The Most Frequent Causes of Bad Indoor Air Quality
Poor air quality can result in health issues ranging from minor physical discomfort to severe health complications.
Indoor air quality, or IAQ, plays a vital role in your home's overall health and comfort. While many people assume that outdoor pollution is the main concern, the truth is that indoor air can be just as harmful—or even worse. The EPA reports that indoor air pollution is often two to five times higher than outdoor levels.
So, what causes poor air quality in home environments, and why is poor IAQ so widespread? Whether unseen pollutants or moisture-related issues, several everyday factors can degrade indoor air and affect your family's well-being.
Here's a comprehensive look at the causes of poor indoor air quality, common indoor air quality issues, and practical steps homeowners can take to address them.
Tobacco Products
Tobacco smoke is among the most harmful contributors to bad indoor air quality. Even if smoking is confined to a specific area of the house, the smoke and chemicals can travel and settle into fabrics, carpeting, and vents. This residue, often referred to as thirdhand smoke, lingers long after the cigarette is out and continues to pollute indoor air.
In homes where people smoke indoors, the air is saturated with harmful substances like carbon monoxide, formaldehyde, and benzene. These are known to trigger respiratory issues and even increase the risk of serious diseases like cancer. Reducing or eliminating indoor smoking is one of the most effective ways to improve residential IAQ.
Fuel-Burning Appliances
Many homes commonly use fireplaces, gas stoves, furnaces, and wood-burning heaters. However, these fuel-burning appliances are a significant source of indoor air pollution. When not properly vented or maintained, they release combustion byproducts like nitrogen dioxide, carbon monoxide, and fine particulate matter into your living space.
These pollutants can produce respiratory problems, eye irritation, and even long-term health complications. Ensuring all combustion appliances are properly maintained and vented is essential to controlling factors affecting indoor air quality.
High Humidity and Moisture Problems
One often overlooked indoor air quality issue is humidity. So, how can too much moisture become an indoor air quality issue? Excess humidity makes the perfect breeding ground for mold, mildew, and dust mites. These contaminants thrive in moist environments and can trigger allergies, asthma, and other respiratory problems.
Humidity levels indoors should stay between 30% and 50%. Levels above 50% may lead to lung irritation, fatigue, or even structural damage to the home. Causes of high humidity include poor ventilation, water leaks, crawlspace dampness, or improper HVAC function.
Solutions include using dehumidifiers, improving ventilation, and promptly addressing leaks. A professionally installed HVAC system with built-in humidity control can significantly improve air conditioning and IAQ in humid climates.
Asbestos
Though banned in modern construction, asbestos remains a significant source of poor IAQ in the home, especially in older properties. Asbestos fibers were used in insulation, floor tiles, roofing materials, and ceiling textures.
If these materials become disturbed—during renovations or over time—they can release microscopic fibers into the air. Inhaling asbestos can cause serious diseases, including asbestosis, lung cancer, and mesothelioma. If you think there may be asbestos in your home, contact a licensed professional to conduct testing and, if needed, remediation.
Radon
Like asbestos, radon is another hidden threat to indoor air quality. It's a naturally occurring radioactive gas that seeps through foundation cracks, basements, and crawlspaces. Invisible and odorless, radon can accumulate indoors and pose serious health risks.
Long-term radon exposure is the second leading cause of lung cancer in the U.S. after smoking. Testing your home for radon is inexpensive and straightforward. Mitigation systems are also widely available and effectively reduce radon to safe levels.
Dust and Particulate Matter
Dust is a major contributor to bad indoor air quality. It comprises dead skin cells, textile fibers, soil particles, pet hair, and more. Dust also carries allergens like pollen and dust mites, common asthma triggers.
Even worse, dust can contain volatile organic compounds (VOCs) released by furniture, paint, and cleaning products. These chemicals can cause dizziness, headaches, and long-term respiratory issues.
Regular cleaning, vacuuming with HEPA filters, and installing air purifiers can significantly reduce the dust load and improve indoor air quality.
Pet Dander
Pet dander is a constant challenge for households with animals. Dander is made of tiny flakes of skin shed by cats, dogs, and other furry pets. These particles can float through the air and become embedded in carpets, furniture, and bedding.
Dander can irritate allergies and asthma, especially in sensitive individuals. Even pets that don't shed much can release dander, contributing to poor residential IAQ.
Bathing pets regularly, using air purifiers, and cleaning surfaces frequently can help manage dander buildup.
Cleaning Products and VOCs
Many cleaning products, air fresheners, paints, and even new furniture emit volatile organic compounds (VOCs). These compounds off-gas into the air and can linger for long periods.
Common VOCs include formaldehyde, benzene, and toluene—chemicals that irritate the eyes, throat, and lungs. Over time, exposure may lead to chronic illnesses.
To improve indoor air quality, opt for low-VOC or VOC-free products, ventilate during and after use, and avoid excessive use of synthetic air fresheners or sprays.
Pesticides and Household Chemicals
Household pesticides, insect sprays, and rodent control products release chemicals that degrade air quality and can cause serious health effects. Short-term exposure can irritate the skin and eyes, while long-term exposure may impact the nervous system or hormonal balance.
Always follow manufacturer instructions when utilizing these products and ensure the space is well-ventilated. Keep them in sealed containers and dispose of them properly when no longer needed.
Poor Ventilation
Poor ventilation is one of the most powerful factors affecting indoor air quality. When a home lacks proper airflow, pollutants build up and recirculate, especially in tightly sealed or energy-efficient homes.
Poor ventilation symptoms include stale air, musty odors, increased humidity, and frequent illness or allergy symptoms. Solutions include:
Using exhaust fans in kitchens and bathrooms
Keeping HVAC systems well-maintained
Opening windows when the weather allows
Installing energy recovery ventilators (ERVs) or heat recovery ventilators (HRVs)
Improving Your Home's Indoor Air Quality
Now that you know what causes bad air quality indoors, the next step is taking action. Here are a few quick ways to improve poor residential IAQ:
Vacuum and dust regularly using HEPA-equipped vacuums
Replace HVAC filters every one to three months
Use dehumidifiers to control moisture
Add houseplants that naturally purify the air
Consider installing an air purification system
Schedule regular HVAC maintenance and duct inspections
If you have persistent or serious air quality concerns, contact a licensed HVAC company. Professionals can assess your current IAQ, recommend solutions, and help you breathe cleaner, safer air in your home.
CMB Air specializes in offering services like indoor air quality, duct fogging, duct repair and maintenance, thermostat, and iWave air purifier. No hidden charges and fees. Call (813) 447-1443 today for consultation.
