Tuesday, August 29, 2006

"Wand" will highlight environmental risks

Australian scientists are developing a “magic wand” to find out how dangerous is the contamination lurking in the soils and groundwater beneath our cities.

Researchers in the CRC CARE (the Cooperative Research Centre for Contamination Assessment and Remediation of the Environment) are developing special sensors to analyse the toxic stew of chemicals under old industrial sites – so they can be safely treated and the land made safe for future use.

“We're developing sensors that will give us a much better idea of the pollution present over time,” Associate Professor Jack Ng of CRC CARE and The University of Queensland said.

“These sensors reveal the concentration of the contaminants and their potential effect on humans, plants and animals. They will enable us to search for specific contaminants that are of concern or to diagnose mixtures of pollutants.”

In some cases, the “sensors” will consist of special microbes tuned to light up if they encounter particular contaminants, or show toxic stress by changing shape, altering their coats or even dying.

“We've already developed bugs that light up when they come in contact with a certain contaminant. You can do it by inserting a lux (light-generating) gene into the microbe or by using a fluorescent probe,” Dr Ng said.

One of the approaches the team is developing is to put the sensors on a rod – referred to as a “magic wand” – which can be stuck in the soil or water and provide an on-the-spot readout on the presence of toxic contaminants. This will dramatically reduce the time needed to send samples to a laboratory for analysis.

The managing director of CRC CARE, Professor Ravi Naidu, said risk assessment was the critical first step in making society safe from the contamination caused by past decades of industrial development.

“In order to treat these sites effectively and economically, we need to know exactly what's down there,” he said.

“The tools being developed by CRC CARE's Risk Assessment Programme will help us to do just that.”

Dr Ng said the new sensors would be quick, low cost and easy to use. In many cases they would provide an answer in the field – a huge help to site developers who suddenly discover they had a contamination problem to deal with.

His team is also working on a way to predict the impact on the Australian population of exposure to particular toxic substances.

“We are seeking to establish what is 'normal' in people in terms of their response to particular substances, so that we can say with confidence whether or not they are being poisoned by exposure to something that may be in the environment, whether it is natural or man-made," he said.

“We believe this will be a significant reassurance to many people who worry about whether their health is being affected by exposure to contamination, by providing a confident answer whether or not that substance may be to blame.”

Another project is investigating how oil spills move underground in water, and how they can re-enter the atmosphere as potentially toxic vapours. This will help Australia to refine its health and environmental impact standards, Dr Ng said.

“Knowing what you're dealing with and whether or not it poses a risk to living creatures and people is half the battle when dealing with contamination,” he said.

“Sometimes it will simply tell you that you don't have a problem. At others it will give you a much clearer idea of how to fix it.”

The CRC CARE technology could potentially add billions of dollars to the Australian economy by helping to transform “problem” contaminated sites in inner-city locations into real estate safe for residential or business development, Professor Naidu said.

“It will help put Australia in the world lead in dealing with a problem which every society on earth is facing. There are an estimated three million contaminated sites in Asia alone, and we're getting calls all the time asking us to help clean them up,” he said.

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