As states and localities debate smoking bans, U.S. Surgeon General Richard H. Carmona declared yesterday that secondhand smoke triggers diseases that include lung cancer and sudden infant death syndrome -- and that no level is safe.
"Science has proven that there is no risk-free level of exposure to secondhand smoke," Carmona said at a Washington news conference, summing up a 709-page report that is the surgeon general's office's first assessment of the risks in two decades.
While former Surgeon General C. Everett Koop said in 1986 that exposure to other people's tobacco smoke can trigger lung cancer, Carmona added several other diseases. Included are heart disease, asthma, ear infections and SIDS.
"The science is clear," Carmona said. "Secondhand smoking is not a mere annoyance. It's a premature death hazard."
Pulling together what its authors called the best available research, the new report estimates that secondhand smoke increases a nonsmoker's risk of heart disease by 25 percent to 30 percent and lung cancer by 20 percent to 30 percent.
The California Environmental Protection Agency estimated last year that passive smoking is responsible for 3,400 excess deaths from lung cancer annually in the United States, as well as 46,000 deaths from heart disease and 430 from SIDS.
Passive smoking is also responsible for as many as 71,900 low-birthweight or preterm deliveries annually and about 202,000 flare-ups of childhood asthma, according to the California report.
"The health effects of secondhand smoke exposure are more pervasive than we previously thought," Carmona said in a statement.
The news was not all bad. The surgeon general said that levels of cotinine -- a biological marker for secondhand smoke -- in nonsmokers has fallen by 70 percent since the late 1980s. Similarly, the proportion of nonsmokers with detectable cotinine has fallen from 88 percent to 43 percent over that period.
Carmona said he didn't want to make policy for localities but stated flatly that nonsmokers are only protected in buildings that are absolutely smoke-free. Separating smokers and nonsmokers is not effective, the report said, and air-handling systems are incapable of eliminating carcinogens and other harmful components of tobacco smoke.
"This report should be a wake-up call for lawmakers to enact comprehensive clean indoor air laws that prohibit smoking in all indoor public places and workplaces," Dr. Ron Davis, president-elect of the American Medical Association, said in a statement.
Maryland anti-smoking advocates used the report's release to express their hopes for a state or Baltimore City smoking ban in restaurants and bars. The study, they said, should compel action on smoking prohibitions that have languished at the State House and City Hall.
"All Marylanders have a right to breathe clean air in the workplace," said Kari Appler, director of the Smoke Free Maryland Coalition, which has lobbied in favor of a ban.
But lawmakers have failed to embrace smoking restrictions in the past four sessions, and Gov. Robert L. Ehrlich Jr. has said he would veto a ban. In Baltimore, a proposed ban has stalled in the City Council since March, though members who support the measure are trying to revive it.
Councilman Robert W. Curran said he will schedule a hearing for his bill this fall. Curran and Councilman Kenneth N. Harris Sr. -- the other sponsor of the city bill -- joined advocates at a news conference yesterday to argue that the city has fallen behind the national trend on the issue.
"We're becoming known as the ashtray of the Northeast, and that's totally unacceptable," said Harris, noting that smoking bans have been approved in Philadelphia, New York and Washington.
The likelihood of a smoking ban being approved in an election year is slim, many have said. Mayor Martin O'Malley, the expected Democratic nominee for governor, has said he prefers a statewide smoking ban to a local one.
The Baltimore proposal was modeled after California's statewide law. Four Maryland counties -- Howard, Montgomery, Prince George's and Talbot -- have passed bans for restaurants and bars.
Although the Maryland Restaurant Association has opposed smoking bans, a Kentucky restaurateur at yesterday's news conference in Washington presented a different view.
Mike Scanlon, the vice mayor of Lexington, Ky., who also runs a company that operates 85 Applebee's and Johnny Carino's restaurants across the country, described no-smoking policies as good for business. Customers don't have to wait to be seated in nonsmoking sections, and employees in his franchises are healthier because they don't have to involuntarily inhale smoke.
"If corporations understood that their servers were getting hurt, they'd stop doing it," said Scanlon, who also helped push through a smoking ban in Lexington.
Scientists who compiled the surgeon general's report did not conduct new studies but drew from what they considered the best available research.
Dr. Jonathan Samet, a Johns Hopkins University epidemiologist who served as the report's senior scientific editor, said a person's risk of various health effects depends in part on the degree of exposure. Someone living under the same roof as a smoker, for instance, faces a higher risk of lung cancer than someone who drinks occasionally at a bar where others smoke.
"A little exposure leads to some risk, more leads to more," said Samet, chairman of epidemiology at the Johns Hopkins Bloomberg School of Public Health. "But any exposure can lead to the DNA damage that initiates cancer."
Much of the key evidence stemmed from studies of nonsmokers who were married to smokers, finding that their disease rates compared unfavorably to those of nonsmoking couples.
Also, Samet pointed out that a single encounter with smoke can throw an asthmatic child into a life-threatening attack.
Scientists do not know the mechanism by which environmental smoke can raise an infant's risk of dying suddenly. But studies have shown that the odds increase when a mother smokes during pregnancy or if either parent smokes afterward.
Protecting children from secondhand smoke is one of the principal goals of Brenda Bell Caffee, who runs a research institute that focuses on health disparities in Hattiesburg, Miss. Under a grant from the Environmental Protection Agency, she teaches black women about the hazards of exposing their children to smoke.
"I'm saying that your child is going to do a whole lot better if you don't let them go around people who smoke," she said at the news conference.