A study of residents of Washington County, Md., confirms earlier suggestions that the use of gas for cooking is related to increased respiratory problems.
The Johns Hopkins University study found that the damage was far more pronounced among men than women, even though women in the largely rural county tend to spend more time in the home.
Dr. George W. Comstock, director of the Hopkins Center for Public Health Research in Hagerstown, Md., agreed that this was "further evidence" that, in many instances, "men are the weaker sex."
The study of 1,700 men and women found that nonsmoking subjects living in homes equipped with gas stoves for cooking were four times as likely to experience respiratory impairment and symptoms of breathlessness as their counterparts in homes with electric stoves.
They were about twice as likely to suffer from lung problems such as chronic coughing and production of phlegm or mucus from the respiratory tract.
These findings were concentrated among the male subjects. Nonsmoking women appeared to show a similiar tendency, but in scientific terms the evidence was not "statistically significant," Comstock said.
It is not known why there would be a sex difference, but the Hopkins team speculated that perhaps it stemmed from the historically greater exposure of women to pollutants in the home, dating back to cave-dwelling times. They suggested that natural selection "might have resulted in women being less susceptible to domestic smoke and fumes."
Whatever the reason, Hopkins professor Harold Menkes noted, the latest findings agree with other research involving humans and animals that has found physical differences in the response of the lungs of males and females to environmental insult. He said that the effects of cigarette smoking in terms of chronic airway obstruction are less noticeable in women.
The health hazards of gas stoves have been studied by other researchers, with some disagreement about the effects. While studies of children in England and Scotland and in six U.S. cities have found more respiratory illness in those living in homes with gas stoves, this was not found in studies in Columbus, Ohio, and Long Island, New York.
Comstock acknowledged that the link was difficult to prove, but said it would be "prudent to vent gas stoves with a fan or opening which takes the fumes to the outside." The primary suspect is thought to be nitrogen oxides resulting from the combustion of natural gas.
Comstock said that the Maryland center has found no link between respiratory problems and gas heating, presumbably because of better ventilation.
In addition to studying the effects of gas stoves, the latest Maryland study also looked at the effects of "passive smoking," or exposure of nonsmokers to cigarette smoke in the home. The study did not find any statistically significant evidence to suggest that adult nonsmokers who live with smokers face greater respiratory risks.
The nonsmokers did show some lung impairment, said Comstock, who said that caution is warranted because of other studies' findings.