Films that depict smoking should be rated 'R' so that children would be prohibited from seeing them without parental consent, an activist group says.

The Newark Star Ledger reported March 3 that the group Smoke Free Movies, founded by University of California at San Francisco medical professor Stanton Glantz, says that more movies are portraying smoking even as actual smoking rates decline. Some of the year's best movies, including "Brokeback Mountain," "Crash," "Munich," "Capote," and especially "Good Night, and Good Luck," include smoking scenes.

"There is more smoking in movies today than there was in 1950, and the percentage of the population that smokes is a little less than half what it was in 1950," Glantz said. "So movies are not reflecting this major change."

A study from Dartmouth Medical School says that adolescents exposed to smoking in movies are more likely to smoke themselves. The Smoke Free Movies campaign has been discussed at Congressional hearings and has won endorsements from major medical groups. Attorneys general from about 30 states have called for DVDs to carry warnings on films that show smoking.

However, the Motion Picture Association of America (MPAA) denies that depictions of smoking have increased in recent years, and is resisting calls for R ratings on movies with smoking. "Movies are about human behavior, and smoking is a human behavior," said MPAA spokesperson Kori Bernards. "A lot of other human behaviors are depicted in movies."

The Smoke Free Movies proposal calls for an R rating for smoking portrayals except those showing historical figures or those portraying smoking in a negative light. The group also is calling for filmmakers to ban product identification, put disclaimers in their credits saying they don't take money from the tobacco industry for product placement or smoking depictions, and to run antismoking ads before movies that show smoking.