Chemicals can turn genes on and off; new tests needed, scientists say.

A National Academies workshop examined the evidence of epigenetic effects and considered whether the thousands of chemicals in use today should be tested for them. Some pollutants and chemicals don't kill cells or mutate DNA. Instead, they may be more subtle, muting genes or turning them on at the wrong time, which can lead to diseases that are passed on for generations. Asthma in New York City children exposed to traffic exhaust is an example, experts say.

By Bette Hileman
Environmental Health News
Aug. 3, 2009
http://www.environmentalhealthnews.o...etics-workshop

Exposure to gene-altering substances, particularly in the womb and shortly after birth, “can lead to increased susceptibility to disease,” said Linda S. Birnbaum, who was named director of the National Institute of Environmental Health Sciences and of the National Toxicology Program in December. “The susceptibility persists long after the exposure is gone, even decades later. Glands, organs, and systems can be permanently altered.”

Animal studies indicate that some environmental chemicals cause epigenetic changes that trigger breast and prostate cancer, obesity, diabetes, heart disease, asthma, Alzheimer’s, Parkinson’s disease and learning disabilities, she said. And some new human studies are now adding to the evidence.

“There is a huge potential impact from these exposures, partly because the changes may be inherited across generations. You may be affected by what your mother and grandmother were exposed to during pregnancy,” Birnbaum said.