Scientists
search for ways to curb rising asthma problem
By Lauran Neergaard - The Associated Press Date:
10/16/00 22:15
CLARKSVILLE,
Md. -- 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 their 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 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 Darryl Zeldin of the National Institutes of
Health, which is spending millions searching for solutions.
Now
worsening news is spurring that hunt: About 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 to study if they help 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. According to estimates from the
National Institutes of Health, 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. The institutes
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."