What is Indoor Air Quality (IAQ), and How Does it Impact You?
What is IAQ?
Indoor Air Quality (IAQ) refers to the air quality within and around buildings, and its impact on the health and comfort of the building’s occupants. According to OSHA, IAQ can include “temperature, humidity, lack of outside air (poor ventilation), mold from water damage, or exposure to other chemicals.” Although IAQ has long been regarded as an important topic with OSHA and the EPA, IAQ has recently seen more press coverage than ever because of the COVID-19 pandemic and people seeking a solution to keep them safe.
Frequently asked questions about IAQ that usually come up include understanding what causes IAQ, effects on health, and ways that you can improve IAQ in your workplace or home.
What are Common Causes of Poor IAQ?
Indoor Pollution Sources
One of the biggest causes of poor IAQ is indoor pollution. Indoor pollution sources can impact IAQ by releasing gases or particles into the air.
Examples of indoor sources of pollution include, but are not limited to, tobacco products, fuel-burning combustion appliances like space heaters, stoves, ovens, and fireplaces; building materials, household cleaning products, heating and cooling systems, humidifiers, high moisture levels, and incoming pollutants from outside like radon, pesticides, etc.
How important a source is in its impacts on IAQ is dependent on the concentration of pollutants that it emits over time, and the hazard level of the pollutants. Sometimes the age of the pollution source and its maintenance can also be a contributing factor as well.
Some pollutant sources, like building materials, release pollutants at a pretty consistent rate. On the other hand, some sources are based on activities like smoking or cleaning, and thus intermittently release pollutants into the air. In some scenarios, appliances or other indoor products malfunction or are not vented properly, releasing higher than normal concentrations of pollutants inside.
Once emitted into the air, each pollutant type can vary in how long it lingers in the air. Some can last for long periods even after the activity that produced them has stopped.
Temperature and Humidity Levels
High temperature and humidity levels can also increase concentrations of some pollutants. Many strains of bacteria and viruses do best in high or low levels of humidity, while mold thrives in places where humidity levels are higher. Mold growth occurs frequently in schools, especially during summer break when cooling mechanisms are not usually running and carpet cleaning is usually taking place, leading to higher moisture in the building. Concentrations of dangerous pollutants like ozone and formaldehyde change directly with a change in humidity. In regard to temperature and IAQ, higher temperatures are preferred by bacteria and viruses, and thus a higher pathogen count is found in spaces that are warmer. Furthermore, higher temps speed up chemical reactions, leading to higher production levels of ozone and other hazardous compounds. Warmer temperatures also increase emissions of VOCs, a group of compounds that can be particularly dangerous for human health.
Inadequate Ventilation
A poorly ventilated building can cause indoor air pollutants like those mentioned in the above section to reach even higher concentration levels over time. Outdoor ventilation helps to diminish the concentrations of the pollutants in the air by adding additional air into the space, and without incoming air, the pollutant levels become more and more concentrated over time, making the space more hazardous for you.
Indoor Air Quality & Its Impact on Health
Short-Term Effects on Health
Upon exposure to certain pollutants, health effects like irritation of the upper respiratory tract (eyes, nose, and throat) may frequently be observed. Other immediate effects include headaches, nausea, and tiredness. Oftentimes, these health effects are short-term and can be helped by treatment, which might include eliminating exposure to the pollution source. Sometimes health effects can worsen over time from continued exposure, like asthma.
The chances of experiencing immediate health impacts from poor indoor air quality is dependent on a few factors. These include your age and whether or not you have any pre-existing medical conditions that may make you more predisposed. Sometimes, your reaction to an exposure might be due to your individual sensitivity, which might be different from another person’s. In fact, some individuals become more sensitized to pollutants after an exposure, especially if it was repeated or one at a high level.
Short-term health effects are often likened to that of colds or other common symptoms of viral diseases, so it can be challenging to identify if the cause is viral, especially during the winter months when transmission is typically higher, or if it is truly from the IAQ. To better determine if your symptoms are due to IAQ, record the time and location of when your symptoms occur. If you feel better or symptom-free when away from an area, possible indoor air pollutant sources may be able to be identified and addressed. It could be a problem that is being made worse by poor ventilation or air flow, or even from inappropriate humidity or temperature levels.
Long-Term Effects on Health
Aside from short-term health effects, poor IAQ can have a long-term impact on your health. In fact, you might not see any impact on your health until years after exposure has already occurred. These health effects may include certain respiratory diseases, heart diseases, cancer, and diseases affecting the nervous system. Some of these may cause severe debilitation or even death. Much is still unknown about what concentrations or time exposure is needed to produce these health issues. However, you can help to prevent these long-term health issues by employing strategies meant to help improve IAQ.
How Can You Improve IAQ in Your Workplace or Home?
Portable HEPA air purifier keeping the workspace safe at a credit union.
Good IAQ can be achieved by maintaining an indoor space that is kept at a temperature that is comfortable and maintaining a humidity level between 30-50%, as well as using the three basic strategies below.
There are three basic strategies to improve indoor air quality:
Control or Eliminate the Pollutant Source
Improve Ventilation
Use Portable Air Purifiers
Control or Eliminate the Pollutant Source
Controlling or eliminating the source of pollution is usually the most effective way to improve IAQ.
In some situations, the pollutant source can be sealed or encapsulated. A typical example of this would be in dealing with asbestos. In other situations, like for appliances such as a gas stove, decreased emissions can be achieved by the appliance being adjusted. Controlling pollutant concentrations is often the most cost-effective approach to improving IAQ versus improving ventilation. Improving ventilation often requires a complete overhaul of the existing HVAC system or retrofitting the HVAC system to be able to handle a more powerful MERV filter. To do either of these would require significant funding in the realm of hundreds of thousands of dollars. This is not achievable by many building or home owners. Increasing ventilation by adding more outdoor isn’t a perfect solution either, as it can dramatically increase energy costs, plus outdoor air is not always safe to breathe either.
Improve Ventilation
Another possible strategy is improving your building’s ventilation. Many buildings’ heating and cooling systems, which includes forced air heating systems, do not necessarily bring fresh outdoor air inside. A way to help bring more outdoor air in would be to open windows and doors, using fans, and if the weather allows, using a window air conditioner with the vent control open so as to increase the outdoor ventilation rate.
If you know that you are going to be involved in a short-term activity that is an indoor pollution source, such as cooking, painting, or doing a hobby that emits pollutants, increasing ventilation prior to engaging in the activity is one of the most helpful things you can do to maintain good IAQ. Skipping the increased ventilation step and just doing the activity outdoors might even be the better option if the weather is suitable.
Keeping in mind the role that high temperatures have on IAQ, increasing ventilation and shading can help keep indoor temperatures lower. Increasing ventilation can also help to move indoor pollutants out of the space, or lessen their concentration.
Although ventilation is often regarded as a potential strategy for improving IAQ, be careful when increasing the concentration of incoming outside air, as your outdoor air might not be suitable to breathe. Consider if there are nearby sources of outdoor pollutants like factories or smoke. Ventilation should especially not be increased on days when an air quality alert has been issued for your area. Aside from outdoor air not always being suitable to breathe, proper ventilation is not always guaranteed because desired air flow might not achieved on certain days due to wind direction and speed. Furthermore, depending on the season, opening up doors and windows might not even be an option.
Use Portable Air Purifiers
Using a portable air purifier or air cleaner will help to improve IAQ when selected correctly for your space. There is a wide variety of air purifier products on the market, ranging from inexpensive table-top models to the high-quality, long-lasting commercial-grade models. Portable air purification would prevent a retrofitting of an existing HVAC system, making it a cost-friendly option for businesses, schools, and homes. However, some air purifiers are highly effective at particle removal, while others, including most table-top models, are much less so, making it vital to do some preliminary research on which model would be best for you and your IAQ goals.
The effectiveness level of an air purifier depends on how efficient it is at collecting indoor air pollutants AND how much air the purifier can pull through the filtering system. This measure is known as cubic feet per minute (CFM).
Even if an air purifier is highly efficient at collecting air pollutants, it will not be effective if it has a low CFM value. Same goes for a model that has a high CFM but is inefficient at collecting pollutants. Furthermore, many people when investigating an appropriate air purifier for their space forget to consider maintenance. Continued performance and effectiveness of an air purifier depends on maintaining it according to the manufacturer's directions. This can quickly become time-consuming, high costs for frequent filter replacement, or even just forgotten about, leading to poor IAQ over time even though you have air purifiers in place. Another important factor in determining the ability of an air purifier to combat poor IAQ is the strength of the pollutant source and if there is a high concentration of pollutants being emitted. In scenarios with high emissions, table-top air purifiers will likely be unsatisfactory in removing enough pollutants to provide the IAQ you are looking for.
Air purifiers can be the most cost-effective and highly efficient way to control indoor pollutant levels, including germs such as viruses. Air cleaners have been specifically designed to filter pollutants or contaminants out of the air, and are not dependent on the weather like ventilation or on identifying a pollutant source.
Ultimately, air purifiers are most often the ideal solution to achieving IAQ goals for any location, whether it be schools, businesses, or residences/homes.
