Second-hand smoke kills more that 600,000 people each year worldwide, according to the first study to assess the global impact of passive smoking. That means one in every 100 deaths can be tied to second-hand smoke exposure.
About 165,000 of these deaths are among children. Youngsters are more heavily exposed to second-hand smoke than any other age group, and are not able to avoid its main source - their close relatives who smoke at home. Furthermore, children are the group for which there is the strongest evidence of harm attributable to second-hand smoke.
This exposure was estimated to have caused 379,000 deaths from ischaemic heart disease, 165,000 from lower-respiratory-tract infections, 36,900 from asthma and 21,400 from lung cancer.
The research was led by Annette Pruss-Ustun of the World Health Organization in Geneva and published in The Lancet.