Man-Made and Natural Carcinogens: Putting The Risks In Perspective

Environmental groups have waged an aggressive campaign to ban Alar, the controversial chemical used on apples to pro- mote uniform ripening and prolong shelf life. They want it banned because a breakdown product of Alar, UDMH, has been shown to cause liver tumors in mice and may pose a cancer risk to humans, especially children. The Alar controversy has heightened people’s awareness—and anxiety—about cancer risks of. man-made chemicals in our environment. But little publicit

The Scientist Staff
Jul 9, 1989

Environmental groups have waged an aggressive campaign to ban Alar, the controversial chemical used on apples to pro- mote uniform ripening and prolong shelf life. They want it banned because a breakdown product of Alar, UDMH, has been shown to cause liver tumors in mice and may pose a cancer risk to humans, especially children.

The Alar controversy has heightened people’s awareness—and anxiety—about cancer risks of. man-made chemicals in our environment. But little publicity is given to natural substances in our food that also cause cancers in laboratory animals. By informing the public of these “natural carcinogens,” we may gain a more balanced perspective on the relative danger of man-made chemicals.

Bruce N. Ames of the University of Califomia' Berkeley, has studied natural pesticides produced by all plants to ward off insects, fungi, and other predators. In a recent letter to Science (244:755-7, May 19,1989), Ames points out that we...