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University

Consumers should not be drinking water from local wastewater treatment plants, according to La Trobe environmental chemist, Dr Michael Angove until compounds known as EDCs – endocrine disrupting chemicals – are removed.

Unless special methods are used by authorities to remove these potentially harmful chemicals, they pass through wastewater treatment plants. Currently there are no EPA regulations on their removal nor standard tests for their detection.

Dr Michael Angove and his colleagues at the Colloidal and Environmental Chemistry Research Group at La Trobe's Bendigo campus are building up a body of knowledge about the detection and removal of these compounds.

'One of the big issues in water recycling quality and treatment is the range of pharmaceutical compounds and drugs in the water supply,' Dr Angove says.

Over the past ten years there has been an international furore over EDCs which mimic female sex hormones and are believed to be changing gender ratios in populations of fish and frogs.

In Europe they have been blamed for the early onset of puberty in females and the lowering of sperm counts in males.

'Very little is known about the presence of these chemicals in Australia,' says Dr Angove. 'They can be difficult to detect.'

The chemicals are found in high concentrations around centres of population. They are passed into waterways from a range of sources in households – the contraceptive pill, detergents, skin care products, perfumes – and from chemicals used in the plastics industry.

One EDC is known as triclosan. It is present in toothpaste and anti-bacterial handwashes.

Improving methods of detection

'There would be huge concentrations of triclosan at the wastewater treatment plant in Carrum,' Dr Angove says.

Dr Angove is working on improving methods of detection.

'In the past assays have used gas chromatography. You need to make the compounds more volatile so you can detect them. This has resulted in some compounds being overestimated and others underestimated.'

The researchers have devised new conditions for derivatising these compounds to minimise error. The results have been published internationally so that the knowledge can be shared with the international community.

Dr Angove's contribution to the study of the problem revolves around the environmental fate of these compounds once they enter the waterways.

'We want to know how much is in the environment. How long will they stay there and what is their fate? Do they roam around freely or do they congregate in sediments?'

His conclusion is that EDCs have a long life in sediments. Several methods have been investigated in their removal, including reverse osmosis, degradationtype processes and filtration systems.