increased risk of lung cancer; the risk doubles if they were exposed as children and also increases if exposed at work or play.

The added risk is not huge. But the reality that secondhand smoke causes 3,000 or so lung-cancer deaths adds to the overwhelming case made by previous studies for more stringent controls to limit tobacco's damage. There's simply no reason asthma patients should suffer a million attacks and 300,000 kids respiratory infections each year so smokers can feed a habit.