http://www.bbc.co.uk/news/health-26432111

"Passive smoking causes lasting damage to children's arteries, prematurely ageing their blood vessels by more than three years, say researchers. The damage - thickening of blood vessel walls - increases the risk of heart attacks and strokes in later life, they say in the European Heart Journal. In their study of more than 2,000 children aged three to 18, the harm occurred if both parents smoked."

Just ban it already; make it illegal. Either that, or tax more. Seriously, if the government wants to protect non-smokers, do something about it.