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Indoor Air Quality: The Property Manager's Guide

When we think about the role of a commercial property manager, indoor air quality should immediately come to mind. More often than not, though, air quality only comes up as an afterthought or in response to a tenant complaint.As we learn more about the effects of air quality in offices, quality tenants are starting to demand a proactive approach to indoor air pollution. Poor air quality can result in anything from mild discomfort to acute or chronic illnesses. These factors make the building less pleasant to be in and cost employers money. Almost as important for business tenants is the measured decrease in worker productivity that results from stale indoor air.[caption id="attachment_2830" align="alignright" width="300"]

Portrait of businesswoman sitting in an office with high indoor air quality

Indoor air quality has a strong correlation with productivity.[/caption]People spend 90 percent of their time indoors, breathing air that is often stale or contaminated by trace pollutants. For a large company, the costs of even a small decline in average performance due to high CO2 levels or to an increase in sick days are very significant. Proactive measures that result in a superior quality of indoor air aren’t just a way to avoid complaints anymore; they’re a way of attracting new and better tenants. Think, “museum-quality indoor air.” Clean indoor air is also an important component of building scoring mechanisms like the WELL Certification.The Property Manager's Guide To Indoor Air Quality is designed to serve as a reference for the most common health risks of poor indoor air quality, what causes them, and what you can do to fix them. Know something we don't or have a problem we aren't addressing? Let us know at Marketing(at)Aquicore.com.

Table of Contents
Symptoms and Illnesses Caused by Poor Indoor Air Quality

One of the most challenging aspects of managing indoor air quality in commercial spaces is that the effects of air pollutants are often vague and vary person to person. This makes the source of a problem equally difficult to pin down. Reactions range all over the spectrum, depending on personal sensitivity, building zone, and even time of day.[caption id="attachment_2831" align="alignleft" width="300"]

Young businessman feeling unwell in the office.

Sick building syndrome can cause discomfort or more serious symptoms.[/caption]

Sick Building Syndrome

One of the most well-known illnesses caused by indoor air pollution is sick building syndrome (SBS). This is a catch-all term for symptoms that some residents or employees feel when they're inside a particular building. Sick building syndrome has been tested and is generally accepted as a legitimate phenomenon. However, an important feature of it is that tests reveal no clear medical issues or cause.The most common symptoms of SBS include lethargy, headache, nausea, difficulty concentrating, and irritation of the respiratory system or skin. In particular, sick building syndrome is suspected if symptoms go away upon leaving the building, if there is a particular part of the building that causes symptoms, or if more than one person is experiencing the symptoms. Sick building syndrome can also be seasonal, indicating an issue related to heating and cooling.

Building Related Illness

In contrast to sick building syndrome, building related illnesses are diagnosable illnesses that are caused by indoor air pollution of some kind. Generally, though not always, building related illnesses are caused by biological contaminants. Some of the most common building related illnesses are Legionnaires’ disease, humidifier fever, and hypersensitivity pneumonitis, according to the EPA.Building related illness is a more serious concern than sick building syndrome, both in terms of health risk and legal liability. Employees that contract a building related illness as a result of poor indoor air quality, particularly a serious or chronic illness, may be eligible to sue for compensation.

Multiple Chemical Sensitivity

The EPA also mentions the disputed chronic medical condition known as multiple chemical sensitivity. MCS causes individuals to have acute reactions to levels of chemical exposure that are safe in other people. Like sick building syndrome, tests are unable to identify anything medically wrong that would cause the symptoms the patient is experiencing. The symptoms tend to be relatively similar as well. Unlike sick building syndrome, MCS symptoms are as likely to be triggered by a placebo as they are by the chemical(s) in questions, and as a result, this disorder is probably psychosomatic.Unfortunately, MCS sufferers are unlikely to be satisfied with property managers who tell them that their condition isn’t related to actual environmental factors, especially because their symptoms are all too real. Research suggests that strong smells are the most common triggers, though simply knowing that a chemical is being used may result in symptoms. Changing the cleaning routine for these tenants’ areas and increasing ventilation may help to satisfy them.


[caption id="attachment_2833" align="alignright" width="300"]

A sloth stops to pose for a photograph in Costa Rica.

It's not just you - CO2 causes lethargy in meetings.[/caption]One of the most common and most infrequently noticed results of poor indoor air quality is lethargy. When carbon dioxide builds up in a room with insufficient ventilation - in a crowded meeting, say - people begin to feel sleepy. Research indicates that high levels of CO2 cause an 8 to 13 percent decrease in cognitive function, which causes lower worker productivity.CO2 concentration is usually between 250 and 350 ppm in rural areas and between 350 and 550 ppm in cities. The EPA believes that a concentration of above 700 ppm is unhealthy for people. In heavily-used conference spaces, CO2 can reach upward of 1,500 ppm.While rare in commercial buildings, lethargy can also be a sign of harmful quantities of carbon monoxide.


Indoor air quality is also a common cause of simple, run-of-the-mill discomfort. Tenants tend to blame discomfort on the factors they’re comfortable discussing - temperature and humidity - but the real cause sometimes comes down to indoor air quality. The EPA claims that tenants who complain about the air being too dry may actually be experiencing mucous membrane irritation from particulate matter. Similarly, stale air may mean that there is a mild odor.While these complaints may not represent a threat to tenants’ health, property managers should address them promptly. Unaddressed environmental concerns can lead to decreases in employee performance or tenant satisfaction.[caption id="attachment_2832" align="alignleft" width="300"]

doctor checking at x-ray of lungs

Long-term exposure to indoor air pollution can have medical ramifications.[/caption]

Other Long-Term Effects

In particularly serious cases, indoor air contaminants can cause long-term health effects. This should be taken particularly seriously because the owner or developer of the building could be liable if they are found to be at fault. In particular, radon, asbestos, benzene, and tobacco smoke can cause cancer in building residents and users.Chronic respiratory effects are also a possibility, especially in buildings with certain types of mold or high levels of volatile organic compounds. Proper management of these factors is essential to keeping a space comfortable and safe.

Common Indoor Air Pollutants and How To Control Them
Combustion Products

Smoke should pretty much never be indoors. Whether that smoke comes from tobacco products, poorly-running furnaces and generators, or nearby traffic, combustion products produce harmful fumes that are especially problematic in an enclosed space. coming inside. (Note that CO2 and CO are also combustion products, but are listed separately.)To avoid indoor air pollution from combustion products, ensure that furnaces and generators are operating cleanly and efficiently. Pieces of large building equipment like this can release dangerous fumes when they aren't working right. Be especially vigilant about intake vents - if people are smoking near them, that smoke will be sucked in a distributed about the building. For the same reason, trucks making deliveries should not be permitted to idle their engines during unloading.

Mold and Mildew

[caption id="attachment_2834" align="alignright" width="300"]

Mold in three petri dishes

Some molds are worse for indoor air quality than others.[/caption]In sensitive people, like those with asthma, the elderly, or those with allergies, mold and mildew can cause acute respiratory effects and may be a cause of sick building syndrome. Even in the general population, exposure to mold can increase the likelihood of opportunistic infections like hypersensitivity pneumonitis. Certain types of mold can even result in long-term health concerns.In commercial buildings, mold is almost always the result of water getting somewhere that it shouldn’t or equipment that routinely gets wet failing to be cleaned. Building equipment that frequently attracts mold includes cooling towers, humidifiers, cooling coils, drain pans, duct filters, and insulation. Pay special attention to those last items - if they grow mold it will quickly spread throughout the building’s air.It’s also important to deal with any water damage promptly - waterlogged wood can start growing mold almost immediately. Finally, monitor the humidity level in your building and make sure that it stays between 25 and 50 percent.

Biological Contaminants

Apart from mold, biological contaminants like rodent droppings, insects, and dust mites can cause unpleasant odors and inflame allergies, making the building less pleasant and comfortable to inhabit. Pollen from plants is another important source of biological contamination in the spring and summer.Keeping your building free of rodents and insects is an ongoing battle in some areas, but is absolutely worthwhile. There aren’t a lot of major tenants that are willing to rent a space that overlooks an infestation. Allergy-causing contaminants can be reduced by frequently changing air filters and cleaning tenant spaces, but cannot be completely eliminated. Again, keep humidity levels between 25 and 50 percent - this will help to control dust mite populations.Bacteria and viruses are also considered biological contaminants. However, since they’re typically brought into the building by people, there isn’t much to be done apart from keeping tenant spaces clean.

Volatile Organic Compounds

Volatile organic compounds (VOCs) are organic chemicals that come from all sorts of sources. Potentially harmful substances, like cleaning supplies, pesticides, paints, and some kinds of building materials release VOCs, but so do pine trees and freshly cut roses. Not all VOCs are created equal.The ones that end up inside - at levels that are typically two to five times higher than outside - tend to be the harmful kind. Symptoms include nausea, headaches, dizziness and respiratory tract irritation, and long-term exposure can lead to cancer or damage to the liver, kidney, and central nervous system.Keeping VOC levels low is generally easier in commercial spaces than it is in residential ones. If you keep your HVAC system in good shape and consciously choose low VOC paints and cleaning supplies - especially for carpets - you will probably be just fine.

Soil Gases

Some of the most dangerous indoor air pollutants are soil gases, like radon, sewer gas, pesticides, and some VOCs. Radon, a gas that is created by the natural decay of uranium in soil, is especially hazardous to human health; it accounts for the second highest portion of lung cancer deaths every year, just behind smoking. Pesticides and sewer gases can lead to health issues, but they also cause unpleasant odors that lead to complaints.Soil gases seep in through cracks in the foundation because of the pressure differential. Basically, the building is heavy, so as it pushes down on the ground, soil gases get pushed back up. Buildings that have powerful HVAC systems are generally already pushing their soil gases up through the system and outside, where they diffuse.If testing reveals elevated levels of soil gas, you can add a sub-slab depressurization (SSD) system. This involves drilling a small hole through the foundation and installing a PVC pipe that leads outside. Even if you go this route, however, you should still get regular testing done because of the serious health hazard that high levels of radon gas present.[caption id="attachment_2835" align="alignleft" width="300"]

Illustration of the respiratory system

Particulate matter can find its way deep into the lungs.[/caption]

Particulate Matter

When outdoor air quality is discussed, especially in places like Beijing and New Delhi, the most important metric that comes up is particulate matter level. These are tiny pieces of dust, sand, and soot that get kicked into the air and find their way into people’s lungs. Particulate matter that is larger than 10 nanometers (PM10) can cause irritation of the eyes, nose, throat, and respiratory tract. Smaller particles (PM2.5) are even more dangerous. They find their way into the lungs and from there into the bloodstream, causing respiratory distress and heart problems.The most common sources of particulate matter in commercial buildings are generators, HVAC systems, and construction. Luckily, controlling particulate matter is generally straightforward. Keep anything that relies on combustion clean and in good repair and close off or ventilate any construction projects. This will help you avoid most particulate matter problems. If your building has wood burning stoves or fireplaces, be sure to maintain them properly.

Carbon Dioxide and Carbon Monoxide

Carbon dioxide and its deadlier cousin, carbon monoxide, are always present in any space at low concentrations. In enclosed spaces, carbon monoxide can be lethal, but the risk is relatively small, especially in commercial buildings where most activity takes place away from the ground floor. Property managers with properly maintained HVAC systems and CO detectors have very little to fear from carbon monoxide.On the other hand, carbon dioxide isn’t generally dangerous, but it can negatively impact tenants’ experience of the space. That nodding-off feeling in a long meeting? It’s (probably) not you - it’s the concentration of CO2. When CO2 gets above 700 parts per million, brain function goes down, people get sleepy, and less work gets done. In a busy meeting, the concentration of CO2 can easily get above 1,000 ppm. (This may or may not explain some of your coworkers’ ideas in the last meeting.)Managing carbon dioxide is tricky, but with the right investment and communications strategy, active CO2 management can become an attractive value-adding amenity. CO2 monitors in high-traffic spaces help you detect above-normal concentrations letting you increase ventilation.

Actionable Steps To Improve Indoor Air Quality

Here’s a quick recap of the steps you should take to ensure that your building’s air quality is up to par. Remember that achieving museum-quality air requires an investment in air quality monitoring hardware and a commitment to best practices. Doing this is real work, but the value that you are adding to tenants should make it worthwhile. Air as an amenity - who can argue with that?

Your Indoor Air Quality Checklist:

[caption id="attachment_2836" align="alignright" width="300"]

Green spaces inside can help to improve indoor air quality naturally.[/caption]

  • Maintain HVAC units, generators, and other combustion equipment
  • Regularly inspect and clean ductwork
  • Replace air filters on a regular schedule
  • Ensure that delivery vehicles don’t idle during drop-off
  • Prevent smoking near building entrances and air intake vents
  • Treat water damage immediately
  • Check and clean wet equipment, like humidifiers, cooling towers, drain pans, and cooling coils
  • Keep your building’s relative humidity between 25% and 50%
  • Respond to rodent or insect infestations immediately
  • Regularly deep clean carpets
  • Make use of low VOC cleaning supplies, paints, and other harsh chemicals
  • Check for radon and other soil gases and mitigate if necessary
  • Take proper steps to contain or ventilate any construction or remodeling work
  • Keep any wood burning stoves or fireplaces clean and well ventilated
  • Regularly test carbon monoxide monitors
  • Track carbon dioxide levels in high traffic spaces and take active measures to prevent it from reaching high concentrations
  • Consider adding indoor plants for free, natural air filtering