Cleaning up a deadly lifesaver
Australian scientists are pioneering a way to clean up one of the world’s most toxic and widely-used environmental pollutants – fire fighting foam.
Researchers at the CRC for Contamination Assessment and Remediation of the Environment (CARE) and University of South Australia have developed techniques for the assessment and remediation of highly-persistent chemicals used for decades worldwide as fire retardants.
A team led by UniSA’s Associate Professor Megharaj Mallavarapu has developed a field test kit and two methods of cleaning up the fluorine compounds which form the basis of fire retardants commonly used by military and civilian authorities round the world.
"These fluorinated compounds – known as PFOS – are highly persistent, both in humans and in the environment, more so even than DDT. They last for years and may have serious health and ecological consequences," Prof Mallavarapu said.
"We have established they are toxic to various soil organisms, including worms and, once in water, there is a risk they may enter the food chain. It is suspected that they may be linked to cancer."
The team’s field test kit for establishing the level of PFOS contam-ination is a low-cost alternative to expensive and time-consuming laboratory testing.
Prof Mallavarapu said that Australia’s development of a test kit and clean-up methods have the potential for commercial sale around the world, as environmental agencies come to grips with the extent of pollution from the deadly – yet lifesaving – foams.
"Although the fire-fighting foams which use PFOS are being gradually phased out, they are still in widespread use – and sites where they have been used or spilled remain contaminated for many years," Prof Mallavarapu said.
But tests have shown that new fire-retardant chemicals are also persistent in the environment and toxic to various forms of life.
"We have also been first to find a way to devise a test and clean up method for the new compounds – although the makers will not tell us what is in them because it is still under patent," Prof Mallavarapu said. "We had to work out the constituents for ourselves in order to devise a clean-up strategy."