Popis: |
Sediments adjacent to a kraft pulp and paper mill on western Nipigon Bay, Lake Superior, were examined for resin acids. Dehydroabietic acid was the predominant resin acid with surficial concentrations of less than 5–100 μg/g.The areal distribution indicated the mill to be the primary source of this compound. Depth profiles of the acid and core dating by 210Pb methods enabled the calculation of a mean sediment accumulation rate of 0.11 cm∙yr−1 and a half-life for the disappearance of dehydroabietic acid in the sediments of approximately 21 yr. A half-life of 0.12 yr was estimated for this compound in the water column. It appears, therefore, that the primary removal mechanism of dehydroabietic acid is degradation in the water column. |