Analysis Of Lead From Atmospheric Deposition And Sediment To The Monterey Bay

One route of lead exposure in humans is through a diet of contaminated shellfish, specifically bivalves. Those organisms are exposed to lead from a variety of sources, both natural and anthropogenic that may be distinguished by differences in their isotopic signature. Consequently, measuring the isotopic ratio of lead in bivalves provides information on the sources of lead in those organisms. This is being done with various end-members (e.g., sediment, phytoplankton, rain water and sea water) collected concurrently with mussels. Mussel samples have been collected and prepared from several sites in Monterey Bay, which previously was found to have the highest levels of lead in bivalves in the National Mussel Watch Program.¹ Preliminary data show that concentrations of lead in rain water range from 40-260 ng/L; and lead concentration in the other environmental matrices and mussels are now being measured for an assessment of the current level of lead contamination of mussels in Monterey Bay. Then the sources of lead in these samples will be characterized by their isotopic signatures. As soon as the analyses are completed I plan to do a time series of mussels collected from Monterey Bay, over the past 20 years to determine whether effort to remediate the lead contamination problem has been successful.

 

1. Flegal, A.R.; Rosman, K.J.R.; Stephenson, M.D. Environ. Sci. Technol., 1987, 21, 1075-79.