Raleigh, N.C. — A year after North Carolina enacted a smoking ban for most restaurants and bars, exposure to secondhand smoke by workers and patrons has been dramatically reduced, public health officials said Wednesday.

A state law that went into effect on Jan. 2 prohibits smoking at nearly all restaurants and bars. Cigar bars and private clubs are exempt from the law if they meet certain requirements.

Air-quality has improved by 89 percent in those locations since smoking was banned, according to studies by the state Division of Public Health.

In a 2008 survey, 7.8 percent of adults statewide reported being exposed to secondhand smoke daily at work. Preliminary data for the first nine months of this year shows that exposure is down to 4.3 percent of adults, officials said.

"The law is protecting North Carolinians from the health hazards of secondhand smoke, and that will have a lasting impact on the health of our citizens,” State Health Director Dr. Jeff Engel said in a statement.

Through the end of November, 1,343 complaints had been lodged against 874 establishments regarding non-compliance with the law. More than 40 percent of those complaints were filed within the first few weeks of it taking effect, officials said, noting the number of complaints has fallen each month since then.

"Compliance with the law has been excellent, with the vast majority of restaurants, bars and lodging facilities cooperating fully," Engel said.

Businesses that break the no-smoking law can be fined up to $200 per day, and smokers themselves could get burned with a $50 fine if they keep puffing after they're told to stop.

Paul M. Stone, president and chief executive of the North Carolina Restaurant and Lodging Association, said his membership is pleased with the law.

“The consensus is that this ban has had an overall positive effect on restaurants and hotels in North Carolina,” Stone said in a statement. “It also has been very well received from the public."

A survey conducted by the Gillings School of Global Public Health at the University of North Carolina at Chapel Hill found that 42 percent of people dine out more often since the ban took effect, compared with 8.3 percent who dine out less often.