London - Give smokers a wide berth — all 30ft (about 9m) of it.
Researchers have calculated this is the distance to keep in order to avoid the health dangers of second-hand smoke — even when outside.
Second-hand smoke is a significant health problem. The NHS says it contains more than 4 000 chemicals, many of which are linked to cancer. In the new research, from Seoul National University in South Korea, doctors measured levels of toxic chemicals at various distances from smokers who lit up outside on a rooftop.
“The minimum distance from a smoking source to prevent secondary smoke exposure should be at least 9m (30 ft),” say the researchers, who measured particulates in the air at various distances from the smoker. - Daily Mail