Australians consistently rank air pollution as a major environmental
             concern. The state of our air is an important factor in the quality of life of
             Australian cities. It affects the health of the community and directly
             influences the sustainability of our lifestyles and production methods.
             It is generally recognised that Australians spend 90% or more of
             their time indoors. Despite this, little research has been done on the quality
             of air in our homes, schools, recreational buildings, restaurants, public
             buildings, offices, or inside cars. Poor indoor air quality can result in
             significant adverse impacts on our health and environment. These impacts
             carry a significant cost to the economy. The CSIRO estimates that the cost
             of poor indoor air quality in Australia may be as high as $12 billion per year.
             In recent years, relative risk studies performed by the US EPA and its
             Science Advisory Board have consistently ranked indoor air pollution among
             the top five environmental risks to public health.
             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. This can include the office, classroom, transport
             facility, shopping center, hospital and home. Indoor air quality can be
             defined as the whole of attributes of indoor air that affect a person's
             health and well being. A major concern with respect to indoor air quality is
             the use of gas cookers and unflued gas heaters. These two sources can
             often contribute a large percentage of the pollutants found in domestic
             buildings. Increasingly, as buildings have become better sealed from the
             external environment, pollutants being released from indoor sources are
             being found at higher concentrations. As a result of studies implicating
             unflued gas heaters in indoor air quality issues, unflued gas heaters are
             being...