A study has brought out that passive smoking is the cause of 600,000 deaths every year including three-fourth of the proportion of women and children.

The report was written by experts mostly from the World Health Organization (WHO). They found that children and women are the most vulnerable to second-hand smoke. One-third of the children who fall prey to passive smoking are children.

The study covered 192 countries and it revealed that though, in some countries, smoking is banned in public places, but children and women get affected by second-hand smoke in their homes.

Passive smoking increases the risk of sudden infant death syndrome, pneumonia and asthma. It can also lead to heart disease, respiratory illness and lung cancer.

Another cause of concern regarding passive smoking is that it is the reason behind 165,000 child fatalities, the world over. Most cases are found in South East Asia and in Africa, as children living in such regions are more prone to second hand smoke at their homes.

The combination of infectious diseases and second-hand smoke proves lethal, as expressed by Armando Peruga of the WHO's Tobacco-Free Initiative and lead researcher of the study.

Women are more likely to be exposed to second-hand smoke and about 281,000 of them die of passive smoking related ailments every year.