Mercury

Papermill Mercury Discharges Accumulate in the Gippsland Lakes

The Australian Paper Manufacturers (APM) Ltd’s paper pulp mill at Maryvale in the Latrobe Valley has discharged mercury-contaminated wastes into the valley airshed, the Latrobe River, and the Latrobe Valley sewerage system for many years. APM’s chlor-alkali plant, which manufactures chlorine and caustic soda for use in the paper manufacturing process, uses mercury electrodes in the electrolytic process which produces these chemicals. Electrolysis converts the mercury into an inorganic state, and it is later discharged as a waste product. Inorganic mercury is not highly toxic, but when discharged to water it is gradually converted into methyl mercury, which accumulates in plants, animals and humans, and in high concentrations is extremely toxic.

APM’s mercury discharge was one of the most pressing problems facing the EPA upon its creation: the discharge had continued virtually unchecked for almost 40 years, the pollutant involved was highly dangerous, the ecosystem needing protection was an important one, and the company involved could marshal unrivalled economic and political muscle. What ensured bordered on a conspiracy to effect harm to the public interest for reasons of private gain: APM leant on the government and the EPA, and consequently the company was virtually able to write its own licence to pollute.

Read the whole story at: Australian Paper – Mercury History Lesson

Mercury poisoning affects fish, dolphins

Gippsland Times
Jessica Bennett
16 June 2008
MERCURY poisoning appears to be the cause of nine dolphin deaths in the Gippsland Lakes over a 12 month period. Water quality monitoring during the past ten years shows that the waters from Lake Wellington have consistently higher mercury concentrations than those found in other parts of the Gippsland Lakes. This has led to a 58 per cent increase in mercury levels in black bream (fish) compared with 20 years ago. Research from the School of Biological Sciences at Monash University identified the sources of mercury in the Gippsland Lakes catchment as having anthropogenic (originating from humans) rather than natural origins.According to the research, mercury was widely used for the recovery of gold and it is estimated that between 1850 and the 1930s around 63-76 tonnes of mercury was released into the Gippsland Lakes.Researchers said the dolphins absorbed the mercury from eating the black bream. Mercury has been shown in previous national studies to bioaccumulate in dolphins, but this is the first study to find particularly high levels in stranded animals in coastal Victoria.Bioaccumulation is the food chain process whereby smaller fish containing mercury are eaten by larger mercury contaminated fish, which are then consumed by dolphins, who can consume up to ten kilograms of fish a day.Supervisory researcher Dr Ross Thompson said the mercury concentrations averaged 3.45 milligrams of mercury per kilogram of tissue compared to 1.32 mg per kg in living dolphins.

“Mercury levels detected are sufficient to cause significant health impacts and were comparable to those found in areas of the world that are considered highly polluted, including the Mediterranean Sea,” Dr Thompson said.

According to the research, recent episodes of elevated mercury concentrations have been reported in the waters of the Latrobe, Avon, Mitchell and Tambo Rivers.

Eventually these contaminated sediments will be deposited within the lakes system.

Some might escape into Bass Strait, but most would be trapped in the Gippsland Lakes.

“Dolphins may be becoming stranded as a direct consequence of mercury contamination which damages their neurological system,” he said.

Dr Thompson said it was critical that further studies were done to ensure any further decline in dolphin health could be identified and managed.