And more than half of the tobacco-related deaths occurred in just four countries - China, India, the United States and Russian Federation.
The study said Pakistan, Panama and India stand out as three countries that have implemented a large number of tobacco control policies over the past decade and recorded marked declines in the prevalence of daily smoking since 2005, compared with decreases recorded between 1990 and 2005.
After three years of holding steady at about 66 percent, support for a comprehensive statewide smoke-free law among adults queried in the latest Kentucky Health Issues Poll (KHIP) jumped five points over the past year to 71 percent. The study found that one in four men is a daily smoker, while one in every 20 women is a smoker.
But working against them is the state's population of smokers more people smoke in Kentucky per capita than anywhere else in the country and the state's long history of tobacco growing that has sustained generations of farmers. Around 6.4m deaths were attributed to tobacco during 2015, with China, India, the USA and Russian Federation making up over half of that number.
The study looked at 195 countries and territories between 1990 and 2015 and found that smoking still seems to be a leading risk factor for death and disability.
But 15 percent of American adults were still regular smokers in 2015. This fits with a more general trend the study found: Male smokers are most commonly found in middle-income countries, while women are more likely to be daily smokers if they live in the world's wealthiest countries.
Apparently, tobacco control policies don't have the expected effect on the population.
Georgetown hires Patrick Ewing as men's basketball coach
With the 7-foot center leading the way, Georgetown played in three national championship games, winning it all in 1984. He was an NBA All-Star 11 times and won a second Olympic gold medal as a member of the first Dream Team in 1992.
Worldwide, between 1990 and 2015, smoking prevalence decreased by nearly a third (29.4 per cent) to 15.3 per cent in 2015. That's not to say there hasn't been any progress - far from it. Smoking rates in men dropped from 35 percent in 1990 to 25 percent in 2015 while for men the smoking rates dropped from 8 percent to 5 percent from 1990 to 2015, respectively.
"Tobacco is the only legal drug that kills many of its users when used exactly as intended by manufacturers", WHO.
Explaining the possible cause for the rise in numbers, renowned psychiatrist Dr S. Nambi said, "Dependency is a major factor why many fail to let go".
Dr. Salvatore Bertolone, pediatric oncologist, talks about a smoking ban, e-cigarettes and a cigarette tax.
Smoking cigarettes is much unsafe than we believed. "The more we know, the better we can target our efforts, the greater incentive national governments have to take action, and the more death and disease we can prevent", said Michael R. Bloomberg.
To date the initiative has successfully supported 59 countries in passing laws or policies, reaching almost 3.5 billion people and saving an estimated 30 million lives. Increased cigarette prices encourage smokers to either quit or smoke less, and discourage non-smokers to start.
The study was funded by Bloomberg Philanthropies and the Bill & Melinda Gates Foundation.