A new way to inherit environmental harm.

• Author: Montague, Tim
• Position: Biodevastation - Reprint - Essay

New research shows that the environment is more important to health than anyone had imagined. Recent information indicates that toxic effects on health can be inherited by children and grandchildren, even when there are no genetic mutations involved. [1] These inherited changes are caused by subtle chemical influences, and this new field of scientific inquiry is called "epigenetics." [2]

Since the 1940s, scientists have known that genes carry information from one generation to the next, and that genes gone haywire can cause cancer, diabetes, and other diseases. But scientists have also known that genes aren't the whole story because identical twins can have very different medical histories. One identical twin can be perfectly healthy while the other develops schizophrenia or cancer, so the environment must play a significant role, not merely genes.

What's surprising is that scientists are now revealing that these environmental effects can be passed from one generation to the next with far-reaching implications for human health. Epigenetics is showing that environmental influences can be inherited even without any mutations in the genes themselves [1] and may continue to influence the onset of diseases like diabetes, obesity, mental illness and heart disease, from generation to generation.

In other words, the cancer you get today may have been caused by your grandmother's exposure to an industrial poison 50 years ago, even though your grandmother's genes were not changed by the exposure. [1] Or the mercury you're eating today in fish may not harm you directly, but may harm your grandchildren.

This emerging field is causing a revolution in the understanding of environmental influences on health. The field is only about 20 years old, but is becoming well established. In 2004, the National Institutes of Health granted $5 million to the Johns Hopkins Medical School in Baltimore to start the Center for Epigenetics of Common Human Disease.

The latest information appears in a new study by Michael Skinner and colleagues at the University of Washington, published in Science magazine. Skinner found that mother rats exposed to hormone-mimicking chemicals during pregnancy gave birth to four successive generations of male offspring with significantly reduced fertility. [3] Only the first generation of mothers was exposed to a toxin, yet four generations later the toxic effect could still be detected.

Prior to this study, scientists had only been able to...