THURSDAY, March 7, 2002 (HealthDayNews) -- The cat's out of the bag -- the vacuum bag, that is.
British scientists report that vacuuming in households with cats, even with modern, filter-equipped models, sends dust flying and feline allergen levels soaring.
The study is the first of its kind to measure personal inhaled allergen exposure in a real-world setting. It challenges the notion that frequent vacuuming reduces pet allergen levels in homes, and casts doubt on whether vacuum designs touted for specific air-filtration capabilities are truly effective at reducing household allergens.
The findings were presented this week in New York at the annual meeting of the American Academy of Allergy, Asthma and Immunology.
Researchers from Wythenshawe Hospital in Manchester compared seven kinds of vacuum cleaners: four new types fitted with high efficiency particulate air (HEPA) filters, a cyclone-design vacuum cleaner, a water reservoir model, and an old model. They were tested in six different homes with cats.
Study volunteers measured personal cat allergen exposure before vacuuming using a device called an intranasal air sampler, then repeated the procedure while one person vacuumed. The cats (not surprisingly) were out of the room while the vacuums were running.
Senior investigator Dr. Adnan Custovic and his colleagues found that allergen exposure was 3.7 times higher during vacuuming than before the room was cleaned. The type of vacuum, including those with HEPA filters, made no difference.
Next, the vacuum cleaners were loaded with dust containing 36 milligrams of cat allergen. Exposure was measured while in a sterile room with the machine. They found the cyclone and the older vacuum cleaner leaked allergens, while the others didn't.
Finally, the researchers measured exposure while the vacuum cleaner was emptied, and found that both the person emptying the bag and bystanders were exposed to cat allergens.
Vacuum manufacturers make "some interesting claims which have never been substantiated," Custovic says.
Calls to vacuum makers Hoover, Bissell, Royal Appliances Manufacturing Co. (the makers of Dirt Devil vacuums), and Oreck Corp. were not returned.
Custovic adds that while it may be painful for pet owners, the best remedy is to get rid of the cat.
"If you're cat-allergic, if you have a cat, and if you have severe asthma that is driven by that cat allergy, then there's only one option," Custovic says.
The results are "a bit of a surprise," says Dr. Richard Honsinger, a clinical professor of medicine at the University of New Mexico. "Because we've always said to patients that if you have a better vacuum cleaner that doesn't put out as much dust, you won't put as much cat allergens or things in the air."
On the other hand, Honsinger says, the sweeping motion of vacuuming can easily disturb dust and allergens on the floor.
"These particles are exceeding small," Honsinger says, adding they remain in the air long after the vacuum has been put away.
Honsinger says that much-hyped HEPA filters, which were originally designed to collect asbestos during industrial cleaning, are porous enough to allow the tiny allergen particles through.
"Before we had fancier vacuum cleaners, we've always told people [to] wet-mop instead of vacuum -- have bare floors and wet-mop," Honsinger says. "I guess the old adage is probably true."
So, what can cat owners do?
"Our first advice is: No cats," Honsinger says. However, many cat owners refuse to give up their pets in spite of their allergies. "Our second advice is that if you can wash things, it's better than trying to stir them up."
"The best advice is still steam-clean your carpet, mop your floor," Honsinger says.
However, Custovic says cat allergens are very resistant to heat, making steam cleaning useless for fighting these allergens.
What To Do
Hoover publishes this information about their vacuums' air filtration systems. You can also check out this glossary of respiratory protection terms from the Occupational Safety and Health Administration.
Can't bear to part with kitty? Find advice about living with pet allergies from the Animal Assistance League or the Atlanta Allergy & Asthma Clinic.
