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Health, psychology & science stories


Scary quality of our indoor air

20 August 2002

Published in The Age

In 1999 the CSIRO’s Dr Stephen Brown estimated that the air quality inside Australia’s buildings - that’s your home and mine, as well as our workplaces and classrooms - was so pathologically bad that it was adding up to $11 billion per annum to the nation’s health bill. The $11 billion included sick leave, medical expenses, insurance costs, and building audits and remediation.

No-one took much notice.

To put Dr Brown’s estimate in some perspective: HIH is thought to have lost around $4 billion when it collapsed, and the Victorian Government’s entire 2002 tax revenues are less than $9 billion.

Seven years earlier, in 1992, there had been similarly little outcry when the Royal Australian Institute of Architects, having surveyed Melbourne buildings, found that one in four people suffered from “Sick Building Syndrome” (SBS). Effects included “infections, allergies, irritations, toxic effects and psychological problems”.

The World Health Organization says that “most indoor air pollutants directly affect the respiratory and cardiovascular systems”. Frequently, contagious respiratory infections result from outdoor micro-organisms which have bred up in the indoor environment.

Adding its own concerns, Australia’s National Environment Protection Council (NEPC) said recently: “There is evidence that cancer, birth defects, genetic damage, immunodeficiency, respiratory and nervous system disorders can be linked to exposure to occupational levels of ‘air toxics’.”

As for specific causes, a 2001 NSW Public Works Committee report names “poor design of heating, cooling and ventilation systems” as well as “artificial lighting and ‘air’”. It concludes that 40-60% of offices may cause SBS.

But the elementary reasons for poor indoor air quality (IAQ) may be best-expressed in a 1999 report from the World Health Organization. The report blames “modern building design which has favoured tighter structures with lower rates of ventilation” and “products and materials that emit...chemical and biological pollutants”.

Dr Brown, the man who made the startling $11 billion estimate, is Principal Research Scientist in the CSIRO’s Air Quality Control Science section. He says that pollutants which arise from within buildings include “combustion gases from unflued gas heaters, especially nitrogen dioxide...carbon monoxide from faulty heaters...formaldehyde from wood-based panels such as particleboard, MDF and plywood, especially in mobile homes, offices, classrooms and caravans...car exhausts in inner city buildings, or in any building with attached garage, or in cars travelling in heavy slow moving traffic...lead from old paints, and environmental tobacco smoke”.

As for solutions, the experts interviewed by The Age believe they begin with the better design and regulation of buildings, and their interiors. “We need a government agency to take the lead on regulatory control,” agrees the CSIRO’s Dr Brown.

But no-one seems to be putting their hand up.

Setting standards for indoor air, says NEPC spokesman Piero Fioretti, is not within the NEPC’s ambit.

“Environemt Australia is not involved in regulation of indoor air quality for the workplace,” says departmental spoksewoman Deborah Nesbitt. “And indoor air quality is not regulated in other indoor environments such as homes.”

Jo Immig - an indoor air quality (IAQ) consultant, and advisor to a NSW parliamentarian - says, “No one department or agency is regulating indoor air quality at present. I think it’s because they don’t understand it’s an issue yet.” Dr Brown agrees that it’s “fallen between the cracks”.

There have, Immig says, only been ad hoc advances - such as an attempt (botched, unfortunately) to fix gas flues which were poisoning Victorian schoolchildren with carbon monoxide.

These are some ratios between a pollutant in Australia's indoor air and the same pollutant in our outdoor air:

(For example 8:1 would mean that there is 8 times the level in indoor air as outdoor air.)

* VOCs (‘volatile organic compounds’) in established buildings 8:1
* VOCs in new buildings >200:1
* Formaldehyde in conventional buildings 10:1
* Formaldehyde in mobile buildings 50:1
* Nitrogen dioxide in house with unflued gas heating ~5:1
* Respirable particles in buildings without smoking 0.1–1:1 (i.e. outdoor particles predominate)
* Respirable particles in buildings with smoking >10:1 (i.e. indoor particles predominate)

[From Controlling Indoor Air Pollution by Product Labels for Emissions from Building Materials and Contents, by SK Brown, CSIRO Division of Manufacturing and Infrastructure Technology.]

These ratios are alarming because we already we knew we had an outdoor pollution problem - and this tells us many of its elements are much worse indoors.

We spend 90 percent of our time indoors, 7 percent in cars, and only 3 percent outdoors. This obviously magnifies the indoor problem considerably.

Dr Brown believes the antidote to indoor air pollution should include increased building ventilation, air-cleaning devices, and reducing emissions from source materials.

However increased ventilation is problematic because the rates needed to achieve a desirable outcome would be “impractical” - and would also send heating and cooling costs soaring.

Air cleaning devices are “feasible”, however their performance and design remain problematic at this stage. Dr Brown is skeptical about negative ion generators - though a study last year in the Journal of Food Protection found that “high levels of negative air ions can have a significant impact on the airborne microbial load, and that most of this effect is through direct killing of the organisms. This technology...also causes significant reduction in airborne dust.” Jo Immig says ionisers are useful if they include filtration.

Finally, there’s the better management of pollution’s source materials - the optimal solution, believes Dr Brown. Presently emissions of indoor “toxics” are largely regulated at state level. But - as Jo Immig reiterates - numerous departments have responsibility for different aspects, and there’s no coherent approach, and little enforcement.

It’s Dr Brown’s opinion that a product labelling scheme would be an excellent start. He points to Denmark’s and Norway’s voluntary Indoor Climate Labelling scheme, which has developed standard methods of rating toxicity of indoor materials such as paints, carpets, partitions, wall systems, flooring, furniture and cabinets - based on their chemical emissions and their “odour/irritancy” potential.

But the bottom line is building design, says Jo Immig. “There’s no excuse with new structures now - there’s enough knowledge, and enough alternative materials which significantly reduce volatile chemicals.” She believes regulation should involve the building codes, health departments and environmental agencies.

“Practically speaking,” Immig says, “the people who could make the most difference are public works departments, and architects and builders. Indoor air quality is something that should be taught to designers at university.”

Environment Australia believes it is doing its bit, with a report consolidating all existing knowledge on indoor air quality, and a consumers’ brochure with advice for consumers on IAQ. Environment Australia has carried out studies on levels of indoor pollution, and helped trial a “low allergy school”.

But for all these great ideas, Jo Immig believes there won’t be a co-ordinated initiative “literally till dead bodies start piling up”.

In the meantime, what can ordinary people do to prevent indoor air pollution?

“The simplest answer I can give is to avoid using products, in any indoor setting, that emit unacceptable levels of pollutants,” says Dr Brown.

In Victoria, regulatory controls on industry, backyard burning and vehicle emissions have recently seen outdoor levels of “air toxics” such as benzene and toluene fall to 1993 levels. This suggests that we could yet find the will to staunch this multi-billion dollar wound to our national productivity and individual health.

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