Old mines still a blight on Tasmanian lakes

Tasmanian lakes are some of the most contaminated in the world, with new findings showing that the Tasmanian Wilderness World Heritage Area are heavily contaminated with dangerous metals.

A team of researchers from the Australian National University (ANU) found alarmingly high levels of lead, copper, arsenic and cadmium in all six lakes of the TWWHA region, with some exceeding the highest allowable levels in sediment guidelines for Australia.

Lead researcher Dr Larissa Schneider and Professor Simon Haberle said that the findings may present clear health concerns.

"This is a very severe contamination and it's very likely that the health of the local biota; bacteria, algae, fish and other organisms is being affected, but as this aspect hasn't been studied, we have no way of knowing," said Dr Schneider.

"As we know, concentrations of contaminants increase as they travel up the food chain so this has implications for anyone who consumes fish from these areas"

Dr Schneider said the Tasmanian contamination is on par with that in the Kurang River in Pakistan, contaminated by mining and the Shur River in Iran, subject to heavy metal pollution from non-mining activities such as waste dumping.

"I was very surprised by the high concentration results. When we compared the confirmed results with worldwide sites, we found that Tasmania's metal concentration levels were one of the highest ever reported," said Dr Schneider.

"We tested a number of metals and metalloids including selenium where a study in the US proved that lower concentrations than the ones found in Tasmania had affected the ability of fish to reproduce.

"It's even worse with Mercury and Lead which cause deformities in the offspring of affected fish. Some elements can also be carcinogenic so all this could be happening in Tasmania in an area we think is safe because of its world heritage listing," said Dr Schneider.

"In 1973, Tasmania did very well by being one of the first Australian states to legislate an Environmental Protection Act, but the government of the day exempted the mining companies from the rules so they continued to deposit waste into the rivers," she said.

The full article can be found here

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