. Results from this study can be 211u001ecompared with those obtained in the 1982 study to determine whether sediment 211u001equality is still improving and to estimate the rate of recovery. A statistically 211u001esignificant reduction in sediment contamination over the past 20 years would 211u001eprovide empirical evidence that environmental regulation has had a positive 211u001eimpact on the water quality in Puget Sound. Chemical trends were evaluated from 211u001esix age-dated sediment cores collected from the main basin of Puget Sound. 211u001eChemical analyses included metals, polynuclear aromatic hydrocarbons (PAHs), PCBs 211u001eand chlorinated pesticides, nutrients (total nitrogen (N), and phosphorus (P)), 211u001ebutyltins, and total organic carbon (TOC). Sedimentation (cm/yr) and deposition 211u001erates (g/sq cm/yr) were estimated using a steayd-state Pb-210 dating technique.