Study: No Safe Level of Secondhand Smoke

When comparing the level of NNK – a carcinogen implicated in the development of lung cancer – in nonsmokers who work in restaurants that allow smoking with the level of NNK in employees of restaurants that ban smoking, researchers found that nonsmoking workers breathing secondhand smoke had significant levels of NNK.

The study also revealed that levels of NNK increased by 6 percent for each hour of work.

“There are no studies showing any safe level of exposure to this potent lung carcinogen,” said lead author Michael Stark, Ph.D. “In addition to NNK, secondhand smoke contains more than 50 other carcinogens and a host of other toxic substances that cause lung cancer, various other cancers, heart disease and lung disease.”

Stark is the principal investigator for the Multnomah County Health Department and Oregon Department of Human Services. The study appears online and in the August issue of the American Journal of Public Health.

Nonsmokers exposed to secondhand smoke have about a 20 percent increase in the risk of lung cancer – and food service workers tend to have more exposure to indoor environmental tobacco smoke than workers do in any other occupation.

Only 11 States Ban Smoking in Indoor Workplaces

Clean indoor acts already protect about 70 percent of workers from indoor environmental smoke. Yet only 11 states have clean indoor air acts that ban smoking in all indoor workplaces. In states such as Oregon, where the study took place, workplaces such as restaurants and bars have exemptions.

The researchers conclude that there is no justification for any clean-air exemptions. “Policymakers and the public need to protect the health of all nonsmoking workers by prohibiting smoking in all indoor workplaces,” Stark said.

Restaurant patrons who smoke might be in denial about the dangers of secondhand smoke, said Bruce Leistikow, M.D., an epidemiologist with the Department of Public Health Sciences at the University of California Davis Cancer Center.

“I think they underestimate the effects on themselves and thereby on others,” Leistikow said. “The risks are so high that absent tobacco-industry lobbying and disinformation, secondhand smoke exposure would already be banned in all states.”

According to OSHA spokeswoman Elaine Fraser, there has been no successful national effort at banning smoking in the workplace. However, grassroots efforts – which are strengthened by such research results – are slowly making a difference at the state and local levels.

Because of these efforts, “the anti-smoking groups believe they are having a positive effect on changing the policies of the relatively small number of businesses that do not have a smoke-free work policy,” Fraser said.