Chemical combinations may increase risk.

• Position: Cancer

Amid a global cancer epidemic, a task force of 174 scientists from research and medical Institutions In 28 countries have concluded that average dally exposure to mixtures of chemicals might increase the risk of cancer beyond the risks from Individual chemicals on their own. The researchers were assembled by the nongovernmental organization "Getting to Know Cancer" to tackle longstanding theories and concerns over the relationship between combinations of commonly encountered chemicals and the development of cancer.

"This Is an area that merits considerable attention and where Interdisciplinary and international collaboration Is needed," notes project contributor David Carpenter, director of the Institute for Health and the Environment of the University at Albany (N.Y.). "The science In this field Is changing rapidly. Although we know a lot about the individual effects of chemicals, we know very little about the combined and additive effects of the many chemicals that we encounter every day in the air, in our water, and in our food."

According to the research group, the current national paradigm for testing chemicals rarely considers the synergistic or complementary roles of chemical mixtures. Safety testing of exposure to combined chemicals is nearly absent in the U.S. and Canada.

From the thousands of chemicals that the general...