We spend 90 per cent of our time indoors.  It's fair to say that the indoor air quality, or IAQ, of our homes is very important. Yet Health Canada has found that indoor air can be six to 10 times more polluted than outdoor air in some cities, and a poor IAQ can lead to a number of health problems, from headaches and shortness of breath to serious allergies and asthma. Common indoor air quality pollutants can be caused by dust, inadequate ventilation, chemicals, and high humidity levels that lead to mould or bacteria growth.