The old saying “monkey see, monkey do” certainly applies to teenagers.

They often emulate foolhardy behavior they witness.

For example, studies have shown that movies depicting smoking can actually encourage teens to light up.

Can material on the Internet have the same effect?

A study published recently in the journal Pediatrics took a first step toward answering this question.

In it, researchers assessed how much tobacco-related content teenagers might encounter as they surf the Web.

They tracked the online activities of almost three-hundred-fifty youths, ages fourteen to seventeen, over a thirty-day period.

Altogether, the teens viewed about one-point-two-million Web pages.

When researchers analyzed the pages, they found eighty-seven-hundred had tobacco-related content.

That’s less than one percent of the total.

About nineteen-hundred pages contained pro-tobacco material, including advertising. Sixteen hundred contained anti-tobacco material, and five-thousand pages referred to tobacco without clearly promoting or opposing it.

Almost half the subjects saw at least one Web page with a pro-tobacco message.

Much of the tobacco content appeared on social networking sites such as MySpace.

And many times the pages with tobacco material also contained references to drug use and sexual activity.

The researchers made a cursory effort to determine how many of the participants smoked. But the results didn’t clearly indicate whether online tobacco references encourage or discourage smoking.

So while more research is needed, here’s what we think… if you have teenagers in your home, let them know tobacco use is a bad idea.

We can’t guarantee they’ll listen.

But at least they’ll know where you stand.