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.
