In 1954, a landmark study by British scientist Richard Doll provided the first incontrovertible evidence that smoking causes lung cancer.
In the ensuing decades, governments began health campaigns against tobacco, requiring ever-tougher package warnings and enforcing restrictions on where and to whom it could be sold.
Half a century on from Doll's research comes another watershed year, this time with the right to smoke being called into question.
Laws against passive smoking have dramatically proliferated this year, shrinking the space where smokers can legally light up and casting them in the role of a huddled minority with an antisocial habit.
Since the start of this year, a dozen countries have introduced, or announced plans to introduce, laws that will toughen the ban on smoking in public places so that it includes restaurants, clubs and bars.
More countries, states and cities are likely to follow suit next year, say experts.
"We're very encouraged," said Carmen Auderalotez, technical officer with the World Health Organization's anti-smoking campaign, the Tobacco Free Initiative.
"These laws follow on from the gradual introduction of restrictions on smoking in the workplace, which is the key first step.
"These bans protect non-smokers and also help to create an environment where smoking is no longer considered acceptable or fashionable," she said.
California, in 1998, led the legal charge to eradicate tobacco smoke in the hospitality sector, but the vanguard has now been seized by Europe.
Ireland, on March 29, became the first country in the world to ban smoking not just in the eateries and pubs, but even company cars. It has been swiftly followed by Norway, while Sweden, Britain and Portugal have all unveiled plans for similar restrictions.
Sweden already has the lowest smoking rates of any country in the world -- less than a fifth of the adult population have the habit.
Auderalotez predicts that more US states and some African countries will be in line next year to roll back the right to smoke.
In Asia, though, it's a different picture, for in many countries, smokers can puff with few hindrances. The legal picture remains rather as it was in Europe some 15 to 20 years ago and possibly longer in the US.
According to World Bank figures, of the 1.1 billion smokers in the world, 43 percent are in the Asia-Pacific region.
The figure is headed by China, with 320 million smokers, the most of any nation. More than half of adult males smoke, and the prospect of any restriction of smoking in public places is extremely remote.
"Tobacco may eventually kill about 50 million of all the children and youth alive today in China," the US Centers for Disease Control says.
India, which has 240 million tobacco users, outlawed smoking in public places in May, but this is rarely enforced, campaigners say.
The big exception is the tiny Himalayan kingdom of Bhutan, which has become the first country in the world to not only outlaw smoking in public places but also bar all tobacco sales, a move set to take effect from Dec. 17.
Evidence about the dangers of passive smoking came to notoriety in 1992. The US Environmental Protection Agency (EPA) then estimated that each year tobacco smoke inhaled by non-smokers killed 3,000 Americans from lung cancer alone.
Further studies have pointed the finger at smoke in pubs, workplaces and homes as a major source of heart disease, asthma, chronic bronchitis and prematurely aged skin, among other problems.