Historical changes in lead in the eastern Canadian Arctic, determined from fossil and modern Mya truncata shells

Recent and fossil (8200 a BP) shells and their surrounding sediments were collected from three sites near Pangnirtung, Northwest Territories, in the eastern Canadian Arctic. Fossil shells were not recrystallized and still aragonitic. Lead levels were determined for the shells, and the concentration of major and minor elements as well as particulate lead extracted in the sediments. Lead levels in the fossil shells were approximately five times lower than those detected in the modern shells. Results of this study suggest that determination of pollutant levels in shells of bivalves may be an important and underutilized tool for environmental assessment.