http://www.iol.co.za/index.php?set_id=1&click_id=&art_id=nw20100120203538542C133806
Mercury pollution a global problem
Concern about global mercury pollution has been mounting for decades and a recent expert report for the United Nations Environment Programme warned that mercury now appears to be present all over the world in concentrations that may affect people and wildlife.
That report said the highest average mercury levels were found in large predatory fish, such as shark, swordfish, barracuda and marlin, along with seals and some whales.
In Sweden, fish in more than 50 percent of inland lakes are polluted with mercury above World Health Organization limits, and women of childbearing age have been advised not to eat any of these fish, while the rest of the population is advised not to eat fish more than once a week.
In Finland, several lakes and parts of the coast were heavily polluted with mercury by the paper/pulp factories and other industries in the 1960s and 1970s, but levels of mercury are still high in many Finnish lakes despite efforts to reduce the pollution.
Although high mercury levels are more common around industrial areas or coal-fired power stations, high levels of mercury have been found in remote parts of Greenland and the Arctic, where many people live on fish and marine mammals.
The most serious cases of poisoning were in the Japanese town of Minamata in the late 1960s because of mercury pollution from a local chemical plant. Several new-born babies were crippled by cerebral palsy, blindness and severe mental retardation - even though their mothers showed no evidence of harm.
This is one of the reasons why health authorities advise pregnant mothers and women of child-bearing age to limit their exposure to mercury in fish.
Over the past four years, local researchers have been trying to gather more data on mercury pollution in the environment in a project known as the SA Mercury Assessment Programme. The full results have not yet been released.
Mercury is also a by-product of coal, and there are concerns that South Africa's dependence on coal-fired power stations has led to extensive pollution over the past few decades as tiny particles of mercury from Eskom stations drift in the air over long distances before dropping down to earth to poison the soil, water and sea.
Mercury is also used widely in common products like fluorescent light bulbs, batteries, car headlamps, measuring instruments and dental amalgams.
Toxic? High levels of poisonous chemicals have been found in fish caught off South Africa's coast.
