last updated: 6 September 2000

David, Carlos Primo

Carlos Primo C. David is a faculty (on study leave) of the National Institute of Geological Sciences in UP Diliman. He finished his BS and MS degrees in Geology from UPNIGS and is currently a DOST scholar taking his PhD at the Department of Geological and Environmental Sciences of Stanford University. He is also a research scientist at the Metal Bioavailability Lab of the US Geological Survey in Menlo Park, California.

CP David is doing research on the release of toxic metals to the environment, particularly from mine tailings and effluents. His thesis research involves the spill that occurred in Marcopper, Marinduque in 1996. He also does the seasonal monitoring of metals in sediments and bivalves from the San Francisco Bay and Clark Fork River, Montana for the USGS.

Research

TRACING TOXIC METAL RELEASE THROUGH TIME

All trace metals (Cu, Cd, Pb, Zn, etc.) above a certain concentration can be toxic to aquatic life, in extreme cases even to human population. One major source of metals is the waste generated from mining operations. Metals are in the form of either particulate matter (bound in sediments) or as dissolved constituents in water.

Conventional sediment/water sampling in a contaminated site is what is usually done. Another method for monitoring pollution in the marine environment that is currently being explored is the use of several coral species as indicators of metal contamination. Coral families like the Poritidaes form annual growth bands (much like tree rings) which can be subsampled and analyzed for metals. In other words, one may be able to determine the historic input of contaminants in the ocean by looking at the trend in metal concentrations from these growth bands.

The area of interest is the western coast of Marinduque, Philippines. In 1996, a huge volume of mine tailings was accidentally released in the near-shore region from the Marcopper mine. Preliminary analyses of corals indicate a spike in metal concentrations starting in the 1996 ring. Two other contaminated sites (contamination started in the mid 80's) in the island are likewise being explored.