Atlanta, Georgia (CNN) -- If you're trying to find a job these days, it might help to get rid of your cigarette habit.
A hospital in the Atlanta suburbs is the latest employer nationwide that is refusing to hire smokers.
Gwinnett Medical Center instituted the policy July 1, but other hospitals, including Cleveland Medical Center in Ohio, also have the policy. The Scotts Miracle-Gro Co., the lawn-care giant, hasn't hired smokers since 2006.
Steve Nadeau, Gwinnett Medical Center senior vice president of human resources, said the policy is an extension of their efforts to promote better health.
"We believe it's just supporting good health, we're a health care provider," Nadeau said. "We've had a smoking prohibition inside ... and outside and it's just really kind of a natural evolution," he said. Existing employees who smoke will not be fired.
The medical center offers smoking cessation classes and has plans to revamp signage throughout their facility.
Nadeau said the response from focus groups and employees has been "good."
"We hope it won't mean we will lose good employees, but I have no doubt there are going to be folks we won't be able to get. From a policy standpoint it's the right direction for us," he said.
But Dr. Michael Siegel, a Boston University professor of public health, said the policy is an invasion of privacy and keeps qualified medical professionals away.
"From personal experience as a physician, some of the best nurses happen to be smokers," Siegel said. "Are you willing to hire staff that is not the best qualified simply because you're trying to make this point about how bad smoking is?"
Siegel, who is quick to note he supports smoke-free workplaces, said "regulating someone's private behavior in their own home ... really represents employment discrimination and has nothing to do with qualifications for the job. If the hospital is so concerned about health, you can make the exact same argument about overweight people."
The rate of smoking among physicians is low, Siegel said. But the rate among nurses is more than 20 percent -- higher than the general population.
"This policy will result in the hospital not hiring the most qualified people. You're eliminating 20 percent of the population," he said.
The National Institute of Business Management's website reports that as of 2007, laws in 30 states and the District of Columbia prohibit employers from discriminating against employees or applicants based on the person's off-duty use of tobacco.
Gary Nolan, a spokesman for Citizens Freedom Alliance: The Smoker's Club, is annoyed by the ban but supports private businesses' right to hire anyone they want.
"If you go in for heart surgery, do you really care if your surgeon smokes?" Nolan said.
But in Ohio, Cleveland Clinic officials say the hiring ban in place since 2007 is a success.
"It was a policy directive by our CEO (Dr. Delos Cosgrove) who wanted to fully enhance the idea of a health institution being what it says it is -- a healthy place to work," said Dr. Paul Terpeluk, Medical Director of Employee Health. "He felt health care workers shouldn't be smokers."
Since the policy began, 250 potential employees have failed the drug test for nicotine. Cleveland hires 5,000 employees a year, Terpeluk said. Those who fail the test can reapply in 90 days.
"It does make sense if you're a health care institution, you want everyone to be as healthy as possible," he said, adding that employees are also given incentives to lose weight.
Hospital officials don't think the policy affects the quality of employees they hire.
"Cleveland Clinic is a center of excellence and when people apply here they really want to come work at this institution. We don't want smokers. It's not in line with our caregiver mission," he said.
Industries outside health care have also dabbled in banning smokers from employment. Scotts Miracle-Gro not only bans smokers from employment, it fires employees who smoke. Jim King, senior vice president of corporate affairs, said the self-insured company decided smokers' heath care costs were too high.
"Like everybody else, we were looking at wellness and health care and the drivers of health care costs," King said. Before the policy, 30 percent of Scotts' 8,000 employees smoked. Now that number is less than 7 percent.
