Air Quality FAQs

What does “indoor air” mean?


The National Health and Medical Research Council (NHMRC) defines indoor air as: “air within a building occupied for at least one hour by people of varying states of health.” So when we talk about “indoor air” we mean any building that houses people either an office, classroom, transport facility such as an airport, a shopping centre, hospital or child day care facility, or private home.


What defines “indoor air quality”?


Indoor air quality is defined as the totality of attributes of indoor air that affect a person's health and well being.


What is the cost of air quality testing?


It depends on the issue at hand. However, we can assure you that our service is one of the most cost-effective and affordable available in Australia. For a consultation please call us on 1800 878 262 or email


What causes indoor air pollution?


Indoor air pollution is caused by any source within the home or building that can release gases or particles.  This is made worse by inadequate ventilation when not enough fresh air comes in from the outside to dilute the emissions and move the pollution out of the building.


What are the sources of indoor air pollution?


There are many typically:


  • Heaters and gas stoves (of particular concern is poorly maintained or unflued gas heating),
  • Tobacco,
  • Formaldehyde and other chemicals from building materials and furniture,
  • Cleaning products
  • Air fresheners and other personal care items such as essential oils,
  • Central heating and air conditioning systems and of course
  • Pollution from the outside. 


Asbestos can often be present in older homes and special care must be taken with this dangerous material. Visit Asbestos Wise for more information


Ventilation - how does it work?


Ventilation allows fresh air from outside to come into a building and dilute the pollutants that may have accumulated. When there is inadequate ventilation levels of pollution may build up and impact on the health and comfort of residents and building users. Newer homes that are designed for maximum heating and cooling efficiency often have higher levels of pollution than older “leaky” homes.


How does outdoor air enter a house?


There are 3 ways for air to enter a house:


  1. Infiltration – air flows in from outside through various gaps in the building – around doors and windows, floors, ceilings and any other openings
  2. Natural ventilation – air flows in through open doors and windows. In both instances the air movement is caused by wind and the difference in temperature between outside air and the air inside.
  3. Mechanical ventilation – any device that moves air – these include heating ventilation and air conditioning systems (HVAC), fans that vent outdoors from bathrooms and kitchens.


What are the health effects of indoor air pollution?


There are the immediate effects including; irritation of the eyes, nose, and throat, headaches, dizziness, and fatigue. These are usually short-term and treatable, often by removing the person from the source e.g. leaving work.


Some disease symptoms, including asthma may appear soon after exposure to some indoor air pollutants.


There are a number of factors that impact on whether a person experiences an immediate reaction - age and the presence of medical conditions are the most important factors. The individual sensitivity of each person is very different.


Some symptoms are similar to the usual colds and virus’ we naturally experience, which can make it difficult to determine the cause. Close attention needs to be paid to when and where the symptoms occur. If there is a decrease in symptoms or severity when the person leaves the work place or home - an effort needs to be made to identify the source of the problem within the building.


What are the health effects of mould?


When water enters a building the occupants may notice odours and a range of health problems. The symptoms that may be experienced by people as a result of exposure to mould in the built environment are headaches, breathing difficulties, skin irritation, allergic reactions and asthma.  There are many thousands of different types (genera) of mould and all have the potential to cause health problems. Moulds produce allergens, irritants and in some cases toxins that may cause health reactions in humans.


More facts about mould…


  1. Potential health effects and symptoms associated with mould exposures include allergic reactions, asthma, and other respiratory complaints.
  2. Mould is impossible to eliminate from the indoor environment but it is important to understand to way to control indoor mould is to control moisture.
  3. If there is mould in your home, school or workplace it should be removed by cleaning. Any source of moisture should be eliminated to prevent mould from growing.
  4. Reducing indoor humidity (to 30-60%) helps to decrease mould growth. This can be achieved by:
    1. venting bathrooms, dryers, and other moisture-generating sources to the outside
    2. increasing ventilation; and
    3. using exhaust fans when cooking, dishwashing, and cleaning.
  5. Clean and dry any damp or wet building materials and furnishings within 24-48 hours of becoming damp to prevent mould growth.
  6. Clean mould off hard surfaces with water and detergent, and dry completely.
  7. Any absorbent materials affected by mould may need to be replaced e.g. ceiling tiles, carpets and other soft furnishings.
  8. Reduce condensation on cold surfaces such as windows, piping, exterior walls, roof, or floors by adding insulation.
  9. Avoid carpet in areas where moisture is always present e.g.  around sinks, or on concrete floors with leaks or frequent condensation.


Where can I find more information?


  • The Inside Story - A Guide to Indoor Air Quality  Office of Radiation and Indoor Air has been prepared by United States Environment Protection Agency and the United States Consumer Product Safety Commission. (An important resource and provides a comprehensive overview of the wide range of topics relevant to indoor air quality. (As the information provided in The Inside Story relates to the United States of America, there is some information not relevant to Australia e.g. regulatory agencies).


  • For more information about air quality visit the Environmental Protection Agency (US) website