INVESTIGATING A SHINY KILLER

The door handle on your car, made of chromium, won't put you at risk, but workers in the chrome-plating plant that produced it have higher than normal rates of cancer. Elevated cancer rates show up among workers in paint factories where the metal is used as a pigment and among welders who work with stainless steel. "What you have," says Chemistry Professor Karen Wetter hahn wryly, " is an occupational health hazard."

Since Wetterhahn came to Dartmouth in 1976, she has been trying to discover how the metal causes cells to mutate. So far, she has shown that some forms of chromium become mutagenic only after the body's metabolism activates them. For instance, some substances in cells apparently change chromimum 6, which is harmless to DNA, into DNA-damaging chromium 5. Wetterhahn has identified several of these substances. A second phase of her research is aimed at characterizing the damage in DNA exposed to toxic forms of chromium.

When Wetterhahn began her project, she was assisted by two undergraduates. Today, the program involves ten people, including graduate students in biochemisty, chemistry, and pharmacology toxicology, as well as undergraduates.

Students are helping a chemist examine a cancer-causing metal.