Smoking among Hawaii teenagers has plummeted in this decade, an encouraging trend that probably reflects many factors. Education, law enforcement, legal restrictions and the growing price of cigarettes, due to inflation and increased tobacco taxes, all played a role in steering children away from the addiction.

In 2000, 12.9 percent of middle school students and 24.5 percent of high school students were smokers, according to a survey by the state departments of Health and Education. Last year, only 4.2 percent of middle school students and 9.7 percent of high schoolers were smokers.

That is dramatic improvement, especially with the realization that most adult smokers took up the habit as teenagers. Once beyond that youthful stage, most people are less likely to plunge into what they understand by then to be an expensive, addictive and dangerous habit. Many factors have come into play in Hawaii:

» With growing evidence of the dangers of secondhand smoke and public support of restrictions, counties approved smoking bans by the end of the 1990s in workplaces and public facilities. The Legislature extended the bans last year to bars and other public places.

» Legislators enacted a law in 2006 raising the cigarette tax by 20 cents a year, now $2 a pack, to reach $2.60 a pack by 2011. Studies have shown that a 10 percent price increase results in a decline in smokers from 3 percent to 7 percent.

» Sting operations first showed that more than one-fifth of the merchants violated the law by selling cigarettes to customers under the age of 18. Continued stings have helped to reduce that to one in 20 merchants by 2004.