Health warnings placed on tobacco product packages are effective, but few countries have adopted an international treaty that mandates such warnings, UPI reported May 21.

Tobacco health warnings support the intention to quit tobacco use, discourage the intention to start using, and increase cessation rates, according to research cited in the Centers for Disease Control and Prevention's (CDC) May 22, 2009 issue of Morbidity and Mortality Weekly Report. The CDC also noted that the effectiveness of warning labels increases with the size of the warning, the use of graphic images, and prominent placement on tobacco packaging.

However, the study found that the World Health Organization's Framework Convention on Tobacco Control, which legally mandates the use of tobacco health warnings by member countries, has not been widely implemented.

Using data reported to the World Health Organization (WHO), the MMWR study showed that 44 percent of countries did not require any warning labels. Of those countries that did require warnings, 40 percent called for labels that covered less than 30 percent of the packaging, and only 3 percent had warnings that covered half or more of cigarette packs.