March 5, 2001 -- Cases of asthma, a common but potentially fatal respiratory ailment, are on the rise in children. But experts say that you may be able to prevent your child from developing the disease by eliminating some causes of respiratory distress in your home.
Indeed, a staggering half a million U.S. children under age 6 could be spared the debilitating illness by reducing risk factors found in many homes, including tobacco smoke, pets, and gas stoves, according to a report published in the March issue of Pediatrics.
In addition to reducing asthma in children by 39%, removing tobacco smoke and allergy-causing factors could save as much as $402 million annually in asthma-related medical costs in the U.S., according to lead study author Bruce Lanphear, MD, MPH, and his colleagues from the University of Rochester (NY) School of Medicine, the American Academy of Pediatrics, and the University of California, Davis.
"People don't understand housing as a public health issue," Lanphear says. "Very little is done to eliminate health risks in the home except for traditional things like smoke detectors."
The American Academy of Allergy, Asthma, and Immunology (AAAAI) estimates that almost 5 million youngsters under the age of 18, including 1.3 million under age 5, suffer from asthma. The group also estimates that the disease results in nearly 3 million trips to a doctor and 200,000 hospitalizations each year. Approximately 150 U.S. children under age 15 die from asthma each year, with more than 5,000 deaths occurring annually in people of all ages.
Lanphear and his team studied almost 8,300 youngsters under age 6 who participated in the National Health and Nutrition Examination Survey III from 1988 to 1994. Overall, the researchers found that about 6% of the children had asthma diagnosed by a doctor.
The children in the survey were 24 times more likely to have asthma if they had a history of allergies to pets, Lanphear says. Dogs in the house were the cause of 140,000 cases of asthma in those surveyed. Cats were not studied in this investigation, but experts say they can cause even more of a problem because their saliva and skin flakes stick to upholstery and carpeting.
In addition, almost 180,000 asthma cases were due to environmental tobacco smoke, and use of a gas stove accounted for 59,000, the scientists report.
Children most at risk from these residential factors are those with a history of allergies and those whose families have a history of asthma, especially if the mother had the ailment, Lanphear says.
"Cigarette smoke is the overwhelming cause of residential exposure-caused asthma," he warns. "But very little is done to improve ventilation in the house. Small children spend 90% of their time in the house. Parents need to quit smoking or at least provide proper ventilation."
Maynard Dyson, MD, a pediatric pulmonary physician at Cook Children's Medical Center in Fort Worth, Texas, reiterates Lanphear's warning about the exposure risks to tobacco smoke, indoor pets, and open flames from gas cooking. He also says that a serious problem not studied in Lanphear's report is dust mites -- microscopic animals that live in upholstery, carpeting, and bedding. These tiny creatures feed on flakes of skin shed by people and pets.
"Dust mites need something to feed on, so it's best to have flooring other than carpet. They don't do well on tile," Dyson tells WebMD. "They also need humidity. In very dry climates, they have very little problem with dust mites."
Dyson and Lanphear say that eliminating carpeting, adding a dehumidifier, keeping pets out of the house, and keeping the house clean -- including washing bedding frequently in hot water -- will help prevent asthma.
"The most cost-effective way to get rid of dust mites is plastic coverings on mattresses and pillows," Dyson says. He also recommends putting air-cleaning filters on your central heating and air conditioning system. If the house is equipped with baseboard heat, he says freestanding filtering units will help.
Mold and mildew also can trigger allergies and asthma, he says. The first step to ridding the house of this disease-causing problem is to get rid of any source of excess moisture; then you can remove the mold and mildew. This may even entail removing and replacing wall materials.
Lanphear says a great deal more study is necessary to find ways to improve the household environment's effect on asthma. "Housing is an emerging public health problem," he says. "We need to think about environmental controls to prevent asthma. We spend millions looking at occupational health issues and on studying the human genome; we need to do the same with housing and treat it as a public health issue."