Indoor Air Quality

Low indoor air quality is a growing problem, especially during the winter months. Learn about the causes and effects of this typical Canadian problem.

Poor Indoor Air Quality

Feeling tired all the time? often sick? breathing related problems?  There is a good chance low indoor air quality is causing these issues.

Poor indoor air quality is registered in a large percentage of Canadian homes every year. Houses in northern latitudes tend to insulate off the outside air during the winter months, causing pollutants and irritants to trap and recycle in the house, sometimes for years!

What Causes Indoor Air Problems?

Indoor pollution sources that release gases or particles into the air are the primary cause of indoor air quality problems in homes. Inadequate ventilation can increase indoor pollutant levels by not bringing in enough outdoor air to dilute emissions from indoor sources and by not carrying indoor air pollutants out of the home.

This problem becomes even worse if the air filters in the house are substandard in quality or have needed replacement. 

Clogged Vents

Amount of Ventilation

When too little outdoor air enters a home, pollutants can accumulate to levels that can pose a threat to your health and comfort. Unless they are built with special mechanical means of ventilation, homes that are designed and constructed to minimize the amount of outdoor air that can “leak” into and out of the home may have higher pollutant levels than average homes. This is true of most houses built in an around Calgary.

However, because some weather conditions can drastically reduce the amount of outdoor air that enters a home, pollutants can build up even in homes that are normally considered “leaky” or have acceptable levels of ventilation.

Poor Indoor Air Quality can cause a variety of health problems:


Health issues consequent of low indoor air pollutants may be experienced soon after exposure or, possibly, years later. Here is a list of what to expect.

Poor Air Quality

Signs and symptoms caused by poor indoor air quality can mimic many diseases and health conditions:

  • Recurring sickness ( constantly getting sick )
  • Constant coughing
  • Stuffy nose
  • Headaches
  • Difficulty breathing
  • Problems concentrating ( “hazy feeling” )
  • Flu and cold like symptoms
  • Other

Your home can also experience some signs:

  • Your home gets dusty fairly quickly
  • Higher than usual energy bills ( due to blocked or partially blocked vents)

Immediate effects may show up after a single exposure or repeated exposures. These include:

  • irritation of the eyes, nose, and throat
  • headaches
  • dizziness
  • fatigue.

Such immediate effects are usually short-term and treatable. Symptoms of some diseases, including asthma, hypersensitivity pneumonia, and humidifier fever, may also show up soon after exposure to some indoor air pollutants.

children, elderly people,  and at-risk individuals usually experience these problems first.

Certain immediate effects are similar to those from colds or other viral diseases, so it is often difficult to determine if the symptoms are a result of exposure to indoor air pollution. For this reason, it is important to pay attention to the time and place symptoms occur. If the symptoms fade or go away when a person is away from home, for example, an effort should be made to identify indoor air sources that may be possible causes. Some effects may be made worse by an inadequate supply of outdoor air or from the heating, cooling, or humidity conditions prevalent in the home.

Even the most meticulous looking home can hide these dirty ducts behind it. Dirty air ducts are often the source of the problem
Other health effects may show up years after exposure has occurred or only after long or repeated periods of exposure. These can be severely debilitating or fatal.
Some of the long-term effects of poor home ventilation are:
  • Chronic respiratory diseases
  • Heart disease
  • Some Cancers (Lung Cancer)
  • Chronic fatigue
  • Other

While pollutants commonly found in indoor air are responsible for many harmful effects, there is considerable uncertainty about what concentrations or periods of exposure are necessary to produce specific health problems. People also react very differently to exposure to indoor air pollutants. Further research is needed to better understand which health effects occur after exposure to the average pollutant concentrations found in homes and which occurs from the higher concentrations that occur for short periods of time.

However, one conclusive fact is that the lower the indoor air quality of your home is the higher the likelihood to experience the above mentioned ‘effects’ on your health.

It is therefore prudent to try to improve the indoor air quality in your home even if symptoms are not noticeable.

Improving Indoor Air
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