Students who visited such cigarette stores on a regular basis were at least twice as likely to try smoking as those who visited infrequently, a study conducted by researchers from Stanford University School of Medicine said.
The study was based on surveys of 11 to 14-year-olds at three middle schools in Tracy, California, and assessment of cigarette advertisements at stores near the schools.
The survey included questions about students' smoking experience as well as how often they visited stores with lots of cigarette ads - convenience stores, gas stations and small groceries - and then checked back later, first at one year and then at 30 months.
Of the 2,110 students surveyed in 2003 when the study began, 1,681 reported never smoking. A survey of these non-smoking students a year later revealed 18 percent of these students had smoked over the year, at least one puff, and that smoking initiation was much more prevalent among the students who had reported frequent visits to stores with the most cigarette ads, Xinhua reported.
Among those who had reported visiting such stores at least twice a week, 29 percent had taken at least one puff in the previous year. Among those who rarely visited - less than twice a month - only nine percent had smoked at all.
A survey 30 months after the study began found that by then 27 percent had tried smoking.
To measure the exposure to ads, the researchers multiplied the frequency of visits by the number of ads in stores near the schools - cigarette-branded ads, product displays and functional objects, like clocks and trash cans.
On average, students experienced 325 cigarette-brand ads per week, ranging from an average of 114 among infrequent shoppers to 633 among those who shopped frequently.
"I was surprised by the sheer number of cigarette brand ads in convenience stores near schools," said Lisa Henriksen, senior research scientist at the Stanford Prevention Research Centre. "The exposure is unavoidable. It's impossible to miss."
Lawmakers should consider barring such marketing efforts from convenience stores, gas stations and small groceries, the researchers said in the study published in the latest issue of Pediatrics.