Organisms pick up some heavy metals in proportion to their exposure in aquatic systems, they then deposit these elements along with calcium into their calcareous shells or skeleton. Many of these animals (mollusks, corals, fish) produce growth rings that provide a temporal record of their exposure to pollutants. If a cross section of these rings are made, and a laser is used to vaporize a very small dot of this material within an annual ring and the fumes are then taken to a Mass Spectrometer and analyzed for the ratio of calcium to the Heavy Metal of interest a year by year record of the animals exposure to the pollutant may be read.  Using long lived mollusks, and overlapping their records an extensive temporal record of the pollutant history could be made.  Like wise the geographical extent of the pollution over time should be able to be read where a point source exists.  The levels metal pollution during historic and prehistoric times may also be readable from buried shells. I propose to use the Laboratory and basic technique used by UC Davis Veterinary School professor Dr. Swee Te on salmonid otoliths. Dr. Te and I have discussed the technique over a number of years and believe it feasible and useful. We propose to start with a series of feasibility tests to determine the best species to use and to determine the accuracy and precision possible with the method.