2 February, 2012:
The effects of climate change could expose Australians to greater
risks from toxic contamination, a leading scientist has warned.
Increased flooding could release contaminants previously
regarded as secure into groundwater, rivers, oceans, the food
supply and atmosphere, the director of the CRC for Contamination
Assessment and Remediation of the Environment, Professor Ravi Naidu
said today.
“Most of our urban landfills contain highly toxic
substances from past decades – and were designed for the
climatic conditions at the time. These have now changed, with the
risk of bigger and more frequent floods, droughts, heat and acidity
releasing substances we thought were gone for good,” he
says.
Professor Naidu is inviting Federal and State governments and
Environment Protection Agencies to rethink nationwide contamination
and cleanup policy in the light of the risk that yesterday’s
poisons could be remobilised into our environment.
“The floods in Queensland and northern NSW illustrate how
things are changing – and how we can no longer count on toxic
disposal systems designed half a century or more ago to work as
well in future under changed climate conditions,” he
says.
“From now on all landfills and contaminated sites will
need better flood protection upstream and high-tech contamination
barriers downstream to filter the groundwater that leaches out of
them, and remove the heavy metals, pesticides, hydrocarbons and
organic toxins it contains.”
Other contaminated land containment systems such as cover
systems, stabilisation, etc could also be adversely impacted by
climate change via factors such as wet-dry and freeze-thaw
cycles.
Professor Naidu says that climate change also brings increased
urgency to the task of rehabilitating contaminated lands.
“Where you have a large area of contaminated land it is
often very hard for plants or soil microbes to regrow, leading to
reduced carbon sequestration which adds to climate change.
Researchers are currently working on specially-adapted trees,
grasses and soil microbes which can be used to recover these sites,
devastated by historic industrial and mining activities – but
there is a need to speed up national efforts to adopt such
solutions, he adds.
Another form of contamination likely to accelerate under climate
change is acidification.
“Acid rain produced by the industrial release of sulphur
dioxide from coal fired power stations into the atmosphere is
poisoning lakes, forests and soils in the northern hemisphere. When
soils become more acidic they can release toxic heavy metals as
well as carbon.
“At the same time the carbon dioxide we release when we
use vehicles or fossil-fuelled electricity is increasing acidity in
the world’s oceans and endangering their food chains,”
Prof. Naidu explains.
“There are engineering solutions to these problems, which
involve trapping the gases before they enter the atmosphere and
disposing of them safely – but they are costly and will need
to be adopted universally.”
These issues illustrate how climate change can affect the total
toxic load delivered to society in its food, water and environment,
and the importance of acting in a timely fashion to prevent this
happening.
“People often regard contamination as a local issue, and
contaminants as things which tend to stay in one place or where
they are put.
“This is no longer the case. Man-made contamination by
toxic organic chemicals and metals is already swirling around the
planet in air, water and wildlife – and there is a risk that
the changes unleashed by climate change will mobilise even
more,” Prof. Naidu warns.
“Containment of contaminants is critical in the
sustainable management of legacy contaminants. It is not yet time
to be alarmed – but we should be concerned. And we should
certainly begin to think about the solutions.”
Australian industries, including the mining , energy and
agriculture sectors, are world leaders in developing and
implementing environmentally-friendly and cost-effective solutions
to contamination issues, he says.
“If Australia makes an early start in overcoming these
unforseen impacts of climate change it will also position us as a
world leader and exporter of clean, green solutions for a changing
world. It will not only be healthy – it will also be
profitable and create jobs.”
More information:
Prof. Ravi Naidu, Managing Director, CRC CARE, 08 8302 5041 or 0407
720 257
Professor Nanthi Bolan, UniSA, 08 8302 6218 or 0447 182320
Julian Cribb, CRC CARE media, 0418 639 245
