Indoor Air Quality in Your Home: How to Test and Improve Indoor Air Quality

Why Indoor Air Quality is ImportantPeople often look at outdoor pollution as a sign they need to take better care of their local air. However, the quality of indoor air is often much worse than it is outside. As such, homeowners may find their indoor air quality causes them various health problems, from throat or skin irritation to asthma, migraines, or even cancer. The problem is that people may not be aware of the severity of the problem until they are already facing health conditions. With the following information, homeowners will know the common causes of poor indoor air quality and things they can do to improve it.

Potential Indoor Air Pollutants

There are numerous indoor air pollutants, and many of them relate to material components of the structure or the function of the home's systems. By researching the most common contaminants, people may be able to minimize or prevent them.


Asbestos is a natural mineral that was a common component in many building materials until the 1970s and 1980s. It was popular due to its ability to minimize the spread of fires. At that time, health experts realized asbestos could release tiny fibers into the air when disturbed. If people breathe in those fibers, they may be at risk for various possible health problems. Homeowners can assume if their homes were built in the 1970s or earlier, the structure might contain asbestos in the following areas:

  • Insulation
  • Ceiling texture
  • Paint
  • Drywall

People unsure of the material makeup of these aspects of their homes may want to schedule a consultation with an asbestos remediation expert. These professionals can help identify existing sources of asbestos and determine the best course of action.

Biological Pollutants

Homeowners likely have to deal with several types of biological pollutants. Some of them may come from outside, tracked or blown in while doors and windows are open. Others may accumulate in the home due to environmental conditions or the presence of pets. Common pollutants include:

  • Pollen
  • Mold
  • Pet dander
  • Dust
  • Insects or mites

Most of these are particles, although some such as pet saliva, can be liquid. In most cases, these contaminants will accumulate in soft materials throughout the home, such as carpets, drapes, or bedding. Test kits may be available for certain types of pollutants like mold or pollen. People should consider hiring an expert to inspect for insects or pests. Sometimes, people can only determine a contaminant's presence by testing themselves for an allergic reaction and identifying the most likely sources of the exposure.

Carbon Monoxide

Carbon Monoxide Pollution in AirUnlike many other types of pollutants, carbon monoxide can be deadly without a long accumulation of exposure. This byproduct of combustion usually arises as a result of heat-producing equipment or appliances in the home like:

  • Gas furnace
  • Gas oven or range
  • Wood or gas-burning fireplace

Carbon monoxide can be tricky to identify in the home because it is colorless and odorless. Unlike natural gas, which has a distinct odor, people may have no warning that carbon monoxide is spreading in the home. It may not take long, only hours in some cases, for carbon monoxide to cause confusion, severe headaches, and even death. The best way to test for carbon monoxide is to purchase and use a carbon monoxide detector in the house. Experts suggest installing the detector several feet away from the fuel-burning appliance and consider installing more than one throughout the home.


Formaldehyde is a preservative commonly found in certain building materials like wood flooring. It is also a byproduct of certain types of combustion, such as cigarette smoke. Over time, formaldehyde trapped in building materials may eventually release into the air. This gas has an overwhelming odor that homeowners may notice at first, although it will dissipate over time.

Significant exposure to formaldehyde can cause skin or throat irritation and even increase the risk for certain types of cancer with heavy exposure. Homeowners may not know they have a high formaldehyde level in their homes unless they purchase a test kit. The kit involves placing a unit in the room for 24 hours, sealing it, and mailing it to a lab for testing. People can minimize their exposure by researching products that reduce formaldehyde usage and look for safe heat production methods with good ventilation in their homes.


Although lead is a heavier element, tiny particles of it can become airborne. The most common sources of lead exposure in the home relate to lead paint stirred up during renovation or cleaning and lead dust tracked inside from contaminated soil. In most cases, people will not realize that they have a lead problem unless they know how to look for it.

Typically, homes built in the 1970s or earlier may have layers of lead paint on:

  • Walls
  • Windowsills
  • Natural wood siding
  • Wood staircases

People with homes built in the 1940s or earlier may also have lead plumbing pipes or copper plumbing pipes soldered using lead. Lead exposure causes developmental problems in infants and children and cancers or other health problems in adults. Testing for lead usually involves obtaining a sample of paint for lab testing, which is a practical choice for homeowners looking to renovate older homes.

Nitrogen Dioxide

Much like carbon monoxide, nitrogen dioxide is a common byproduct of combustion. For example, people may be exposed to nitrogen dioxide outside when they stand around vehicles that are actively burning gasoline. Inside the home, nitrogen dioxide can accumulate when a fuel-burning appliance does not ventilate properly. If a homeowner runs a wood-burning stove with a chimney filled with salt and creosote, it may not vent to the outdoors correctly. Similarly, a furnace or stove with insufficient ventilation may force nitrogen dioxide back into the house instead of releasing it outside. Exposure to nitrogen dioxide can cause throat irritation, leading to chronic bronchitis or certain types of lung disease. The ideal method to minimize exposure to nitrogen dioxide indoors is to purchase and use ventilation equipment correctly.


Radon is a natural element that may be present in higher quantities in certain parts of the country. In homes with insufficient ventilation, radon outside may translate into higher exposure to radon inside. People may not know they have a problem with radon exposure until they are diagnosed with a serious condition. People who have a history of smoking are more likely to be at risk for lung cancer due to radon exposure.

When people buy a home, they may have the opportunity to test for the presence of radon. In areas where radon exposure is higher on average, people may want to request testing from a qualified professional. In many cases, reducing radon accumulation in the home is as simple as purchasing and using a specific ventilation device.

Indoor Particulate Matter

Indoor Particulate Matter in Your HomeThe presence of contaminants affecting indoor air quality is not necessarily visible. In some cases, they are so small that humans cannot detect them. These pollutants, commonly referred to as particulate matter, vary in type, source, and long-term effects. The smallest particulate matter is sufficiently tiny and can be easily inhaled or enter the bloodstream. Sources include:

  • Incense
  • Smoke
  • Pet dander or saliva
  • Cockroach debris
  • Pollen or other common allergens

The problem with determining particulate matter is there are most likely many types in the home at any given point in time. The chief issue is the quantity and the mobility of these particles. In essence, the more particular matter releases into the air, the easier it is to consume. Homeowners can purchase test kits or hire professionals to test for many of these contaminants. Otherwise, they may prefer to move straight to mitigation of the problem.


The presence of smoke in the home can be a significant indoor air pollutant. Smoke comes from a variety of possible sources, such as:

  • Cigarette smoking
  • Wood-burning fireplaces or stoves
  • Smoke that arises from cooking

In any of these cases, smoke inhalation can quickly become a problem. People will usually notice that smoke exposure immediately does not feel good, as smoke can irritate the eyes, nose, throat, and lungs. With long-term exposure to smoke from the sources, people may be at risk for developing long-term health conditions like bronchitis or lung cancer.

Although smoke in the home may be evident at the time of combustion, its presence lingers over time. For example, someone who regularly smokes inside the house or a buyer who purchases a home from a seller who smoked may have lower air quality — even if they are not actively smoking at the time. Minimizing the sources of smoke and increasing ventilation are the best ways to prevent these problems.

Volatile Organic Compounds (VOCs)

Volatile organic compounds are also present in things throughout the home. Homeowners may be aware they exist because many have a strong odor and may cause reactions very quickly. Others may take years to release these gases and will be less noticeable. People can look for VOCs in a variety of places, such as:

  • Building materials
  • Leather furniture
  • Cleaning products and solvents
  • Paint
  • Materials for hobbies, such as resin casting
  • Fuel, like stored gasoline or propane

The effect of VOCs depends on the type and amount. For example, someone who opens a bottle of paint thinner will immediately notice the noxious odor. On the other hand, someone who buys a home with freshly laid wood flooring may not notice the smell of wood preservatives. The best time to test for VOCs in the home is right after a remodeling project. Professionals can use tools to identify the presence of thousands of possible compounds, as well as their severity.

How to Improve Indoor Air Quality

While controlling the sources of indoor pollutants is an important part of maintaining a healthy home, other steps may be necessary. Homeowners who pay attention to their home's filtration and ventilation systems may have a better chance of removing harmful contaminants and keeping them out.

Use Air Filters

Most heating and cooling methods in the home on a system-wide scale offer filtration to remove certain types of contaminants. Homeowners who have central air conditioning or use a furnace or heat pump will have air filters that come with the system. The right kind of filter is essential, and people must plan to change their filters regularly. Air filters are rated using a minimum efficiency reporting value, which ranges from 1 to 16.

Most homeowners probably have a filter with a rating between 5 and 8, although some may have filters that do less. Homes with residents who have allergies or asthma may prefer to buy a filter with a MERV rating of 9 to 12 or higher. These filters can collect dust and debris, so they should be changed at least once every three months. Clogged filters can pass on allergens or cause the HVAC system to become dirty and malfunction. Higher filtration options may need to be changed as frequently as once a month for best use.

Ventilate Your Home

Ventilate Your Home's Air to Improve QualityBesides controlling what comes into the home, homeowners may want to take additional steps to ensure the home's ventilation can remove harmful pollutants. There are a few different types of ventilation the people can use, and the right one for the task depends on the need. For example, someone trying to get the noxious odor of cooked fish out of the kitchen may want to turn on the fan to circulate the air or open a window. By comparison, ventilation above the range is necessary to remove heat, moisture, and fuel byproducts. A bathroom fan works similarly by drawing air upward so it can be safely vented outside. Otherwise, homeowners should use the ventilation built into their home's HVAC system. This type of ventilation circulates air throughout the house and provides a fresh air supply from the outside, filtered before it is conditioned.

Add House Plants

Homeowners may want to add certain house plants to the home because they function to neutralize common contaminants. Most people are probably aware of photosynthesis, wherein a plant takes carbon dioxide from the air and converts it into oxygen. However, many plants can also absorb pollutants like carbon monoxide or VOCs and still return only oxygen. These plants include:

  • Golden Pothos
  • Peace Lily
  • English Ivy
  • Aloe Vera
  • Spider plant
  • Snake plant
  • Bamboo palm

Although people may think house plants are uniformly good for the home, they may want to take precautions. Many of these plants need a certain level of bright but indirect sunlight to thrive. Additionally, house plants may not necessarily be safe for pets or small children, especially those who may try to chew on leaves or flowers.

Keep Your Home Clean

In most cases, indoor air quality is a factor of accumulation in the home. As such, the best way for homeowners to minimize the accumulation of contaminants inside is to clean their houses regularly. Certain types of pollutants will be challenging to manage if they are regularly introduced into the home. However, homeowners may be able to manage them by:

  • Washing bedding at least once a week, especially pet bedding
  • Sweeping hard floors daily
  • Vacuuming carpets and scheduling water-based carpet cleaning twice a year
  • Minimizing clutter on surfaces
  • Dusting once a week and sweeping or vacuuming afterward
  • Keeping ceiling fans, windows, and doors free of dust and debris
  • Cleaning surfaces with low-VOC cleaning products
  • Storing harsh chemicals outside of the home in a well-ventilated space
  • Eliminating excess pollutants in the home that are not needed, like old paint

People may need to engage in a periodic, deep cleaning once or twice a year. This is more likely to be necessary for homes with an extensive accumulation of smoke or water damage.

Invest in Air Purifiers

Use Air Purifiers to Improve Air QualityIf homeowners find the ventilation available is insufficient to filter out pollutants, they may want to consider investing in air purifiers. Air purifiers may come in a variety of forms. Most of the time, they contain a filter that can prevent particles from passing through. As the air purifier cycles air, it continues to draw the particles into the filter until it is full. For this type of air purifier, homeowners can expect to replace the air filter at least once every three months. Additionally, air purifiers only work while they are running, so people should plan for regular operation.

Other types of air purifiers may use activated carbon to filter out gases like VOCs from the air. Like air filters, activated carbon must be replaced regularly. It is worth keeping in mind that air purifiers at home often cannot meet the filtration levels obtained in the lab. Homeowners should plan to use air purifiers in addition to other methods of air quality management.

Try a Dehumidifier

The humidity of the home can create an environment in which certain pollutants can grow or become more difficult to remove. Using a dehumidifier may help prevent this. An HVAC system can maintain an ideal humidity for the home, despite the humidity outside. However, the system's ability to control humidity depends on its sizing and the frequency of use. Homeowners who buy an air conditioner that is too large may cool the home quickly but fail to remove humidity.

Even with a sufficient level of conditioning, certain homes might require extra moisture control. Using a dehumidifier in the kitchen or bathroom can control humidity and minimize mildew and mold growth. People may want to choose the one with the highest capacity. In most cases, homeowners only need to empty a drip pan as it accumulates water.

Buy the Right Cleaning Products

Proper use of cleaning products and air fresheners is key to reducing the likelihood that pollutants will continue to accumulate, even in a clean home. Many homeowners may purchase and use products designed to add a fresh scent to the air rather than remove bad odors or pollutants. Specifically, products containing pine or citrus oils react with ozone, causing it to increase. Similarly, homeowners may want to avoid using air purifiers that use ionizers to draw particles and gases from the air, which can also produce ozone.

How to Improve Air Quality in Your HomeThe safest route for cleaning is to minimize the amount of product used, rinse well, and select options with low VOCs. For example, homeowners may get an excellent result from using lemon juice or vinegar and baking soda instead of ammonia or bleach. People who must use harsh solvents or cleansers should ensure the area is well-ventilated for several hours afterward.

As bad as the air could be outside, it is often much worse in the home. Fortunately, it does not have to be this way. With improvements to ventilation and choices for products homeowners can buy, it is easier to avoid bringing in pollutants that harm air quality. Understanding the extent of the problem through testing allows people to determine how best to remove existing contaminants and prevent them from coming back. With this minor investment of time and money, homeowners may feel better and avoid some of the most common health conditions associated with low indoor air quality.

Further Reading


Post a Comment