Laser Ablation of Calcareous Shells and Skeletal Elements Coupled to Mass Spectroscopy as a Method of Determining the Spatial and Temporal Extent of Heavy Metal Pollution in Aquatic Species

Focus Area

Water Quality/Wetlands


Natural Resources




Under $99,000



Research Idea Scope

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.  Like wise the geographical extent of the pollution over time should be able to be read where a point source exists.

Urgency and Payoff

This research would allow an accurate determination of the extent and timing of pollution from point sources such as highway runoff culverts affecting sessile aquatic species. It could also provide a method to distinguish between current and historical sources of pollutants and their extent.

Suggested By

William Van Peeters, Resource Center San Francisco Office FHWA DOT, Telephone: 415 744 0116

[email protected]