A study conducted by a U.S. Naval Reserve medical officer concluded that Marines and sailors in Iraq use tobacco at twice the rate of other Americans, with about half of smoking troops beginning tobacco use only upon reaching a combat zone, MedPage Today reported Oct. 29.

The survey of 408 participants from the 3rd Infantry Battalion, 23rd Marine Regiment, 4th Marine Division -- deployed to Al Anbar province from September 2007 to April 2008 -- found that 64 percent used some form of tobacco, compared with 30.4 percent of the general U.S. population and 38.9 percent of service members returning from Iraq in 2004.

Fifty-two percent of the respondents smoked cigarettes, 36 percent used smokeless tobacco, and 24 percent used both.

"Such abuse will likely cause a greater negative impact on the long-term health of U.S. veterans than combat-related injuries," said study author Michael Wilson at a meeting of the American College of Chest Physicians.

Forty-five percent of the tobacco users did not use tobacco before joining the military. The majority of tobacco users said that their use increased after joining the military (65 percent) and being deployed to Iraq (66 percent).

"The U.S. military seems to have a culture that fosters significantly higher use of tobacco products, particularly during combat deployments," Wilson said, adding that troops used tobacco as a stimulant to stay alert as well as for stress relief and a way to ease the boredom of long periods of inactivity.

Fifty-two percent of respondents said that a military dentist or physician had advised them to quit using tobacco for health reasons, while 55 percent of respondents expressed a desire to quit.

Improved smoking-cessation programs in the military would prevent significant health problems in the future, Wilson said, adding that the culture of tobacco dependence in the military will only change by getting leadership at all levels of the military to discourage tobacco use.

The study appeared in the journal Chest.