A new Health Canada poll finds that 57 percent of smokers said that they are not affected by graphic health warnings on cigarette packs, compared to 52 percent five years earlier, the Canwest News Service reported July 4.

Also, 43 percent of smokers who are considering quitting called the warnings not very effective or not effective at all, up from 40 percent. Conversely, just 14 percent of smokers and 20 percent of prospective quitters consider the warnings very effective, the July 2008 survey found, down from 18 percent and 25 percent five years ago.

The warnings include images of cancerous lungs, mouth cancers, and heart disease caused by smoking as well as text messages. However, the warnings have not been changed in seven years and may be becoming stale to smokers, experts said. "You're not going to see a major consumer product company leave their television ads unchanged for seven years," noted policy analyst Rob Cunningham.

Most smokers are aware of the warnings, but 22 percent of smokers and 19 percent of those contemplating quitting say they never look at the images or text, up from 15 and 11 percent, respectively.