They believe the hunt could prove key to fighting the nation's worsening asthma epidemic. 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. Already, asthma rates have more than doubled since 1980. Genes haven't changed enough to explain it. So the answer must lie in our environment or lifestyle.
Dust mites and roaches love high-humidity homes.
Keep pets out of bedrooms. 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. Then they are teaching families various cleaning methods as part of studies to see what works.