A new study is showing that environmental toxins are leading to premature aging.

The study says a class of environmental toxins called gerontogens put humans at risk for accelerated again.  The toxins can be found in a wide range of items from second-hand cigarette smoke to UV rays and chemotherapy.

“Genetic studies have taught us only 30 percent of aging is genetic, meaning the other 70 percent comes from the environment,” Dr. Norman Sharpless told Fox News.  “Having a few [of these cells] is not a big deal.  But over the course of a lifetime, as they accumulate, they [contribute to] aging and many of the diseases we associate with aging.”

The study, published in Trends in Molecular Medicine, has allowed the doctors to create a test for substances to see their impact on aging.  The aging process begins when the body undergoes a process called senescence where healthy cells are damaged and are no longer able to divide.  The test will expose cells to substances until they cause the senescence process.

“Our work reasonably says cigarette smoking is the thing we could really do something about that would benefit the aging biology of a large number of people,” Dr. Sharpless said. “But we’re also reasonably certain there are other gerontogens we don’t know about yet.”