This article discusses the most common contaminants in our homes, their sources, ways to identify them, their effects on our health, and how we can reduce their risks.
Over the last few decades, outdoor air quality has improved throughout North America. Still, the air quality inside our buildings has stayed the same or worsened during the same time frame. Outdoor CO2 Emissions and Aggregate Emissions (of 6 common pollutants) are down (view EPA air quality trends here). On the other hand, indoor pollutant levels are, on average, 2 to 5 times higher than the outside, according to the EPA. This trend is especially concerning because most Americans spend around 90 percent of their time indoors.
These trends indicate that anyone concerned about air quality and health should focus on their homes. Knowledge is power, and luckily there are steps we can take to reduce the risk to ourselves and our families.
What can cause health issues in our homes?
Mold or fungi are living organisms that reproduce by sending spores into the air. Molds can deteriorate bio-degradable materials (financial damage), and some molds can potentially cause health problems.
Common sources of Mold in our homes and buildings:
Mold thrives on persistently wet surfaces inside the home. Mold grows at roof/plumbing leaks, condensation issues from ventilation/insulation and heating/cooling issues, and water penetration from the outside. The number one cause of mold or air quality issues in our area is wet crawlspaces and basements caused by water penetration from the outside- air quality issues develop when the moisture and fungus penetrate through finishes and into our living areas.
The EPA on Mold:
Regulations and Standards:
Currently, there are no EPA regulations or standards for airborne mold contaminants.
EPA on Mold and Health:
Molds have the potential to cause health problems. Molds produce allergens (substances that can cause allergic reactions), irritants, and in some cases, potentially toxic substances (mycotoxins). Inhaling or touching mold or mold spores may cause allergic reactions in sensitive individuals. Allergic responses include hay fever-type symptoms, such as sneezing, runny nose, red eyes, and skin rash (dermatitis). Allergic reactions to mold are common. They can be immediate or delayed. Molds can also cause asthma attacks in people with asthma who are allergic to mold. In addition, mold exposure can irritate the eyes, skin, nose, throat, and lungs of mold-allergic and non-allergic people. Symptoms other than the allergic and irritant types are not commonly reported as a result of inhaling mold.
How can Mold be identified in our homes?
Mold issues are moisture issues. Non-professionals can also recognize potential mold or moisture issues in the home.
Any smell that you would describe as musty, moldy, damp, or stale could indicate high humidity and mold.
White or green mold growing on furniture and cabinets is likely Aspergillus/Penicillium or Cladosporium – these have allergenic potential. Black mold, or Stachybotrys, grows on more saturated surfaces.
Known sources of water
- Active roof leaks
- Plumbing leaks (especially under cabinets)
- Water penetration from outside (especially baseboard trim at finished basements)
- Wet Basement or Crawl Space
- wet walls
- standing water
- moisture damaged insulation
- mold on the framing
- High moisture readings at the baseboard trim at finished basements
- High moisture readings at the finished floor over wet/humid crawl spaces
- Cupped floors
- High moisture in the air or a relative humidity of 60% or more
- A hygrometer can be purchased for less than $20 and are an essential tool for every homeowner. Hygrometers monitor humidity in the air.
- When the relative humidity of the indoor air is consistently over 60% (especially in rainy or hot months) this indicates humid conditions that are conducive to mold
Professional Mold Testing and Evaluations
Identifying mold or moisture issues can be more challenging during real estate transactions when access to the home is limited. The buyer relies on seller disclosure regarding the history of leaks and water penetration. It can also be difficult to determine conditions at finished basements when there is little access or access to the foundation walls. In these cases, professional Mold Testing or a Mold Evaluation may be recommended to gather more information.
Our company (Builder Buddy) performs Mold Tests and Mold Evaluations, and we also look for potential air quality issues during our regular Home Inspections. For more information, check out our popular article on Interpreting Mold Test Results or Should I Order a Mold Test? The advantage of hiring a Home Inspector or an independent professional (who does not offer repairs) is that their analyses will be unbiased.
How can we reduce the risk of Mold in our homes?
Mold issues are moisture issues which are why our Home Inspections are very similar to our Mold Evaluations- we are always looking for sources of unwanted moisture. The first step in mitigating a mold problem is to identify the source of water correctly. If the source of moisture is removed, the area will dry out, and the fungi/mold will become inactive. Mold is mitigated by keeping areas clean and dry. In some cases, selective demolition will be needed behind ceilings and walls to expose areas to dehumidification and sterilization and to remove contaminated materials. In many cases, repairs will be needed to prevent water penetration from the outside (grading, drainage, roofing, etc.)
Mold in Asheville and WNC
Much of Western North Carolina is densely wooded temperate rainforests. Our region has high annual rainfall and a high annual dew point (a better indicator of mold than humidity). These conditions contribute to more than typical wet/moldy crawl spaces and basements, which can cause Indoor Air Quality issues in our region. Builder Buddy inspects for wet/moldy conditions as part of our Home Inspections, Commercial Inspections, Annual Maintenance Inspections, and Home Health Check-ups.
About Biological Pollutants:
Biological contaminants are created by living things in our homes and have allergenic potential or could spread disease. According to the EPA, some biological contaminants trigger allergic reactions in some people.
Common sources of Biological Pollutants:
According to the EPA, biological pollutants include:
- Animal dander
- Mold (See above)
- Mites and Bed bugs
- Droppings and urine from rodents and other pests
- Droppings and body parts from cockroaches and other insects
According to the EPA, biological contaminants are often found in damp/wet areas and draperies, bedding, carpet, and other areas where dust collects.
The EPA on Biological Pollutants:
Regulations and Standards:
Currently, there are no EPA regulations or standards for Biological Pollutants.
EPA on Biological Pollutants and Health:
Allergic reactions include hypersensitivity pneumonitis, allergic rhinitis, and some types of asthma. Children, elderly people, and people with breathing problems, allergies, and lung diseases are particularly susceptible to disease-causing biological agents in the indoor air. Mold, dust mites, pet dander, pest droppings or body parts can trigger asthma. Tuberculosis, measles, staphylococcus infections, chicken pox, Legionella, and influenza are known to be transmitted by air.
How can Biological Pollutants be identified in our homes?
Environmental Testing companies in your area may offer to screen for Biological Pollutants. Some labs offer Allergen test kits – the tests analyze dust samples taken from bedding, furniture, and floors. Some, but not all, Pest Control Companies can help identify and treat some potential biological contaminant pests and insects like rodents, cockroaches, etc.
How can we reduce the risk of Biological Pollutants in our homes?
The following steps can help prevent Biological Pollutants:
Keep the home dry.
- Maintain consistent temperatures year-round with central heating and cooling
- Central heating and cooling are designed to maintain dry conditions in the home (60%RH or drier)
The use of humidifiers should be limited, or they should be maintained and serviced regularly
Basements and crawl spaces may need additional dehumidification
Grading and drainage improvements may be needed to prevent water penetration from the outside
Keep the home clean.
- Bedding, draperies, carpets, furniture, and other fabrics should be cleaned regularly
- Fabrics should be washed with the hottest washer setting
- Allergen-proof mattress encasements can be used
- Use central vacuums that exit to the outside or vacuums with HEPA filters
Keep the home well-ventilated.
- Ideally, bathroom and range vents should exit to the outside
- Dryers vents must exit to the outside
- Attics and crawl spaces should be adequately ventilated
Order Regular Inspections and Servicing by Qualified professionals.
- Industrial Hygienists
- Home Inspectors
- Pest Companies
- HVAC Companies
Biological Pollutants in Asheville and WNC
In 2022 AccuWeather predicted our region would be one of the worst for Grass, Tree, and Weed pollen- see that article here. Aside from pollen, our average annual dew point and humidity are conducive to many Biological Pollutants in our homes. Builder Buddy inspects for rodent activity as part of our Home Inspections, Commercial Inspections, Annual Maintenance Inspections, and Home Health Check-Ups.
About Radon Gas:
Radon is a byproduct of decaying radioactive elements (such as Uranium). When Radon Gas decays, it emits dangerous alpha particles.
Source of Radon Gas:
We have naturally occurring radioactive elements (such as Uranium) in the mountains of Western North Carolina, which can cause high levels of radioactive Radon Gas in our home. Radon gas seeps upward from the ground into our living areas.
The EPA on Radon Gas:
Regulations and Standards
The EPA recommends homes be fixed if the radon level is 4pCi/L (picocuries per liter) or more. Because there is no known safe level of radon exposure, EPA recommends that Americans consider fixing their home for radon levels between 2 pCi/L and 4 pCi/L.
The EPA on Radon and Health
According to the EPA, Radon is the second leading cause of lung cancer after smoking. (Check to see if high levels of radon are in your area)
How can high levels of Radon be identified in our homes?
The EPA has a resource about testing here. Homeowners can use test kits; however, they should follow instructions carefully because an accurate test will require that all testing protocols are followed– especially regarding test placement, closed conditions, and test handling. Testing professionals, like Home Inspectors and Radon Mitigation Installers, can perform a test for you (usually under $200). Another thing to remember is that Radon Testing for real estate transactions has more stringent regulatory requirements (per the EPA) and is best left to a professional.
How can we reduce the risk of Radon gas in our homes?
Radon Mitigation is fairly affordable and is usually very effective at reducing Radon to safe levels in the home. Radon mitigation in our area usually costs less than $2000 and includes retesting. Radon Mitigation strategies typically involve capturing radon gas in the crawl space or slab and venting it out above the roofline before it has a chance to enter our living areas.
Radon Gas in Asheville and WNC
Asheville and Buncombe County are located in the EPA red zone for radon (Zone 1) which has the most significant potential for indoor radon levels of all the zones. See the EPA NC Radon map here. See the US EPA radon map here. Builder Buddy provides radon testing throughout Asheville and WNC.
About Toxic Emissions:
Carbon Monoxide, Nitrogen Dioxide, and other potentially toxic exhaust gases can be emitted into the living areas of our homes by faulty fuel-burning appliances.
Common sources of Toxic Emissions in our homes and buildings:
Wood/pellet stoves and fireplaces
Vented and Unvented gas heaters and fireplaces
Oil/gas boilers, furnaces, and generators
Oil/gas appliances such as dryers, range/ovens, etc.
Gas-powered vehicles (garages) such as cars, golf carts, ATVs, motorcycles, etc.
The EPA on Toxic Emissions:
Regulations and Standards
EPA Regulations and Standards on Toxic Emissions:
No standards have been agreed upon for carbon monoxide or nitrogen oxides in indoor air.
State Regulations and Standards on Toxic Emissions:
Requirements and laws for carbon monoxide detectors differ from state to state- most states have enacted statutes regarding carbon monoxide detectors.
OSHA Regulations and Standards on Toxic Emissions:
OSHA standards prohibit worker exposure to more than 50 parts of CO gas per million parts of air averaged during 8 hours.
The EPA on Nitrogen Dioxide or NO2 and Health:
Breathing air with a high concentration of NO2 can irritate airways in the human respiratory system. Such exposures over short periods can aggravate respiratory diseases, particularly asthma, leading to respiratory symptoms (such as coughing, wheezing, or difficulty breathing), hospital admissions, and visits to emergency rooms.
The EPA on Carbon Monoxide or CO and Health:
At low concentrations, CO can cause fatigue in healthy people and chest pain in people with heart disease. At higher concentrations, CO can cause impaired vision and coordination; headaches; dizziness; confusion; nausea. CO can cause flu-like symptoms that clear up after leaving home. CO is fatal at very high concentrations.
How can Toxic Emissions be identified in our homes?
Gas/oil furnaces, wall heaters, boilers, and water heaters should be inspected and maintained annually.
Chimneys of all types should be inspected and serviced annually
Carbon monoxide detectors should be tested regularly and replaced every ten years. See our article Where Should Smoke/CO Detectors Be Placed? Homes with fuel-burning appliances can also be made safer with Air Quality Monitoring devices/monitors that sense other gases such as Nitrogen Dioxide.
Maintenance Home Inspections should be performed annually by a state-licensed Home Inspector
Some companies, like ours, offer Home Maintenance Checks (see below) that focus on Indoor Air Quality (IAQ)
How can we reduce the risk of Toxic Emissions in our homes?
Reducing or eliminating fuel-burning appliances in and around the home
Upgrade and maintain the Smoke/CO detection system
Inspect and service all fuel-burning appliances annually
Toxic Emissions in Asheville and WNC:
Our cold climate means that fireplaces, furnaces, and backup gas generators are very common. Most homes outside the city areas have some on-site fuel storage (oil/kerosene/propane)- many of them are rural, historical, or vacation homes. Houses within city limits have access to natural gas, which is why fuel-burning appliances are common throughout our region. These fireplaces and fuel-burning appliances must be properly installed and maintained annually to prevent unhealthy emissions and indoor air quality issues. Our experience as a local inspection company is that most households in our area do not inspect or service their fuel-burning fireplaces and appliances annually. Many of these appliances were installed by homeowners or other unlicensed people. Older fireplaces, furnaces, unvented gas stoves, and unvented fireplaces are also prevalent in our region- these appliances can continue to heat the home while emitting hazardous Carbon Monoxide and other exhausts into our homes (without the occupants knowing it). It is also our experience that most households in our region do not have Carbon Monoxide Detectors, do not have them properly installed, or they are expired or missing batteries. Builder Buddy inspects fuel-burning appliances as part of our Home Inspections, Commercial Inspections, Annual Maintenance Inspections, and Home Health Check-Ups.
Lead is a naturally occurring toxic metal. Because of its malleability and corrosion resistance Lead was commonly used in residential plumbing materials and paints.
Common sources of Lead in our homes and buildings:
Homes built before 1978 are presumed to have lead-containing paints. Flaking paint is a concern with older homes, primarily when it is found inside.
Lead-containing Plumbing Materials:
Lead was commonly used in plumbing materials in cities and homes built before 1986. Some common lead-containing materials in our area include:
- Lead particles can attach to the surface of Galvanized pipes
- Older Brass or Chrome-Plated faucets
- Lead solder in copper pipes
The risk of leaching metals is more of a concern with acidic water.
The EPA on Lead
EPA Regulations and Standards
Lead is a pollutant regulated by many laws administered by EPA (paint, dust, and soil). (EPA information on Lead Regulations can be found here)
EPA on Lead and Health
Lead is known to cause a range of health effects, from behavioral problems and learning disabilities to seizures and death. Children six years old and under are most at risk from exposure to lead-based paint because they crawl on the floor and they put their hands and other items which can have lead-based paint dust on them into their mouths.
How can Lead Paint be identified in our homes?
If the house was built before 1978, it is generally assumed that the paint has lead. The EPA maintains a list of Certified Risk Assessors and Inspectors that can help families with small children inspect for lead or assess the risks. Environmental Testing companies near you may offer lead testing. Many General Contractors and Home Inspectors can help identify familiar sources of lead in the home.
Regarding Lead plumbing: Here is the EPA resource for your annual drinking water report (or Consumer Confidence Report or CCR) from your local supplier. A licensed plumber or home inspector can help identify lead pipes in your home.
How can we reduce the risk of Lead Paint in our homes?
The paint should be well maintained inside and out by a Certified Lead Professional. Lead plumbing should be identified and removed if possible.
For more information: EPA Strategies for Protecting your Family from Sources of Lead
Lead in Asheville and WNC
Asheville and WNC include many historic towns and buildings (Buncombe county was established in 1792). All homes built before 1978 are assumed to have some lead-containing paints. Many homes built before 1986 have lead-containing plumbing materials known to leach into the water. Our company, Builder Buddy, helps recognize familiar sources of presumed lead-containing materials during our Home Inspections, Commercial Inspections, and Home Check-Ups.
About Asbestos Materials:
Asbestos is a naturally occurring mineral fiber that occurs in rock and soil. Because of its natural heat, corrosion, and chemical resistance, asbestos was commonly found in many residential construction materials until the late 1970s.
Common sources of Asbestos Materials in our homes and buildings:
In 1977 and 1978, the EPA limited the use of asbestos in many household products. Asbestos materials were commonly installed in homes between the 1930s and 1970s, so asbestos concerns are primarily limited to older homes. Some stock-piled asbestos materials were installed well into the 1980s and even into the 1990s.
Some sources of Asbestos in the home, according to the EPA:
Older Attic and wall insulation containing vermiculite
Older Vinyl floor tiles and the backing on vinyl sheet flooring and adhesives (9×9” tiles often found in basements and the ‘black mastic’ adhesive)
Older roofing and siding shingles
Older textured paint and patching compounds used on walls and ceilings
Older walls and floors around wood-burning stoves are protected with asbestos paper, millboard, or cement sheets
Older Hot water and steam (boiler) pipes insulation
Older Oil and coal furnaces and door gaskets
The EPA on Asbestos Materials:
EPA Regulations and Standards
The EPA has many Laws and Regulations about asbestos- more information can be found here.
EPA on Asbestos and Health
Exposure to asbestos increases your risk of developing lung disease. That risk is made worse by smoking. In general, the greater the exposure to asbestos, the greater the chance of developing harmful health effects.
Three of the major health effects associated with asbestos exposure are:
mesothelioma, a rare form of cancer that is found in the thin lining of the lung, chest, abdomen, and heart
asbestosis, a serious progressive, long-term, non-cancer disease of the lungs
How can Asbestos Materials be identified in our homes?
Environmental Testing Companies in your area may offer Asbestos testing– many states also maintain a list of Asbestos Inspectors and Contractors. There are well-known PACMs or Presumed Asbestos Containing Materials that Home Inspection professionals and General Contractors can recognize.
How can we reduce the risk of Asbestos Materials in our homes?
Well-maintained and un-disturbed asbestos-containing materials are not likely to pose a health risk, according to the EPA. In some cases, the materials can be removed by a trained and accredited asbestos professional.
Asbestos Materials in Asheville and WNC
Asheville area has many older homes built between the 1930s through the 1970s, which is why asbestos products in the home are a concern in our area. Builder Buddy identifies common asbestos materials during our Home Inspections, Commercial Inspections, and Home Health Check-ups.
Electromagnetic fields and radiation are waves of electric and magnetic energy moving together through space. EMFs are categorized into two different types- ionizing and non-ionizing.
Ionizing or Higher Frequency EMFs:
Ionizing radiation is a mid to high-frequency radiation which can, under certain circumstances, lead to cellular and or DNA damage with prolonged exposure. Examples of Ionizing EMFs are alpha particles, beta particles, positrons, gamma rays, and x-rays.
Non-Ionizing or Low to Mid Frequency EMFs:
Non-Ionizing EMFs can heat substances (like microwaves) but do not have enough energy to remove electrons from atoms and molecules or directly damage DNA or cells. Examples of Non-ionizing EMFs are Ultraviolet, Infrared, Microwave, Radio Frequency, and Extremely Low Frequency.
Common Sources of EMFs in our Homes and Buildings:
Ionizing sources of radiation in the home that can cause harm:
According to the EPA, Ionizing radiation sources that might be found in a typical home are:
Americium in Ionization Smoke Detectors
Natural Radionuclides in Private Wells (See Drinking Water Contamination)
Natural Radionuclides in Public Drinking Water (See Drinking Water Contamination)
Radon Gas (See Radon)
Non-ionizing sources of radiation in the home that can cause harm:
- Microwave Ovens
The FDA advises against standing directly in front of or up against a microwave open while operating to avoid harm from any possible leaks. The FDA recommends replacing the oven if the door doesn’t close firmly or is bent, warped, or otherwise damaged.
Other Non-ionizing sources of radiation in the home that is still being studied:
Electrical Appliances and Lights
Wireless devices, Cell phones, Bluetooth, and WiFi
Government Agencies on EMFs:
The EPA on EMFs:
There are no US Federal standards limiting residential or occupational exposure to electric and magnetic fields (EMF) from power lines. However, some states have set standards for transmission line fields.
A few studies have connected EMF and health effects, but they have not been able to be repeated. This means that they are inconclusive. Scientists continue to research the issue.
The CDC on Ultraviolet, Radiofrequency, and Microwave radiation exposure:
Too much UV radiation can cause skin burns, premature aging of the skin, eye damage, and skin cancer. The majority of skin cancers are caused by exposure to UV radiation. Intense, direct exposure to radiofrequency or microwave radiation may result in damage to tissue due to heat.
The FDA on Microwave radiation:
Two areas of the body, the eyes, and the testes are particularly vulnerable to RF heating because there is relatively little blood flow to carry away excess heat. Exposure to high levels of microwaves can cause skin burns or cataracts.
The NIEHS on EMFs:
NIEHS acknowledges additional research is needed and recommends continued education on practical ways to reduce exposure to EMFs.
How can EMFs be identified in our homes?
No federal or state regulations exist for EMF licensing, testing, or protocols. Independent EMF testing/inspecting Certification programs do exist, however, and a Certified EMF Testing Specialist can be consulted for more information. See Sources of EMFs (above) for a list of popular home devices well-known to emit EMFs. EMFs can also be tested with meters that measure AC magnetic, AC electric, and RF/microwave non-ionizing radiation.
How can we reduce the risk of EMFs in our homes?
According to the EPA, if you are concerned about possible health risks from EMF,s you can:
Increase the distance between yourself and the source
Limit the time spent around the source
Volatile Organic Compounds (VOCs) are chemicals that readily vaporize into the air or dissolve in water, even at ambient temperatures. Thousands of products and building materials containing VOCs are commonly found in a typical household.
Common Sources of VOCs in our Homes and Buildings:
Composite wood products (plywood, OSB, fiberboard, cabinets, etc.)
Vinyl and adhesives (vinyl flooring, vinyl siding, countertops, etc.)
Flame retardant Home Insulation, Foams, and Fabrics
Home Furnishings (polyester/vinyl/plastic fabrics and poly fiber fill/padding, etc.)
Synthetic Rugs, Carpeting, and Padding
Chlorine in tap water (or chlorinated well water)
EPA regulations and standards on VOCs:
EPA does regulate VOCs in some household products under the Clean Air Act (CAA); however, the regulations that we have promulgated for VOCs in architectural coatings and consumer products are in place only because many VOCs photochemical react in the atmosphere to produce ozone, a component of smog. Some products that are labeled as “no VOC” or “low VOC” under the CAA can actually contain volatile organic chemicals that are toxic, sometimes at high levels. The reason is that some chemicals that are toxic are exempt from the VOC regulations because they are not considered to be photochemically reactive.
While we do regulate VOCs in outdoor air, from an indoor air perspective, EPA has no authority to regulate household products (or any other aspect of indoor air quality). Even if we had the authority to regulate indoor air quality, it would be difficult to regulate household (or other) products because we have no authority to collect information on the chemical content of products in the marketplace (nor does any Federal Agency)
EPA on VOCs and Health Effects
VOCs include a variety of chemicals, some of which may have short and long-term adverse health effects. Concentrations of many VOCs are consistently higher indoors (up to ten times higher) than outdoors. No federally enforceable standards have been set for VOCs in non-industrial settings.
Health effects may include:
- Eye, nose, and throat irritation
- Headaches, loss of coordination, and nausea
- Damage to the liver, kidney, and central nervous system
- Some organics can cause cancer in animals, some are suspected or known to cause cancer in humans.
How can VOCs be identified in our homes?
Most sources of VOCs are well known– see Sources of VOCs above. According to the EPA, Formaldehyde is one of the best-known VOCs and is one of the few indoor air pollutants that can be readily measured. Formaldehyde testing equipment can be purchased online. An Environmental Testing Company can also test VOCs in one of two ways:
PID meters (photo-ionizing detectors)
Collecting air samples for lab analysis
How can we reduce the risk of VOCs in our homes?
Steps can be taken to reduce exposure to VOCs by
- Improving ventilation when using products that contain VOCs
- Reducing or limiting the amount of VOC-containing products in the home
- Storing VOC products outside the home
- Meeting or exceeding label precautions on products that contain VOCs
- Keep VOC-containing products away from children and pets
The EPA provides more guidance on reducing exposure to VOCs here.