|UN to tackle mercury menace|
by MICHAEL RICHARDSON, The Canberra Times
March 3rd, 2009
Fear sparked by global recession, strains on banks and volatile paper currencies has brought the glitter back to gold. Its value has been rising rapidly in recent months, as investors seek a safe-haven from the economic and financial storm.
But gold's resurgence has strengthened demand for its ugly long-time associate, mercury, a toxic heavy metal widely used in Asia, Africa and Latin America by millions of small-scale gold miners.
The United Nations Environment Program estimates that about 6000 tonnes of mercury are released each year into the air, land, rivers, lakes and seas, creating a global pollution danger. The liquid metal damages the human nervous system, and impairs the functioning of the liver and thyroid glands. It also causes memory loss and disturbed vision.
Of the 6000 tonnes, about one-third comes from burning coal to generate electricity, power industries and heat homes. Increased coal use in Asia means that mercury emissions are rising in the region. Gold mining is the second biggest source of mercury releases.
When the poison is belched into the air from power plants, smelters and incinerators, it returns to earth via rain, with bacteria and other natural processes converting it to organic methylmercury in lakes, rivers and oceans.
Released into river systems that flow into the sea, the poison is widely dispersed through the world's oceans. Scientists say that as global warming melts the Arctic, mercury trapped in ice and sediments is being re-released back into the oceans where it builds up through the food chain as bigger creatures consume smaller ones.
To tackle the mercury scourge, more than 140 nations meeting at UNEP headquarters in Nairobi, agreed last month to negotiate a binding global treaty to tighten controls on its use. The accord, backed by China, India and many Asian countries, came after the Obama administration announced it had reversed the US stance on the issue and was now in favour of a ban on mercury. The European Union has called for the ban to start by 2011.
However, reaching agreement on the details of the treaty and then implementing it effectively will be difficult and take years. It will involve finding cost-effective substitutes for mercury in products like thermometers, high-intensity lamps and liquid crystal displays, and in processes such as paper-making and plastics production.
It will also involve tighter controls on mining, storage, export and import of mercury. Most mercury mines are now closed and China only supplies its own market. So mercury comes from the leftover stockpiles of shuttered mines or the dozens of companies in Europe and the US that recycle the metal from old light bulbs, batteries or industrial waste, according to the UN and the Zero Mercury Working Group, a coalition of 40 organisations that campaigns to reduce mercury use.
International trade in mercury, which is easy to transport, is poorly regulated. Mercury supplied for legal purposes is often diverted to gold mining, where it fetches a much higher price. In Indonesia, for example, use of mercury in gold mining is illegal. However, the price of gold has more than tripled since 2001 and mercury is the easiest way to separate gold from ore.
Tens of thousands of remote mining sites have mushroomed, mostly in Asia, Latin America and Africa as poor people try to make money from the gold boom. Small-scale gold mining uses as much as 1000 tonnes of mercury each year. UNEP estimates that 10 million miners and their families in countries such as Indonesia, India, Papua-New Guinea, Brazil and Zimbabwe may be suffering from mercury poisoning or exposure. It says that on Mindanao, the main island in the southern Philippines, 70 per cent of gold miners may have chronic mercury intoxication.
Transitioning to a low-mercury world is a laudable and essential goal. But it will take a high degree of international cooperation and government action to achieve.
While the terms of a new mercury treaty are negotiated, steps will be taken to raise awareness of the risks in using the poison in small-scale mining.
The UN has already spent $US7 million in six developing countries, including Indonesia, to educate miners and local suppliers about mercury.
However, the miners like the liquid metal because it is relatively cheap, works fast, and leaves the gold cleaner than traditional panning. The only readily available alternative is cyanide also a poison that can ravage human and health and the environment.
The writer is a visiting senior research fellow at the Institute of Southeast Asian Studies in Singapore.