More Genes May Be Affected by Cadmium.

Duke University researchers studying primitive worms have found that as many as 31 different genes may react to the metal cadmium, an industrial additive and contaminant. Of these genes, 22 are unknown and have no previously known links to cadmium exposure.

The findings of assistant professor Jonathan Freedman and doctoral student Vivian Hsiu-Chuan Liao, of Duke's Nicholas School of Environment, were published in the November 27, 1998, issue of the Journal of Biological Chemistry.

"The important thing is that these new genes serve as starting points for studies in higher organisms," Freedman said. "They can serve as models from which to investigate how cadmium can be a carcinogen in humans. We can define toxicology pathways that have never been seen before."

Cadmium ranks seventh in the "Top 20 Hazardous Substances Priority List," published by the U.S. Environmental Protection Agency and the Agency for Toxic Substances and Disease Registry. It is used in metal coatings, nickel-cadmium batteries, and pigments. Ore smelting and fossil fuel combustion also release cadmium into the atmosphere.

In humans continually exposed to cadmium, the metal accumulates in the liver, lungs, and kidneys. Cadmium exposure has been linked to kidney damage, respiratory diseases, and neurological disorders. It is known to cause various cancers in rodents, and population studies suggest it causes human tumors, as well.

(Adapted with permission from RTP Viewpoints, Spring 1999.)