http://www.theguardian.com/environment/2015/mar/29/world-pollutionwatch-smoking-ban-china
Starting with Berkeley, California in 1997 cities, regions and whole countries have banned indoor smoking in public places. Ireland introduced the first nationwide ban in 2004 and various types of restrictions are now in place in 92 countries from Albania to Zambia. This year’s planned indoor smoking ban in China will mean a huge increase in the global population covered.
Initially prompted by concerns about second-hand smoke and lung cancer risks these bans have yielded far greater benefits than the first campaigners can have anticipated.
As a tool to improve indoor air pollution, smoke free legislation has been very effective. Airborne particles decreased by an average of 86% in Scottish bars. In Spain, urine samples from non-smokers showed less tobacco smoke exposure, especially on Fridays and weekends. But it is the decrease in heart attacks that is most striking. Studies in 47 locations show that indoor smoking bans were followed by an average 12% decrease in heart attacks. In Scotland this was 17%. The English figure was less at 2%, with the biggest changes seen in men under 65. England was the last part of the UK to introduce smoke free legislation and the lower figure was perhaps due to many restaurants and workplaces already being smoke-free but a 2% decrease meant 1,200 fewer heart attacks in the first year.
Other studies have shown 15% fewer hospital admissions for childhood asthma. Despite fears, there is no evidence of increased smoking in cars or homes; in Scotland smoking in homes with children decreased.