Smoking kills over seven million people worldwide every year and is ‘one of the biggest public health threats the world has ever faced', the World Health Organization (WHO) has said.

It estimates that around 1.1 billion people smoke worldwide and 80% of these live in low and middle-income countries.

Tobacco kills up to half of its users and of the seven million deaths every year, over six million are the result of direct tobacco use. Some 890,000 are the result of exposure to second-hand (passive) smoke.

The WHO pointed out that there are more than 4,000 chemicals in tobacco smoke, 250 of which are known to be harmful to human health. More than 50 are known to cause cancer.

It is highlighting the dangers of smoking to coincide with World No Tobacco Day (May 31), which this year, is focusing on the impact of tobacco on cardiovascular health.

Cardiovascular disease (CVD) kills more people worldwide than anything else, and tobacco use is the second leading cause of CVD, after high blood pressure.

Meanwhile, at a conference to mark World No Tobacco Day in Ireland, the HSE pointed out that with more quitters than smokers here, a lot of progress has already been made in this area. However, challenges remain as smoking prevalence has not reduced equally across the population.

New research shows that one in four men and one in five women still smoke and the habit is now most common among young adults. Meanwhile, poorer and more marginalised groups are not quitting to the same extent as other groups.

Speaking at the conference, Dr Paul Kavanagh, the HSE's clinical and research lead for its Tobacco Free Ireland Programme, said that 'a social gradient in smoking is clear'.

"Smoking is less common among those from more affluent groups compared to those from less well-off groups. Smokers from more affluent groups and with higher levels of education are also the most likely to quit. We need to understand that differences in smoking behaviour are the leading cause of inequalities in health across society," he commented.

Meanwhile, the HSE's national lead for Tobacco Free Ireland, Martina Blake, pointed out that occassional smoking, sometimes referred to as social smoking, 'is an emerging challenge'.

"Some 4% of smokers in Ireland smoke occasionally. They are more likely to be younger and more affluent. It is important that people who are occasional smokers understand the true risk to their health, versus the benefit of avoiding this potentially life-threatening behaviour," she said.

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