Your home should be your safe place. But, how can it be if you’re not sure whether the air you breathe inside it is healthy?

Poor indoor air quality (IAQ) can worsen allergies and asthma and cause persistent headaches, nausea, and irritation of the eyes and throat. In more severe cases, exposure to harmful substances like carbon monoxide can pose life-threatening risks.

Testing your home’s air quality is the first crucial step toward creating a healthier living environment. This guide will walk you through how to test your IAQ effectively and identify key pollutants to watch out for.

There’s no strict rule about how often you should test your home’s air quality, but there are several scenarios when testing becomes particularly important:

• After moving or renovating: Bringing in new furniture, or using different building materials and paints can release many pollutants into the air. That’s why it’s crucial to assess air quality after such changes.
• Unexplained allergies or symptoms: If you or your household members suddenly get respiratory issues or allergies without a clear cause, it could be due to pollutants or allergens in the air.
• After big environmental events: Wildfires, flooding, and extreme weather changes can impact indoor air quality as well. Make sure you test your IAQ in case anything like this happens.
• As part of routine maintenance: It’s a good idea to periodically test your indoor air quality based on your needs and goals. This kind of testing allows you to identify potential issues early, helping you address them before they lead to any negative health impacts.

Six Major Indoor Air Pollutants

Indoor air pollution is a silent but deadly problem, contributing to 3.2 million premature deaths worldwide each year. Testing your home’s air quality can reveal hidden pollutants that may pose serious health risks, such as:

• Radon: A radioactive gas that seeps into homes from the ground, radon is the second leading cause of lung cancer globally.
• Carbon Monoxide (CO): This odorless and colorless gas results from incomplete combustion in appliances like stoves or heaters and can be fatal even at low levels.
• Particulate Matter (PM): Tiny particles are categorized by size—PM1, PM2.5, and PM10—and often come from smoke and dust. The number represents the particle's diameter in micrometers. Smaller particles can penetrate deeper into the lungs and bloodstream, causing respiratory and cardiovascular problems.
• Formaldehyde: This colorless gas is found in many household products, including furniture and building materials, and can irritate the eyes, nose, and throat, as well as long-term health issues like cancer.
• Volatile Organic Compounds (VOCs): Emitted by everyday household products like paints, furniture, and cleaning supplies, VOCs can irritate the eyes, nose, and throat and may have long-term health effects.
• High Humidity: Excess moisture creates an ideal environment for mold growth, which can trigger allergies, asthma, and other respiratory conditions.

How to Test Air Quality in Your Home

How you test the air quality in your home will depend on the specific pollutant you are checking for. To get a broader picture of several toxic substances present in your home air, the best option is to choose air quality monitoring devices. However, some pollutants require more comprehensive testing, which can be done only by a team of professionals. 

In this section, we’ll help you decide which air quality testing method is right for you and explain how to test for specific pollutants individually.

An indoor air quality monitor is the simplest way to check your home’s air quality. This device measures various pollutants depending on the model you choose. 

Low-cost indoor air pollution monitors usually track volatile organic compounds (VOCs), particulate matter (PM), carbon monoxide (CO), formaldehyde, humidity, and temperature. 

Air quality monitors are great because they not only show you the air quality in your home but also help you spot patterns so you can act accordingly. For instance, the device might show higher VOC levels after cleaning, indicating that the products you're using release too many harmful substances. In this case, consider using healthier alternatives and improving ventilation while cleaning.

IAQ monitors don't detect mold spores, but we'll cover mold testing in the next section of this article. However, these devices can detect high humidity levels, which may indicate conditions that are ideal for mold growth.

There are two main types of AQ monitors, consumer-grade and professional-grade monitors. Both can measure one or more pollutants. 

Consumer-grade monitors are designed for everyday use. They come in two main varieties:

• Portable monitors, such as Atmotube PRO, are ideal for checking air quality in different locations, allowing you to map out the areas with high air pollution. They can also be used as stationary devices. Another use case is testing outdoor air pollution, and then checking indoor air quality to determine whether the pollution from outside has penetrated your home. This can also help you see how well your air filtration systems and air purifiers work.

• Stationary monitors, such as those from Airthings, are designed to stay in one place. These devices can give you consistent results and air pollution trends in one place, such as your kitchen or living room, so you can identify what affects the air. If you want to test air quality throughout the house, you need to move it between the rooms keeping it plugged in.

Professional-grade monitors, like GrayWolf or Particle Plus, are stationary devices used by environmental professionals mostly. They offer high precision and detailed insights, which makes them ideal for industrial, commercial, or research purposes. However, they might need periodical calibration due to exposure to different weather conditions.

The first thing you need to pay attention to is placing your monitor in the right spot. You’ll want to place it in the room where you suspect air pollution is present. For example, your basement or bathroom due to mold suspicion. You can also check the air quality of the rooms where you spend most of your time, such as your living room or bedroom, and see if there are any toxic particles present. 

Regular maintenance is equally crucial for reliable results. This includes checking for and installing software updates, as manufacturers often release improvements to enhance accuracy. While most consumer-grade monitors feature automatic calibration, professional-grade devices may require periodic manual calibration to maintain precision. Always follow the manufacturer’s guidelines to ensure the monitor continues to provide accurate and actionable insights.

For example, one Atmotube PRO user in Cambridge, UK, started noticing a spike in PM2.5 levels when using the kitchen extractor. After reviewing their air quality data over time, they realized that outdoor smoke was being pulled inside due to negative air pressure from their unused chimney. Once they identified the issue, they sealed the chimney and improved ventilation, which significantly improved their indoor air quality.

Compare the results to the recommended safe levels of various pollutants and take action when necessary. 

You can find a table to help interpret your PM results here (Particulate Matter) and your TVOC results here (Total Volatile Organic Compounds).

If you or someone in your household is experiencing headaches, allergies, or respiratory issues with no obvious cause, it’s a good idea to seek professional help. Professional testing is also essential if you suspect the presence of asbestos, lead, or other harmful substances. Additionally, if DIY tests provide unclear or inconsistent results, reaching out to an expert is the best step.

What do professionals offer?

• Comprehensive IAQ testing: Professionals can analyze a wide range of pollutants that are difficult to detect with DIY kits, such as mold and radon.
• Precise diagnosis: Using specialized instruments, they can pinpoint specific problem areas, such as hidden mold growth, high radon levels, or sources of chemical emissions.
• Tailored solutions: Professionals provide actionable recommendations, from improving ventilation and sealing cracks to installing air filtration systems or radon mitigation devices.
• Health and safety assurance: Their expertise ensures pollutants are measured and addressed accurately, minimizing health risks and providing peace of mind.

To keep your home safe, it’s important to regularly monitor air quality, even after a professional inspection. Small changes in weather or household conditions can still affect pollutant levels over time.

Testing for mold in your home is important because it can be a serious health risk. Studies show that long-term exposure to mold or dampness in the home increases the risk of asthma by 50%. The problem is that mold often grows in hidden areas like basements, bathrooms, or behind walls, making it harder to spot.

That's why it's a good idea to test for mold if you notice a musty smell or see mold patches, even if they're small.

How to Run a Mold Test

If you want to quickly check for mold, DIY mold testing kits can be helpful. However, these kits have some limitations. They can tell you if mold is present, but they won't identify the type of mold, its toxicity, or where it's coming from.

To perform more detailed mold testing, you should consider hiring mold experts.

Professional environmental testing companies use advanced tools and microbial testing to give you a clearer picture of the mold situation in your home. With their help, you'll find out:

• If mold is present
• Where is the moisture coming from
• If your health is at risk

Hiring mold experts is important because they can help prevent mold from spreading, which can happen quickly. This is especially necessary if you've had water damage or have been dealing with ongoing mold issues.

How to Properly Mitigate Mold

According to the EPA (Environmental Protection Agency), if the affected area is less than about 10 square feet, you can remove the mold by yourself. 

This is how:

• Lower humidity levels in the room by using a dehumidifier, fans, or exhaust systems.
• Fix any leaks from pipes, roofs, and appliances.
• Use hydrogen peroxide and liquid soap mix to spray the affected areas and let it sit for a couple of minutes. Avoid using bleach as it will only discolorate the mold without removing it.
• Wear an N-95 mask, put on old clothes that you can throw away, and cover all body parts when removing the mold.
• To avoid mold appearing in the first place, use mold-repellant materials when renovating your apartment.

Carbon monoxide is considered to be a silent killer because you can’t see it or smell it. Yes, you can catch early symptoms of carbon monoxide poisoning, such as headaches, dizziness, and confusion, but they are not specific enough to make you suspect there is a leak. If the poisoning continues, it can even lead to fatal outcomes. That’s why it’s safest to rely on a carbon monoxide detector when checking for its presence in your home.

Where does it come from?

Carbon monoxide comes from carbon fuels with incomplete combustion. For example, gas, wood, gasoline, or charcoal from different stoves or heaters can pose a serious risk of carbon monoxide poisoning.

As we mentioned before, the best and safest way to check for carbon monoxide in your home is by using a CO detector. These devices are convenient and easy to install in your home, similar to smoke detectors. Our advice is to place them near the sleeping areas, or ideally on each floor of your home for maximum safety.

However, keep in mind that most of these devices are battery-operated, which means that you’ll have to check and replace batteries regularly.

Radon is a radioactive gas that forms when uranium, thorium, or radium break down in the earth. Because it is found in the ground, it usually enters your home through any open or cracked space in the foundation. 

To demonstrate how seriously poisonous this gas can be, there is a statistic that says radon is responsible for 21,000 lung cancer deaths every year in the US alone. Given the fact that it is colorless, odorless, and tasteless, it’s important to test your home with the help of a professional if you’ve never tested it before or just moved into a new home.

Radon can be tested either using DIY test kits, radon monitors (such as Airthings device), or with the help of a professional. 

For DIY radon testing, there are two options: 

• Short-term radon testing kits: If you want to quickly check radon levels in your home, short-term kits can give you results in just a few days. These kits measure radon for two to seven days, and once the test is complete, you send it to a lab for analysis. However, since radon levels can fluctuate depending on the time of the year, these tests may not show you accurate readings of your long-term exposure.
• Long-term radon testing kits: These kits will give you a more complete picture of radon exposure in your home. They measure radon levels over several months (minimum is 90 days), which allows them to capture changes over time before being sent to a lab for analysis. If you're serious about reducing radon levels across all conditions, long-term kits are a more reliable choice.

Radon levels can vary daily or seasonally, so a short-term test might miss spikes and falsely indicate the air is safe. In fact, a study shows these tests fail to predict seasonal changes in 96% of cases. Therefore, using long-term tests will give you more accurate results.

If you want reliable results without the risk of errors, we advise you to hire a professional radon tester. The testing crew uses specialized equipment that can measure radon levels with more precision than DIY kits. 

If you opt to check radon levels yourself, you should know that they are measured in picocuries per liter of air (pCi/L). The EPA recommends hiring a licensed professional to reduce radon levels if they are at or above 4 pCi/L.

How to Use Air Purifiers to Improve Indoor Air Quality

Air purifiers can help you reduce some indoor air pollutants, such as particulate matter (PM), allergens, pet dander, volatile organic compounds (VOCs), and household odors. 

You can choose air purifiers with different filters, each effective for different air pollutants:

• HEPA filters remove at least 99.97% of fine particles, including dust, pollen, mold spores, and pet dander.
• Activated carbon filters are good at absorbing VOCs, cigarette smoke, and common household odors.
• UV-C light is used for targeting airborne bacteria, viruses, and mold spores by disrupting their DNA.
• Hybrid models are devices that combine filters for more efficient air pollution removal.

The most reliable way to keep your home's air safe and clean is by combining air purifiers with air quality monitors. Monitors provide insight into air quality before and after, while purifiers ensure most pollutants are removed.

As we mentioned before, many pollutants are hard to distinguish; so instead of looking for symptoms, make sure you use a verified device to see if any harmful particles are left after purifying the air.

Testing your home's air quality is not just a precaution—it's an essential step toward creating a safer, healthier living environment. Start small with IAQ monitors for daily insights, and move to specific tests for pollutants like mold, radon, and carbon monoxide when necessary.

When in doubt, don’t hesitate to bring in professionals. They offer the precision and expertise needed to identify and mitigate issues that DIY solutions may miss. Whether it’s pinpointing the source of mold, installing a radon reduction system, or improving overall IAQ, their guidance can make all the difference.

Protecting your home’s air quality isn’t a one-time effort—it’s an ongoing process. Regular monitoring and proactive measures can help you stay ahead of potential problems, ensuring that your home truly supports your health and well-being.