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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 and University of South Australia have developed world-first techniques for assessing and remediating the highly-persistent chemicals used for decades worldwide as fire retardants.
A team led by 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,” Megha says.
“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.
“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.
“The same substances have also been widely used in the furnishing and textile industries as coatings for hard-wearing fabrics and carpets.”
The CRC CARE team is perfecting two techniques to clean up surface or groundwater contaminated with PFOS.
The team has also developed the world’s first low-cost field test kit for establishing the level of contamination of sites where PFOS compounds have long been in use. Normally, testing has to be done in the lab and is both time-consuming and expensive.
The PFOS foams are now being phased out and replaced with new fire-retardant chemicals whose composition is still a commercial secret. However tests by the team have shown the new 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,” he says. “We had to work out the constituents for ourselves in order to devise a clean-up strategy.”
Prof. Mallavarapu says that Australia’s development of a test kit and clean-up methods has potential for commercial sale around the world, as environmental agencies come to grips with the extent of pollution from the deadly – yet lifesaving – foams.
Editor's Note: Original news release can be found here.
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