A worldwide study into the effects off passive smoking has found it causes 600,000 deaths every year. One-third of those killed are children, who are often exposed to smoke in there homes, the World Health Organization (WHO) found. The study, in 192 countries, found that passive smoking is particularly dangerous for children, said to be at higher risk of sudden infant death syndrome, pneumonia and asthma. Passive smoking causes heart disease, respiratory illness and lung cancer. "This helps us understand the real toll of tobacco," said Armando Peruga, of the WHO's Tobacco-Free Initiative, who led the study. Worldwide, 40% of children, 33% of non-smoking men and 35% non-smoking women were exposed to second-hand smoke in 2004, researchers found. This exposure was estimated to have caused 379,000 deaths from heart disease, 165,000 from lower respiratory infections, 36,900 from asthma and 21,400 from lung cancer. According to the study, the highest numbers of people exposed to second-hand smoke are in Europe and Asia and the lowest rates of exposure were in the Americas, the Eastern Mediterranean and Africa. The research also revealed that passive smoking had a large impact on women, killing about 281,000 worldwide. This is due to the fact that in many parts of the world, the study suggests, women are at least 50% more likely to be exposed to second-hand smoke than men. But for people who are looking to quit smoking there is always help, nearly all doctors clinics in the UK are offering smoking cessation services, which includes taking a course of Champix if deemed eligible by health officials.