Homeowners Should Watch for Elevated Radon Levels, Mold, and Combustion Gases

Do you know how clean the air is in your North Carolina home? Indoor air quality (IAQ) is a growing concern in the Tar Heel state and across the country, with many homes harboring contaminants such as bacteria, mold, formaldehyde, ozone and dangerous gases that pose health risks. Radon is a particular challenge here because the state’s soil and geology can naturally release the gas into homes.

North Carolina’s geography – from the mountains near Asheville to the coast by Wilmington – combined with a mix of old and new homes makes indoor air quality a priority for families across the state. Poor air quality contributes to allergies, breathing issues, headaches, and fatigue.

With the right mix of ventilation, air purification, and moisture control, North Carolina homeowners can reduce indoor pollutants and create a healthier environment for their families.

Why Indoor Air Quality Matters in NC

Factors that can affect the air quality in North Carolina homes include:

• Humidity: Areas along the coast and in low-lying parts of North Carolina, including the Outer Banks and Greenville, tend to have higher humidity, making mold more likely in homes. This is especially common in areas like basements and crawlspaces with poor ventilation or moisture. Mold can release harmful spores that worsen allergies, asthma, and other respiratory issues. 
• Well-sealed homes: Modern or renovated homes in cities such as Charlotte and Raleigh, NC, often have tighter construction to prevent heating and cooling loss and lower energy bills. However, this tends to trap indoor pollutants such as VOCs, dust, and allergens, leading to higher exposure levels, according to the North Carolina Department of Health and Human Services.
• Wood-burning stoves and fireplaces: Across North Carolina, especially in the mountains and Piedmont region, common heating sources such as gas fireplaces may release smoke, particulate matter, and carbon monoxide indoors if they aren’t properly vented and maintained.
• Radon: High radon levels have been detected in buildings in more than three-quarters of North Carolina’s counties.
• New homes: In rapidly growing North Carolina cities like Charlotte, Raleigh, and Asheville, new home construction can sometimes lead to higher levels of indoor air contaminants. Fresh building materials, paints, and adhesives can off-gas chemicals, while dust and debris from construction may temporarily affect both the new home and nearby houses.

Common Indoor Air Contaminants in NC Homes

North Carolinians should be aware of these potential indoor air risks and take the appropriate steps to keep their loved ones safe and healthy.

Radon

Radon isn’t as widely recognized as other gases among NC homeowners, but it can be extremely harmful at high levels. It’s a colorless, odorless gas that’s impossible to detect without testing. Radon enters homes through the natural decay of uranium in the soil and rock.

Radon is the leading cause of lung cancer for non-smokers. Each year, about 21,000 people in the U.S. and around 450 in North Carolina die from radon-related lung cancer.

The only way to know how much radon is in a home or building is to test for it. The North Carolina Radon Program recommends testing all homes every two years.

Data from the Centers for Disease Control and Prevention (CDC) shows that 77 of North Carolina’s 100 counties have at least one building with radon levels above the EPA action level of 4 pCi/L, meaning many homes may have concentrations high enough to warrant mitigation. Counties like Buncombe, Henderson, Transylvania, Mitchell, Watauga, Rockingham, Cherokee, and Alleghany are considered “Zone 1” (red), meaning they have the highest predicted indoor radon potential in North Carolina.

Mold and Moisture-related Problems

Mold is a common concern in North Carolina, especially in areas like Charlotte and Wilmington, with increased humidity, heavy rainfall, or poor ventilation. Homes in coastal, low-lying, and mountainous regions are particularly prone to mold, as moisture from leaks, condensation, or flooding creates the perfect environment for growth. Mold also damages homes, including wood, drywall, and other materials.

Exposure to mold occurs when tiny airborne particles called spores are inhaled. While most everyday exposure is harmless, increased concentrations may lead to allergic reactions like runny nose and sneezing, or asthma attacks such as wheezing, chest tightness, and coughing. Certain molds – especially Stachybotrys (black mold), Aspergillus, and Penicillium – can release chemicals called mycotoxins, which may have toxic effects when exposure is significant.

Homeowners can reduce mold exposure through proper ventilation, humidity control, cleaning up leaks, and regular cleaning. Air purification systems can also neutralize mold spores and other airborne particles.

Volatile Organic Compounds (VOCs) & Other Chemicals

Volatile organic compounds (VOCs) are chemicals that are released by everyday products like paints, cleaners, building materials, and new furniture. These compounds collect indoors, often at higher levels than outside. While VOCs are the primary concern, other chemicals such as pesticides and solvents may also enter homes.

Exposure to airborne chemicals is linked to irritation, headaches, dizziness, or nausea. Long-term exposure has been linked to more serious health effects, including damage to the liver or nervous system. Formaldehyde, one of the most common VOCs, is found in pressed-wood furniture, cabinets, fabrics, and tobacco smoke. It can increase cancer risk.

Homeowners in large cities such as Charlotte, Fayetteville, and Durham can reduce VOC exposure by choosing low-VOC products, improving ventilation when painting or cleaning, and following product directions carefully. Air purification devices also remove VOCs and other airborne chemicals from homes.

Combustion Gases (CO, NO₂)

Carbon monoxide is a dangerous gas that’s hard to detect because it’s colorless, odorless, and tasteless. Common sources include natural gas appliances, heaters, and power tools, according to the North Carolina Department of Health and Human Services. Oil, kerosene, coal, gasoline, wood, and liquified petroleum can also produce CO. Leaks occur when fuel-burning equipment is poorly vented, malfunctioning, or used in enclosed spaces.

Common monoxide poisoning may cause shortness of breath, headache, chest pain, nausea, dizziness, and loss of consciousness. According to the CDC, more than 400 people die each year from CO exposure.

If you suspect high levels of CO, leave the house immediately and call 911 or our local utility provider. Installing carbon monoxide detectors on every floor of your home and outside all sleeping areas alerts you to its presence.

Meanwhile, nitrogen dioxide (NO₂) is also a threat in some North Carolina homes, especially where gas stoves, heaters, or other fuel-burning appliances are used without proper ventilation. It’s produced during combustion, and when levels build up indoors, it can irritate the lungs and worsen asthma, particularly in children.

Ozone

Ozone pollution can be an issue in parts of North Carolina, especially in the warmer months when sunlight, heat, and emissions from cars or industrial work create smog. Cities like Charlotte, Raleigh, and some mountain areas can see ozone levels spike at times. Since homes pull in outdoor air, some of that ozone can drift inside, which might irritate lungs or trigger asthma and allergies.

You can help keep your indoor air cleaner by keeping windows closed on high-ozone days, limiting outdoor activity, and running your HVAC or air purification system. Avoid air purifiers that generate ozone, as they can actually make indoor air quality worse. Regular ventilation and filtration can protect everyone in your home, especially kids, older adults, or anyone with breathing issues.

Signs of Poor Indoor Air Quality in NC Homes

Most indoor contaminants and pollutants in North Carolina homes are invisible and difficult to detect. These signs help determine if your home’s air is at risk.

Health Issues

Are you frequently under the weather? Contaminants such as dust mites, mold, pet dander, tobacco smoke, and combustion gases can make you sick. People who live in these conditions are more likely to experience frequent or severe asthma attacks and other issues such as headaches, congestion, coughing, or skin and eye irritation.

Environmental Signals

Your home may reveal clues about its air quality. Musty odors, stale air, dusty conditions, or condensation on windows often mean poor ventilation and increased moisture. These signs may indicate larger air quality problems that need to be addressed.

Unusual or Persistent Odors

Chemical odors from paints, cleaners, or off-gassing materials increase VOC levels. These smells tend to hang around longer when humidity is high, which makes irritation worse for people who are sensitive.

Poor HVAC Performance

Rooms that never seem to heat or cool properly, or vents with visible dirt buildup, may suggest ventilation or filtration problems affecting overall air quality. When your system isn’t running well, it can recirculate dust, allergens, and pollutants instead of removing them.

How to Improve Indoor Air Quality in NC Homes

Whether you live in cities like Charlotte or Raleigh, or near the mountains around Asheville and Boone, you can protect your family’s health by taking the following steps:

Testing & Assessment

• Test for radon using kits, or hire a radon professional. Click here for tips on how to use a radon detector or where to find qualified testers in North Carolina.
• Hire an indoor air quality inspector to assess for mold, VOCs, combustion gases, and other hidden pollutants that aren’t obvious to homeowners. Issues like these are difficult and hazardous to diagnose on your own. A professional has the tools and know-how to pinpoint problems safely and recommend the right fixes.
• Install carbon monoxide detectors. They typically cost between $20 and $50 and can be found at most home improvement stores or online.

Ventilation & Air Circulation

• Use exhaust fans in spaces with high humidity such as bathrooms and kitchens.
• Run your HVAC on “circulate” mode to reduce stale air build-up. This setting keeps air moving through your home’s ducts even when heating or cooling isn’t actively running, helping to filter out dust, allergens, and other pollutants to freshen the air.

Moisture Control

• Use dehumidifiers in humid or damp areas to keep indoor humidity levels in check and prevent mold.
• Repair leaks, make sure water drains properly, and keep your foundation ventilated to prevent moisture from seeping into your home.
• Vent bathrooms, kitchens, and laundry areas with exhaust fans to remove humidity.
• Monitor indoor humidity with a hygrometer and aim to keep levels between 30-50% for optimal comfort and air quality.

Advanced Air Purification

Most air purification systems use outdated technology, leaving homes and commercial spaces only partially protected. Maple Air’s Pür Plasma technology is the gold standard for indoor air quality, offering up to 15 times the performance of conventional systems. It neutralizes viruses, mold, fungi, and odors, while breaking down harmful gases and VOCs – unlike standard filters that only capture what passes through them.

100% organic, ozone-free, and built to last longer than typical HVAC systems, Pür Plasma provides reliable, low-maintenance air purification 24/7. Trusted by Hilton Hotels, Penn State University, and major gyms, it delivers safer, fresher, and healthier environments in real-world settings. Testing has shown more than a 90% decrease in airborne pollutants.

Homeowners often feel the difference right away. Their house smells cleaner, stubborn odors from cooking or pets fade, and the whole house feels healthier and more comfortable. Contact us today to order your new system.

Protect Your Home – and Your Health

Indoor air contaminants – from radon and mold to chemical pollutants – are a real concern in many North Carolina homes. Taking proactive steps like testing, mitigation, and air quality management can make a big difference, and solutions like Maple Air’s Pür Plasma system help keep your indoor environment cleaner, safer, and healthier.