The first global study into the effects of passive smoking has found it causes 600,000 deaths every year. One-third of those killed are children, often exposed to smoke at home, the World Health Organization (WHO) found. The study...found that passive smoking is particularly dangerous for children, said to be at higher risk of sudden infant death syndrome, pneumonia and asthma...The global health body said it was particularly concerned about the 165,000 children who die of smoke-related respiratory infections, mostly in South East Asia and in Africa...As well as being at increased risk of a series of respiratory conditions, the lungs of children who breathe in passive smoke may also develop more slowly than children who grow up in smoke-free homes.