The incidence of asthma and numerous allergies, reports the US Centers for Disease Control and Prevention has been steadily increasing in just the last couple of decades. It's no surprise that there's an environmental correlation there, for the last couple of decades have also seen an increase in "closed-envelope" buildings that are tightly insulated and feature airtight windows and doors. That closed-in construction is great for energy efficiency, but it gives a fine harbor for one of the main culprits in allergies such as hay fever and assorted respiratory ailments, including asthma.

 

The dreaded dust mite

That culprit is the tiniest of spiders, the dust mite. Its two-part name, Dermatophagoides farinae, is suggestive of what it does: dust mites live on sloughed-off skin, and humans do shed a lot of it, as much as 1.5 pounds each year. Dust mites, which look like some sort of extraterrestrial monster under a microscope, have a habit of hiding just where that castaway skin is most abundant: mattresses, naturally, but also hard-to-get-to corners of the bedroom and other parts of the house (and of course, our bedclothes).

Those little tufts floating around under the bed that we cutely call "dust bunnies?" They're full of our skin, pet hair, dust, and of course, dust mites enjoying the feast. To compound the unpleasantry, it's not the mites themselves that are the cause of allergies, but their microscopic poop.

Secretions on animal fur (particularly a cat's), and tiny pollen grains that seep into the house when plants are in bloom, create a heady brew about which every allergy sufferer can tell you tales of woe.

The bedroom is probably the scariest room in the house. "I am constantly amazed at the particles I find in bedroom air," wrote organic chemist Jeffrey C. May in collaboration with his wife and air-quality technician Connie L. May in "My House Is Killing Me! A Complete Guide to a Healthier Indoor Environment."

Airing out the mattress is a good start to taming those troublesome particles, as is removing the carpets and giving them a good beating with a fireplace poker or baseball bat, which can shake out carpet beetle dung and other nasty things. Pillows, whether on the bed or couch, are also a paradise for mites, so wash and air-dry them while you're at it.

Getting rid of mold and dust

Other components of dust are also implicated in various allergies. Now we know, thanks to satellite images, that dust floats around the world, picking up pollutants and even radioactive isotopes as it moseys along. That's why it's important to take the time to dust the furniture, too, as well as hard-to-see places like the tops of doors, refrigerators, cabinets and the like.

The final step is to vacuum every vacuumable inch of the house, including the walls and ceiling. It's no surprise, as Joseph A. Amato writes in his book "Dust: A History of the Small and Invisible," that some of the first vacuum cleaners were made by people who suffered from allergies and asthma: Melville R. Bissell had a fierce allergy to straw, and James Murray Spangler -- who created the company later bought and renamed by William H. Hoover -- was a severely asthmatic janitor.

Most high-end modern vacuums, as the Mays' book explains, come with HEPA filters filter out many kinds of allergens. They aren't cheap, but they do capture all the large particles and 99.97 percent of those suspended in the air as you move along.

Cleaning and clearing the closet

Be sure to get inside your closets while you're vacuuming. While you're in there, you can, if so inclined, steal a page from Marie Kondo and declutter, getting rid of things you no longer need, want or cherish. You might also want to lay in fresh blocks or discs of cedar wood to deter the moths that seem to pop up every spring.

There's no end of good, science-rooted reasons to take the time to give your home a deep cleaning—and since COVID has made homebodies of us, there's no time like now, the beginning of spring, to do so. Your respiratory system will thank you.