Talbot County's tough smoking law was passed to protect people from fumes streaming off other people's cigarettes. But what is the hazard? Is it death, illness or mere annoyance?
Ask the Environmental Protection Agency or the American Heart Association and you will hear that secondhand smoke not only makes people ill, but causes thousands of fatal lung cancers and heart attacks that wouldn't have occurred in a smoke-free environment.
Ask the tobacco industry, and you will hear that the EPA has engaged in pseudo-science, skewing its research to reach the politically correct conclusion that cigarette smoke is lethal even for nonsmokers. In national advertisements, cigarette companies also charge that proposed smoking bans are further examples of government intruding in the lives of individuals.
At the heart of the issue is a 1993 EPA study that branded secondhand smoke a human carcinogen, the cause of an estimated 3,000 lung cancer deaths each year among adult nonsmokers. Passive smoking also causes many adults to cough and suffer chest congestion, the agency said.
Children, too, are injured by other people's smoke, said the EPA. It held secondhand smoke responsible for 150,000 to 300,000 cases each year of bronchitis, pneumonia and other respiratory infections in children up to 18 months old. And it estimated that tobacco smoke worsens the symptoms of 200,000 to 1 million asthmatic children.
L The EPA report was a turning point in the scientific debate.
Several years earlier, the World Health Organization, the National Research Council and the U.S. Surgeon General's Office issued similar estimates of lung cancer deaths. But the EPA's estimate seemed to carry more weight, in part because it relied on a larger and more up-to-date body of research.
To many scientists, the report presented a logical bridge to the landmark 1964 report of Surgeon General Luther Terry, who warned smokers that tobacco causes cancer. Since then, scientists have found about 50 carcinogenic compounds in tobacco smoke. All but 5 percent of the 150,000 people who die each year of lung cancer are smokers.
"We don't have to test whether tobacco smoke is carcinogenic,said Dr. Douglas W. Dockery, an epidemiologist at the Harvard School of Public Health. "The question is whether there are safe levels. What these studies show is that there is no safe level."
Assessing the risk posed by secondhand smoke is complicated, in part, by the relatively small number of nonsmokers -- perhaps 7,500 a year -- who die of lung cancer. This limits the size of studies that feasibly can be done, and has rendered some studies too small to be considered statistically significant.
To solve this problem, the EPA employed a controversial technique called meta-analysis, in which data from many small studies are pooled in an effort to reach more reliable conclusions.
In the studies, researchers looked into the consequences of living with a smoking spouse. Are nonsmokers whose spouses smoke at greater risk than nonsmokers whose spouses don't? When the studies were pooled, the answer was yes. The risk of dying from lung cancer was 20 percent higher for those exposed to smoke.
"There's no question that it causes disease," said Dr. Jonathan Samet, chief of epidemiology at the Johns Hopkins School of Hygiene and Public Health and an adviser to the EPA.
"Exactly how much risk is where the controversy comes up. But another thing not to forget is that it certainly has the property of irritating the eyes and upper airway." The tobacco industry has attacked the report on several fronts.
Walker Merryman, executive vice president of the Tobacco Institute, said the EPA set out to reach a preordained conclusion that secondhand smoke is dangerous. The agency lacks the authority to regulate tobacco, he said, so it delivered new ammunition to the Occupational Safety and Health Administration. In a move to protect nonsmokers nationally, OSHA has proposed rules that would severely limit smoking in schools, factories, office buildings, restaurants, bars and other workplaces. It is holding hearings on the proposal.
Mr. Merryman also criticized the EPA for overlooking a study by the Missouri health department that, in his view, might have altered the federal agency's overall conclusions. The study was completed shortly after the panel's deadline.
The Missouri study did not find that smokers, overall, subjected their spouses to an increased risk of lung cancer. But when it looked at heavy smokers, the risk to their spouses was significantly higher.
A study published last summer in the Journal of the American Medical Association found that living with a smoking spouse raised a person's chances of developing lung cancer by 30 percent -- a greater effect than the EPA found. The research, led by Louisiana State University, is the largest single study of its kind.
The scientific debate intensified in August when the Journal of the American College of Cardiology published a study attributing 47,000 heart-disease deaths and 150,000 nonfatal heart attacks
to passive smoking. That study compared nonsmoking couples with couples in which one partner smoked.
"Whether people developed heart disease solely from passive smoking is hard to tell," said A. Judson Wells of Kennett Square, Pa., a retired Du Pont chemist who wrote the article. "I'd say what we are looking at is an additional risk factor on top of high cholesterol, high blood pressure, fat in the diet."