Dust: A Mechanism To Fight Asthma?


Tuesday, October 17th 2000, 12:00 am
By: News On 6


CLARKSVILLE, Md. (AP) — Scientists came into little Daniel Weiss' sunny suburban home armed with a special vacuum cleaner: The 7-year-old's bed, stuffed animal collection, even under the refrigerator — no place was spared in the hunt for dust.

The dust holds clues to Daniel's asthma — traces of substances that trigger allergic reactions that send him gasping to the emergency room. In a lab, researchers wash the finely grained dust with antibodies that stain those microscopic allergens bright green, to measure how much lurks in Daniel's home.

Scientists from Maryland to Michigan are studying humble house dust to find ways to reduce allergens that leave over half of America's 17.3 million asthma sufferers wheezing. They believe the hunt could prove key to fighting the nation's worsening asthma epidemic.

``It's the idea that something about home environments is responsible for the increasing prevalence, increasing severity, of asthma,'' explained Dr. Peyton Eggleston of Baltimore's Johns Hopkins University. ``If we could change those home environments, could we reduce the asthma?''

That sounds like a no-brainer: Determine your allergies, cleanse away triggers and surely you'll feel better. Hordes of ``anti-allergy'' products claim to do just that. Yet aside from dust mite-resistant bed covers that are proven allergy aids, few of those unregulated products have been tested and some that have simply don't work, scientists say.

``We don't know the best way to remove allergens from the environment,'' and some are incredibly resistant to cleaning, says Dr. Darryl Zeldin of the National Institutes of Health, which is spending millions searching for solutions.

Now worsening news is spurring that hunt: Some 29 million Americans will suffer from asthma by 2020, predicts the nonprofit Pew Environmental Health Commission.

Already, asthma rates have more than doubled since 1980. The rise struck mostly the inner-city poor but also upper-income suburbanites. Genes haven't changed enough to explain it. So the answer must lie in our environment or lifestyle.

One popular theory: Fewer infants are exposed to enough risky germs to stimulate proper immune system development, so immune cells overreact to normally benign substances that build up in airtight, carpeted, high-humidity houses.

Smoking and secondhand smoke, air pollution, less breast-feeding and more premature babies born with delicate lungs also may play a role.

Yet although the respiratory disease kills 5,000 Americans a year and hospitalizes half a million, fewer than half the states track asthma cases to try to determine the culprits.

Whatever the underlying cause, can asthmatics keep enough allergens out of their homes day-to-day to truly reduce attacks? Scientists are testing what types of allergens dust mites, cockroaches, pet dander, mold or pollen — lurk in hundreds of homes. Then they are teaching families various cleaning methods as part of studies to see what works.

In inner-city Detroit, for example, 300 families just received free vacuum cleaners outfitted with special high-efficiency air filters known as HEPA to study if they help to keep allergens from becoming airborne.

One early disappointment: Six months after exterminating cockroaches from inner-city Baltimore homes, enough cockroach allergen still stuck to walls, floors and crevices to trigger asthma. Not even bleach eliminated it. And in Boston, professional cleaners scrubbed homes three times yet didn't get cockroach allergen below asthma-inducing levels.

Then there are dust mites. NIH estimates 22 million homes have enough of the microscopic bugs in beds to trigger asthma, a good reason to use mite-blocking mattress covers. But removing carpets is the only sure way to eradicate mites there, seldom an option for the poor or renters. NIH recently discovered that steam cleaning kills mites, but it in turn can cause asthma-inducing fungus. So Zeldin is studying possible mite-killing carpet cleaners.

Such research is vital because some allergen cleansing is expensive ``and if it isn't worth it, we shouldn't do it,'' Eggleston said.

But some simple methods can help. Take Daniel Weiss. Cat dander is his worst allergy. Yet Eggleston's testing found lots of dander in Daniel's bedroom even though he doesn't own a cat — merely playing outdoors meant he tracked in dander from neighborhood cats.

Remedies: Although Daniel isn't allergic to dust mites, it turns out mite-proof mattress covers also block cat dander from getting into the mattress. Bedding is washed in hot water instead of more energy-saving warm water. Daniel wipes clingy allergens off bedroom walls with a damp cloth weekly, and stores dust-gathering toys in a drawer. Dust-magnet drapes and rugs were banished.

Daniel hasn't had a serious asthma attack since the changes last year.

``I didn't think I'd learn that much about cleaning,'' says Daniel's mother, Amy. ``But having someone actually in your house makes a difference. ... Daniel is just so much healthier.''