The other aspect is indoor air quality. Although it’s not talked about as often, and in developed countries, it’s often completely overlooked, indoor air quality is as important, if not more so than outdoor air quality.
We spend as much as 90% of our time indoors. Even if you work outdoors, it is likely you spend at least 60% of your time indoors. This is an incredible amount of time and makes me wonder how indoor air pollution is so often overlooked - we live indoors, yet we generally aren’t worried about the air we breathe.
Although we’ve largely focused on outdoor air pollution on AirPop Health so far, today, we want to take a look at indoor air pollution. It impacts many of us more than outdoor air pollution, but it’s a topic with far less coverage.
In this article, we will first examine the pollutants that make up indoor air pollution and their health impacts. Moving on from this, we will discuss common sources of indoor air pollution and how you can improve air quality in your home, office, and other indoor spaces.
Indoor Air Pollutants to be Wary Of
There is a large range of indoor air pollutants that can impact your health, and we can’t cover them all in this section. However, we will be discussing the most common air pollutants you should keep an eye on.
At first, you may not think carbon dioxide is a pollutant - after all, we exhale carbon dioxide, so surely it can’t be bad? Well, at normal levels, it’s not. When the carbon dioxide concentration is less than 800 ppm (0.08% of the air), it has minimal impact on our bodies and minds.
However, carbon dioxide quickly climbs above this concentration in confined environments, especially when there are multiple people. I’ve seen concentrations as high as 4000 ppm in my unventilated bedroom when I wake up! Concentrations this high greatly impact not only our bodies but, more importantly, our minds.
We’ve written a separate article detailing the dangers of carbon dioxide, and we recommend reading that for further information. However, in short, carbon dioxide greatly lowers our cognitive performance and hinders our productivity.
Carbon dioxide impacts our brains so greatly that at only 1400ppm, our cognitive performance is halved. Furthermore, you’ll feel drowsy, especially in the mornings. At high concentrations, you may also begin to experience headaches and more.
Although carbon dioxide doesn't have long term health impacts (except at exceptionally high concentrations), it's important to keep an eye on it for two reasons. Firstly, it can greatly impact how you feel in your day to day life. If you regularly feel drowsy, or like you can't concentrate, it could be due to high carbon dioxide concentrations.
Secondly, monitoring carbon dioxide is a great way to judge ventilation. Since CO2 concentrations drop in rooms with better ventilation, monitoring CO2 can allow you to judge how well ventilated a room is and whether you need to open a window or door.
Sources: Carbon dioxide is exhaled by humans and animals. Therefore, while you can’t prevent carbon dioxide from being created at the source, you will instead need to ensure adequate ventilation so the air is regularly cycling and fresh air is replacing the CO2-rich air.
Carbon monoxide is probably the most dangerous pollutant on this list; carbon monoxide can have very serious health consequences and even lead to death. While most modern homes are free from carbon monoxide, there are times when you will want to be wary of this extremely dangerous gas.
Carbon monoxide is produced whenever something burns - whether smoke from an indoor fireplace, some food burning, or a car is started in an adjacent garage. What many people don’t consider, however, is that carbon monoxide can also be produced by devices such as clothes dryers and water heaters.
For this reason, it’s important to ensure there is ventilation in your home whenever there is a fire or smoke present. If you’re cooking, make sure to open some nearby windows. If you have an indoor fireplace or wood burner, try to provide ventilation to prevent the dangers of escaped smoke.
Finally, if you have a garage attached to your house, ensure that the door between your home and garage is closed when starting any vehicles or machinery. You want to avoid carbon monoxide entering your home whenever possible! Furthermore, ensure your garage door is open and ample ventilation is present in the garage.
Sources: Carbon monoxide is produced whenever something burns. If there is smoke, there is also carbon monoxide. This means it is produced by cooking, fireplaces and wood burners, machinery, and vehicles.
Volatile Organic Compounds (VOCs) are a category of air pollutants which are primarily found indoors. Some more commonly known VOCs are acetone, benzene, ethylene, formaldehyde and xylene.
VOCs are a big issue indoors because they are emitted from a range of chemical products often used in homes and offices. Products such as air fresheners, insect spray, nail polish, and fuels are big sources of VOCs.
Since many homes are not well-ventilated, VOCs can quickly reach hazardous concentrations. In fact, it’s not uncommon for VOCs to be 10x more concentrated indoors. If you’re doing certain activities, such as paint stripping, VOC levels may even be 1000x times higher indoors!
While measuring each VOC individually is next to impossible, you will often encounter the term tVOC. This stands for total volatile organic compounds and is a measurement usually in ppm (parts per million), representing the total number of VOC particles in the air.
Sources: VOCs are emitted from various products and processes using chemicals. Common sources of VOCs are aerosol sprays such as insect repellants and air fresheners, nail polish, paint removers, and more.
Particulate Matter (PM1, PM2.5, PM10)
A form of pollution which is often talked about in the context of outdoor air pollution is particulate matter, such as PM2.5 and PM10. Both of these forms of pollution are also dangerous when indoors, and it’s important to control the levels of both whenever possible.
While particulate matter is a broad category, it’s often broken down into PM1, PM2.5 and PM10. Each of these classifications indicates the particle size - PM1 is particles smaller than one micrometre, PM2.5 is particles smaller than 2.5 micrometres, and PM10 is particles smaller than 10 micrometres.
Although each of these particles can be harmful, PM1 and PM2.5 are generally considered more dangerous. This is due to the fact they can easily enter the human body and reach our organs - especially in the case of PM1.
As such, it’s important to minimise the levels of these particles as much as possible. However, where do they come from? Well, indoor particulate matter most commonly comes from smoke. If you have an indoor fireplace, regularly cook, or have any other source of smoke, you’ll likely see your particulate levels soar.
It's also important to consider that fine particles can enter your home from outdoors. If you live a large city, this is especially common. To check if you should be closing your windows, you can monitor the local air quality index (AQI) on a range of apps and websites. When the air quality reaches hazardous levels, you'll want to consider closing your doors and windows and running an air purifier.
Sources: Particulate matter is most commonly emitted by smoke; therefore, any sources of smoke indoors will lead to increased particulates. If you are cooking or have an indoor fireplace, ensure adequate ventilation. Furthermore, particulate matter can enter your home from outdoors if the pollution outside is severe.
Mould spores are another pollutant which is often more concentrated indoors than out. While some forms of mould are relatively harmless, there are also very dangerous types of mould which can have adverse health effects. Since it is hard to tell which mould is which, the best way to approach the issue is to remove all mould and prevent it from growing in your home.
Mould grows in damp, dark environments - unfortunately, these conditions are present in many homes. To grow, all mould needs is ‘food’ such as dust, books, paint, wallpaper, carpets, or otherwise. Before you know it, mould can spread, and its spores can significantly degrade indoor air quality.
While different types of mould will impact different people in varying ways, it’s estimated that 10% of the population is severely allergic to mould. The symptoms of these allergies can be respiratory problems, nasal and sinus congestion, a sore throat, coughing, and more. All in all, the best approach to mould is to remove it entirely.
Sources: Mould grows in damp, dark places with organic materials such as wallpaper, carpet, or otherwise
How You Can Improve Your Indoor Air Quality
As we hope you are now aware, indoor air quality isn’t something that should be overlooked. Even if you feel indoor air pollution isn’t an issue in your home, you might be surprised! Before taking action, I never felt like it was an issue in my home. However, after improving the air quality indoors I quickly realized that for years, poor indoor air quality had been triggering my asthma!
However, what steps can you take to improve your indoor air quality? After all, if we can’t even monitor our air quality, it’s hard to know what actions we can take and if they’re even needed! Well, let’s take a look at the best ways to ensure your home is safe!
Monitor Your Air
You may be surprised to know, but many devices on the market allow users to monitor their indoor air quality. While the devices vary greatly in price, features, and monitored pollutants, inexpensive options are available online.
Indoor air quality monitors will measure either one or a combination of tVOCs, PM2.5, PM10, and carbon dioxide. Even better, some monitors will allow you to view the levels of each pollutant on your smartphone or computer, making them extremely convenient to use.
While these devices may not seem essential, they are incredibly useful tools for identifying where and what air quality issues exist in your home (or any indoor location!). Without a monitor, it’s hard to know exactly which pollutants you might be dealing with and how severe the problem is.
However, with an indoor air quality monitor, you can quickly identify pollution sources in your home and act accordingly. Furthermore, devices such as carbon dioxide detectors will let you know when you need ventilation in your home and even when there is a high chance of viruses spreading!
The mentions of ventilation in this article might be getting repetitive by this point, but that’s because ventilation is your single best tool against indoor air pollution. Provided you are in an environment with clean outdoor air, simply opening your doors or windows can significantly lower carbon dioxide and VOC concentrations!
You might want to consider an HVAC system with HEPA filters if you are in a heavily urbanised area or elsewhere with significant outdoor air pollution levels. These can provide ventilation while also filtering air that passes through.
Whichever option you choose, ensure you regularly ventilate your home to keep the air quality as pristine as possible. Even in winter and colder months, try to ventilate whenever conditions allow for it.
Monitor and Manage Humidity
Many people don’t know that there is a ‘perfect’ level of humidity in which viruses, bacteria, fungi, and more are at their least effective. The Sterling Chart represents this phenomenon, and it shows that between 40 and 60% relative humidity, all of these pollutants are at their lowest concentrations and effects.
While it can be hard to maintain humidity in this range depending on where you live, we have a range of tools that allow us to manage humidity in our homes. Dehumidifiers are a great way to remove humidity (and they are very effective against mould!), while humidifiers greatly increase humidity in dry climates.
Unfortunately, without a relative humidity monitor, it can be hard to tell what action you might need to take, if any. Luckily, many indoor air pollution monitors and carbon dioxide monitors include relative humidity sensors. Depending on the dehumidifier you purchase, it may have a humidity sensor built-in.
Regardless of how you choose to monitor your relative humidity, it’s an important task to do. Besides ventilation, there is no better way to ensure the air in your home remains healthy and clean, and we recommend taking action against humidity wherever possible.
Remove Pollutant Sources
The best way to manage pollutants which are created within your home is to remove the sources that create them. However, this isn’t always possible - for example, it’s unrealistic to stop cooking altogether just to avoid PM2.5. In these cases, you can’t remove the source and are better off minimising the pollutants involved.
When doing this, it’s important to ensure there is enough ventilation so that emitted particles can either be filtered or removed. For example, if you have an extraction fan above your oven, use that whenever cooking. If not, make sure to open windows in and around your kitchen.
The same goes for more potent pollution sources, too - for example, if you need to paint a room, ensure there is enough ventilation for the fumes and VOCs to escape outside. In these cases, you’ll also want to avoid breathing air whenever in the room, and investing in a painting mask is a good idea.
For some other sources of pollutants, it’s possible to remove them entirely. If you have an automatic insect spray device, you may want to consider replacing it with a non-airborne alternative. While these devices are super handy for keeping insects out, they emit many VOCs!
Regardless of what pollutant you are trying to minimise, removing the sources that produce them is a great first step. Unfortunately, it’s not always possible, and minimising their impact is key in these cases.
Prevent Ambient Pollution From Entering From Outside
At times, outdoor air pollution will be worse than indoors. This is especially true if you live in a wildfire-prone area or somewhere that experiences fine seasonal dust due to weather patterns. Whatever the situation, it’s important to ensure this particle-filled air is not entering your home and is staying outside.
To know when you’ll want to ‘lock down’ your home, it’s important to keep an eye on local air quality. This can be done in a range of different apps and websites, and you should be able to find a monitor within a few kilometres of where you live.
These monitors provide a general reading of outdoor air pollution and usually measure particulate matter such as PM2.5 and PM10. Some more modern monitors will also measure other pollutants, but these are less common.
If you see the AQI recorded by these monitors surpassing ‘hazardous’ levels, it’s time to close your windows and doors. This will prevent unclean air from entering your home and ensure your inside air stays healthy.
If you have an air purifier, this is the time to use it. Since bringing in more air from outdoors is potentially harmful, air purifiers are at their most useful when doors and windows aren’t the easy answer for ventilation.
Use an Air Purifier
That leads us to our final point for improving your indoor air quality! Using an air purifier. Now, it’s important to note that not all air purifiers are created equal, and some vastly outperform others. Furthermore, air purifiers are not a replacement for ventilation.
With that said, air purifiers do have their place, and they can be extremely useful when it’s not possible to ventilate your house (such as during the cold winter months). Air purifiers will clean the particulate matter in your air and are effective at removing mould spores and fungi.
To use your air purifier as effectively as possible, ensure that it has a CADR (clean air delivery rate) adequate to keep the room it’s used in clean. Furthermore, you’ll want to gradually move the purifier around to different rooms to ensure every room benefits from its air-cleaning properties.
Although we spend most of our time focusing on outdoor air quality, indoor air quality is as important, if not more important. Not only does indoor air quality impact us in different ways, but we spend 90% of our time indoors on average!
Thankfully, while we don’t have control over outdoor air quality, we can improve our indoor air quality through a few simple steps. By being aware of potential air quality issues, we can take steps to avoid them and ensure our air is clean and healthy.
If you want to learn more about your air quality, we recommend picking up an air quality monitor. A carbon dioxide monitor is incredibly useful if you want to test ventilation. These monitors will allow you to see into a world you couldn’t see before!
However, whether you decide to use an air quality monitor or not, it's important to at least be aware of the dangers that indoor air pollution poses. If you can control pollution at its source - or at least decrease pollutants before they reach dangers concentrations - you will be able to live a far healthier life.