Occupants of new Australian homes may be exposed to up to 20 times the maximum allowable limits of indoor air toxics an Australian first study has found.

The CSIRO study shows that the National Health & Medical Research Council's (NHMRC) maximum limits of total volatile organic air toxics may be exceeded in such houses for at least ten weeks after completion.

Steve Brown of CSIRO Thermal & Fluids Engineering says, "This means that up to 500,000 Australians moving into around 120,000 new homes every year could be subjected to high levels of airborne toxics for months."

"Air toxics were at their highest at construction showing many materials used in building homes are significant sources of indoor air pollution. The most potent sources are paints, adhesives and some wood-based panels."

Further CSIRO measurements in 27 suburban Melbourne residences more than a year after construction identified 27 airborne toxics. These included the carcinogens benzene, formaldehyde and styrene, and a cocktail of methanol, ethanol, acetone, toluene, dichlorobenzene plus a number of less well-known toxics.

Mr Brown says, "In these established homes, indoor air still carried four times the total volatile organic toxics found in outside air, although the level in all but two of the homes was within the NHMRC guideline of 500 micrograms per cubic metre".

"This guideline was exceeded in all the new buildings studied."

Toxics found in the new and renovated buildings included:

• Styrene; a recognised carcinogen was detected in two homes
• Odour producing toxics, 4-phenylcyclohexene and nonaldehyde; were readily smelt in two of the homes (in one case for years)
• Formaldehyde; irritation levels were found in one of the new homes.

The carcinogen benzene was not present in higher amounts in the new and renovated buildings than in the established dwellings, although its presence was highest in homes with attached garages and in a few other homes where the cause could not be identified.

Of further concern were the formaldehyde levels. The measurements indicate that long-term indoor air pollution is likely from new building materials emitting formaldehyde such as manufactured wood-based panels used principally in flooring, furniture and cabinets.

Formaldehyde is considered a Category 2A carcinogen (probable cancer causing chemical) by the International Agency for Research on Cancer.

"Identifying these air toxics is part of a worldwide focus on identifying and controlling the cost to human health associated with modern living," says Mr Brown.

"These measurements are the first of their kind conducted in Australia and are in agreement with findings of similar studies conducted overseas. Together with CSIRO's complementary studies into pollutant emissions from materials and appliances, they allow us to link people's exposures to these pollutants with how we build and furnish our built environments," he says.

This study of indoor air toxics was funded by CSIRO for the benefit of all Australians to assist in developing preventive health strategies for the community.

CSIRO estimates that indoor air pollution costs the Australian community in excess of $10 billion a year in illness and lost productivity.

There's now an urgent need to move from this assessment phase to implementing control strategies through relevant Government agencies and industry organisations.

More Information:

Steve Brown, Principal Research Scientist, CSIRO Thermal & Fluids Engineering, Ph: 61 3 9252 6027

Email: Steve.Brown@dbce.csiro.au  

Ken Anderson, Manager Communication, Ph: 61 3 9252 6172 Mob: 0414 457 214

Occupants of new Australian homes may be exposed to up to 20 times the maximum allowable limits of indoor air toxics.