It used to be that many more boys than girls took up smoking. But now the gap is narrowing, according to a new study published this week in the international medical journal The Lancet. A second study, also in The Lancet, has found that Indian children start smoking at a younger and younger age. Public health officials are alarmed by the new trends in tobacco use.
Experts say the ratio of adult male smokers to female smokers is pretty much a constant - four to one - the world over.
But researchers were not prepared for what they found when they surveyed 750,000 boys and girls in 131 countries and the West Bank and Gaza Strip.
Charles Warren is with the Office of Smoking and Health at the U.S. Centers for Disease Control and Prevention in Atlanta, Georgia, and a co-author of the study that found a much narrower ratio - two to one - of male to female smokers among 13- to 15-year-olds.
"The expectation would be much higher rates among males than females just based on the adult data. When we look at our data, it's like, "Wow," he said.
The the results were based on answers to the Global Youth Tobacco Survey, sponsored by the CDC and the World Health Organization.
Between 1999 and 2005, researchers found that the smoking habits of girls were close to boys everywhere they sampled. In one region, the Americas, investigators found that 17 percent of youth are lighting up - a statistic that's the same for boys and girls.
"And what we are seeing is a big change that suggests not that the boys are decreasing in use, but that the girls are increasing in use. So this is a bad news finding," he said.
And there were other disturbing findings. If offered a cigarette by a friend or family member, 18 percent of boys and girls said they might smoke one within a year, increasing the likelihood that they'll become smokers.
And nearly 50 percent of boys and girls said they were exposed to secondhand smoke, a risk factor both for smoking initiation and disease.
In a separate study, researchers surveying nearly 12,000 sixth and eighth grade students in India found that the younger children smoked almost four times as much as the older ones.
It was not what Cheryl Perry, a professor of community health at the University of Minnesota, expected to find. "So, we took a look at that data over and over again because it really means there is an increase in tobacco with an earlier cohort. And this is very alarming," she said.
Perry, who co-authored the study with colleagues in India, says the finding has long term public health implications..."because the earlier you start using tobacco, the more likely it is that you will become addicted to continue using. And actually, there are some long term studies showing that the earlier you start smoking anyway, the more likely you are to die of lung cancer," she said.
Researchers say as countries become more westernized, people have more money to spend on tobacco products.
Warren says its clear cigarette advertising is reaching its target audience, youth. And it's worked, our data unfortunately showing that their efforts have paid off, especially among the young girls," he said.
While public health officials find the trend disturbing, they say the findings will likely help them guide anti-smoking campaigns toward the youth.