Smokers pass on risk of asthma to their unborn grandchildren

When a man exposes his son to second-hand smoke, he's also damaging his future grandchildren. Photo: Getty

Second-hand or passive smoke from tobacco is even sneakier than you might have thought, a new study suggests.

Let’s say you grow up in a household where nobody smokes. The air is clean and no one is entertaining you by blowing smoke rings.