Discovering the causes of poor indoor air quality is the first step in creating a healthful home. For years we have cleaned, dusted and vacuumed our houses but what about the part of our homes that we don’t see, yet breathe into our lungs thousands of times every day. Indoor air is a fundamental part of how our homes affect us, but it’s often overlooked and misunderstood.
Americans spend up to 90% of their time indoors. According to the Environmental Protection Agency (EPA), indoor air can actually be more polluted than outdoor air. The consequence of spending so much time indoors and breathing polluted air can be seen in the increase of asthma and chronic respiratory disease among Americans. What makes indoor air quality (IAQ) most difficult to understand is that it can’t be easily or accurately tested. There’s a vast world of contaminants to test for, and for most of them, there aren’t clear exposure limits to compare against. Plus, testing is just a snapshot of a home’s condition. Instead, looking at the sources of pollutants and the way they enter the living space is the best way to determine if your house is as healthful as it can be. So lets take a look a the contributing factors in indoor air pollution and then we can address a holistic solution to the problem. Let’s begin with particulates.
Particulates are the tiny particles floating around in the air. Some of it settles out on the furniture and we call it dust. But dust is the generic word for particulate that has been airborne and is now collecting on our furniture and furnishings. The real problem is the stuff that hasn’t settled yet. You don’t have to read about allergies to know that larger particulates get stopped by our natural filtration processes; like the tiny hairs in our nose, lungs and mucous membranes. The tiny particulates are the greater concern because they go deep down inside our lungs and stay there. These can only be seen on a bright morning in the shaft of sunlight that pours through our windows. The stuff is floating everywhere in our indoor environment. Scientists tell us that dust is a composite of a lot of materials. Pollen, pet dander, dirt, carpet fibers and dead skin cells from our own bodies make up dust. However, about 80% of the stuff you see in that shaft of light is actually human dead skin cells.
The reason particulates are considered an indoor air pollutant has to do not only with its prevalence in our environments, but its ability to carry other contaminants. Much of it is microscopic, but it is large enough to carry even smaller things like bacteria, mold, viruses, and other biological contaminants. Think about how viruses and other bio-contaminants are transmitted. They ride on the particulate, living long enough for us to suck them down into our lungs. So particulates play a huge part in the transmission of all kinds of biological contaminants. It’s not just the particulate but it’s what it carries.
It has been known for a long time that household dust is a major cause of allergic symptoms and disease. Studies have shown that allergic sensitization to the house dust mite is the most common cause of allergy in asthmatics. Many years ago, the dust mites were found mainly in birds nests, but now they have found their way into warm, snug and humid houses. In fact, dust mites were first recognized in bedding back in the 1920’s but it took another 40 years to establish their role as a source of allergens and a trigger for asthma.
But dust mites themselves are living creatures. They are microscopic, eight –legged scavengers that live in the common household dust, mainly feeding off the tiny flakes of our shedding skin. They are constantly breeding in our carpets, bed linens, curtains and furniture. They are a natural and perhaps necessary part of the food chain. As scavengers, they go about their daily task of cleaning up our environment at least on their terms. Each dust mite typically lives about 2 to 4 months and produces about 20 droppings per day. It is these droppings which contain the allergens that prove to be such a nuisance and distress to allergy sufferers. It is estimated that an ounce of dust can be host to 10-20,000 of these creatures. Consider that in a single year, the typical home can generate up to 30-40 pounds of dust. Do the math and you realize that the typical home is occupied by dust mites in the millions, defecating everywhere!
Imagine your average bed with 10,000 of these creatures making up their beds. Your only reassurance is that they do not bite, sting or transmit disease, so they do not really pose any threat except to people who are allergic to their fecal matter.
So how do we get rid of or control these unwanted quests in our homes. Here are ten tips for controlling dust mites.
- Encase mattresses and pillows with dust proof or allergen impenetrable covers.
- Use a dehumidifier or air conditioner in the summer to maintain lower relative humidity. Dust mites thrive in moist air.
- Wash all bedding / blankets in hot water once a week. This will kill the critters.
- Wash all blinds and curtains regularly.
- Replace wool and feather-stuffed bedding materials with synthetics.
- Keep only the washable stuffed animals and toys.
- Choose hard flooring in preference to carpets, especially in bedrooms.
- Use a damp mop or rag for dusting. Dry cloths only stir up the mite allergens.
- Vacuum only with good ventilation. Central vacuums which vent to the outdoors are preferred. Portable vacuum cleaners should have highly rated filters.
- Use an efficient air filtration / purification system.
Hopefully we have had some fun with this and grown in our understanding of what can be contributing to allergies.
Steve Sheffield is a full time home inspector with certifications through ASHI, American Society of Home Inspectors, and the IRC, International Residential Building Code. He has completed over 1500 inspections since starting Hometown Inspection Services, LLC eight years ago. Prior to starting Hometown Inspection he was in the lumber / construction supply business for over 30 years. He can be reached at: email@example.com or 770-789-1463.