September 13, 2011:
Fourteen kinds of heavy metals and toxic flame retardants have been
detected in contaminated water draining from landfill sites
in Australia, environmental researchers will report to the CleanUp
2011 conference in Adelaide today.
Steps should be taken to prevent further leaching, as traces of
these metals were also found in groundwater adjacent to the
landfills, Ms Peeranart Kiddee and Professor Ravi Naidu from CRC
CARE and The University of South Australia say.
“Most of these materials have probably leaked from electronic
waste, which includes old computers, mobile phones, refrigerators,
televisions, batteries, wires with flame-retardant casings and
more,” says Prof. Naidu.
“As e-waste only came into the picture 10 years or so ago, we
used to dispose of most of it in landfills. Approximately 84% of
e-waste was dumped, with only 10% being recycled in those days.
“Up until 2006 there was three times more e-waste going to
landfill, and no fewer than 234 million electronic waste items were
sent to landfill in 2009.”
Toxic metals measured by the researchers included arsenic, cadmium,
cobalt, chromium and zinc, Ms Kiddee says. Water leaching from
landfills also contained PBDEs (polybrominated diphenyl ethers),
flame-retardant chemicals found in many electronic products. PBDEs
belong to the class of persistent organic pollutants (POPs) and can
be highly toxic to both humans and the environment.
“The content of PBDEs found in Australian landfill leachates
is much higher than those from Japan,” Prof. Naidu says.
“One reason for this is that Japan incinerates its waste,
decreasing the toxicity, while Australia disposes of them to
“As many of our landfills are not actually designed to
accommodate e-waste, we run a high level of risk if contaminated
water escapes from them.
“When groundwater is contaminated it in turn
contaminates soil. Both water and soil can be used for growing
crops, with the result that the toxins may enter the food chain,
which is highly undesirable.”
The researchers are conducting an on-going study to establish the
extent and severity of contaminant leaching from the nation’s
“We suspect that e-waste discarded over the years is already
in a lot of our landfills. It will be very expensive and
impractical to excavate what’s already buried, due to the
large size of these dumping grounds,” says Prof. Naidu.
“What we can do now is find out how extensive the problem is,
and develop cost-effective ways to prevent the leaching. One way is
to put a cap on the sites, which can minimise the impact of
rainfall to them. Another is to erect underground barriers that
will absorb and immobilise the pollutants.
“Society’s rising demand for and dependency on electric
and electronic goods means the amount of e-waste will increase,
especially as these products tend to have shorter lifecycles and
are quickly replaced by new ones,” Prof. Naidu says.
“The answer is to develop manufacturing systems that minimise
contamination in the first place, and which close the loop by
efficiently recycling materials back into electronics production
Prof. Naidu and Ms Kiddee will deliver their presentation at 2 pm
on Tuesday September 13.
CleanUp 2011 incorporates the 6th International Workshop on
Chemical Bioavailability in the Terrestrial Environment (7–9
September 2011) and the 4th International Contaminated Site
Remediation Conference (11–15 September 2011). It is hosted
by the CRC for Contamination Assessment and Remediation of the
Environment (CRC CARE).
CleanUp 2011 is being held at the Hilton Adelaide hotel in
Adelaide, South Australia.
Prof. Ravi Naidu, Managing Director, CRC CARE, UniSA, 0407 720
Ms Peeranart Kiddee, CRC CARE, UniSA, 08 83026254 or 0423 341
Meredith Loxton, Acting Communications Manager, CRC CARE, 08 8302
3925 or 0429 779 228
Sharmin Patard, Communications Officer, CRC CARE, 0437 917 352