If you're an investor in tobacco concerns such as Altria (NYSE:MO) (formerly Philip Morris), R.J. Reynolds (NYSE:RJR), and Carolina Group (NYSE:CG), then you have some new cause for concern. Just what you needed, right? After all, tobacco companies are already dealing with enough headaches from litigation. Well, there's news out now that leaves antismoking advocates relieved and tobacco investors worried.

According to the Centers for Disease Control and Prevention, smoking among the nation's teens was recently at its lowest level in a generation -- since 1975. About 22% of teens (one in five) surveyed reported being a smoker in 2003. That's nearly 40% lower than the 36% who smoked in 1997. The Associated Press reports, "The drop was so dramatic that for the first time in more than two decades, the percentage of high school smokers is lower than the percentage of adult smokers." Public antismoking campaigns and hefty increases in the cost of smoking are both credited for the drop in numbers.

The price of a pack of cigarettes is approaching $6 and up in some states. According to the National Association of Convenience Stores, tobacco prices surged 31% in 1999, 11% in 2000, 8% in 2001, and 9% in 2002. A 10% spike in the price of cigarettes is estimated to decrease smoking among young people by around 7%.

This news is worrisome to those who profit from tobacco. The vast majority of smokers start smoking by the time they leave high school, and by then, they're addicted. If fewer young people start smoking, the industry will likely end up with a smaller customer base. Ironically, some of the antismoking campaigns were paid for by tobacco companies as part of a 1998 $206 billion legal settlement with many states.

Tobacco investors have a tough call. On the one hand, by many measures, tobacco companies look attractive as investments. Altria and R.J. Reynolds, for example, sport dividend yields north of 5%. But they're in a business that exposes them to considerable risks. And if the current trend remains in place, their consumer base may be shrinking.

Fortunately, investors have other places to turn. Our Motley Fool Income Investor newsletter recommends at least two investments that pay out dividends each month (try it free). Also, real estate investment trusts (REITs) offer another road to high dividends.

If you've got teenagers, consider encouraging them to visit our Teens and Their Money area, where they can learn how to become richer than you. Our Motley Fool Investment Guide for Teens book may also be of interest (it even includes a section on the cost of smoking).

L ongtime Fool contributor Selena Maranjian does not own shares of any companies mentioned in this article.