Public health professors want the government to rescind exemptions to a year-old smoking ban following a study that underscores the dangers of second-hand smoke to restaurant employees.

A study by the Department of Community Medicine at the School of Public Health of Hong Kong University (HKU) compared lung function and urine samples of 204 restaurant and bar employees. The lung function of employees at establishments that still allow smoking was, on average, 6 percent lower than employees at smoke-free premises.

The study also found the level of fine particulates in exempted venues was four times higher than in non-smoking venues and 240 percent above guidelines issued by the World Health Organization for 24-hour exposure.

The study has also found that cotinine, a marker for toxic substances from tobacco smoke in the human body, was higher among employees from exempted venues.

Lam Tai-hing, director of the Public Health Research Centre at the School of Public Health, said a higher level of fine particulates typically correlates with poorer lung function.

Inhaling second-hand smoke increases the risk of health problems like lung cancer, heart attacks and strokes.

"People with poor lung function will die faster," he said.

People who have difficulty breathing after running or climbing stairs may be experiencing the early stages of lung function decline, he said.

He warned that the health of restaurant workers could be even more seriously affected in the long run if they continue to be exposed to such high level of particulates.

Hong Kong introduced a smoking ban in indoor areas of restaurants at the end of 2007 but some restaurants and bars were granted exemptions until July 1, 2009.

The exemptions should be rescinded immediately considering the harm they may cause to the health of restaurant and bar employees, said Anthony Hedley, chair professor of the Department of Community Medicine.

He also seriously objected to setting up smoking rooms in restaurants because cleaning and maintaining the rooms could jeopardize the health of workers.

Smoke permeates into carpets, curtains and furniture, he said, and the rooms are often hard to manage.

"Second-hand smoke is more poisonous than melamine or malachite green," Lam noted. "We should adopt a zero-tolerance to second-hand smoke."

The Food and Health Bureau said it has no plan to change the temporary exemption and has not reached any conclusions regarding smoking rooms.

(HK Edition 12/10/2008 page1)