BOB HIRSHON (host):
Smoking risks across generations. I’m Bob Hirshon and this is Science Update.
It’s well-known that tobacco exposure, in the home or in the womb, contributes to childhood asthma. But those children’s future children may also be at risk – even if they’re never exposed themselves. Neonatalogist Virender Rehan of the Harvard-UCLA Medical Center and his colleagues exposed pregnant and nursing rats to nicotine. Predictably, their pups became susceptible to asthma. After they weaned, though, the pups grew up in a nicotine-free environment. Remarkably, the next, unexposed generation had high asthma rates too. Further experiments showed that early nicotine exposure alters DNA in testes and ovaries – which could explain how the first generation passed their asthma risk to the second. Rehan says that surveys of human families line up with the findings, but much closer study is needed. I’m Bob Hirshon for AAAS, the Science Society.