Examining the Childhood Asthma Epidemic: Part 4

Why Are Asthma Rates Rising?

Since genetics haven’t changed dramatically over the past 20 years, increases are apparently environmentally caused. Dr. Redding is a proponent of the “hygiene theory.” Immune systems develop in the first two years of a child’s life as he or she fights a variety of infections. In developed countries, our environment may be so “hygienic” that there aren’t enough infections to “rev up” the immune system, which then becomes overreactive to allergens and irritants, Redding explains. He points out that asthma rates are lower if babies are exposed to pets, farm animals, siblings or other children.

Talk to other parents whose children have asthma.

“If you fight infections, whether respiratory or gastro-intestinal, you’ll get less asthma,”
Redding says. But, once children develop asthma, they may have to avoid infections and animals.

Asthma rates are lower in developing countries. Rates used to be low in communist East Germany, where health care was relatively primitive. They caught up with higher rates in West Germany after the countries were reunited.

In the same vein, the National Institute of Environmental Health Sciences (NIEHS) reports that increases in asthma cases in developed countries have occurred despite the decline of serious pulmonary diseases, such as tuberculosis and pneumonia. Researchers hypothesize that underutilized immune systems are overreacting to lesser threats.

NIEHS researchers speculate that improvements in outdoor air quality are offset by the fact that children are spending more time indoors exposed to allergens and pollutants trapped in carpets and other surfaces.

Scientists have also been grappling with the fact that inner-city children, especially African-Americans, suffer higher rates of asthma and have three times the asthma mortality rate. The ALA attributes the discrepancy to limited access to health care, poor asthma education and undermedication.

The Inner-City Asthma Study, commissioned by the NIEHS in partnership with the National Institute of Allergy and Infectious Diseases, looked at seven major U.S. cities. Researchers found that children genetically predisposed to asthma were living in allergen-loaded environments:

  • 77 percent lived in homes with evidence of roaches.

  • 70 percent had homes with significant dampness and mold.

  • 47 percent lived with at least one smoker.

  • 71 percent of families cooked with gas (a source of nitrogen dioxide).

“In the East and South, the main problem is cockroaches. In the rest of the country, it’s dust mites and smoking,” Redding points out. “A lot of the problem is due to the chaos of poverty: it’s tough to do careful management when the rest of your life is in turmoil.”

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