Water World Pollution

Minamata disease causes serious damage to the nervous system, resulting in uncontrollable shaking and muscle wasting. It also produces appalling deformities in the children of sufferers. A debilitating illness of the nervous system caused by mercury poisoning has re-emerged, scientists have warned. Minamata disease causes serious damage to the nervous system, resulting in uncontrollable shaking and muscle wasting. It also produces appalling deformities in the children of sufferers.

It is the first time it has been diagnosed outside the Japanese town from which it takes it name and where about 1,500 contracted symptoms in the 1950s. A toxic, organic form of mercury known as methyl mercury is believed to be responsible for the disease. The Japanese victims had eaten fish from a bay polluted by mercury from a metals plant. Methyl mercury attacks the cerebellum, which coordinates voluntary movements, and destroys the personality. Hiroshi Takahasi, an epidemiologist with the Japanese Ministry of Health and Welfare, said: "Survivors in Minamata are still suffering. It should not happen again." These included involuntary shaking, sensitivity to bright light, partial blindness and loss of muscle strength. Both research teams pinned the blame on the consumption of methyl mercury in fish. They agree that bacteria living in oxygen- starved conditions in river sediments are believed to convert inorganic mercury into the dangerous methylated form.

The neurological disorder caused by the poisoning, known as Minamata disease, is linked to eating fish polluted by mercury that a chemical firm dumped. The condition causes shivering limbs, seizures and problems with talking. About 20,000 people have applied to be recognised as sufferers and nearly 4,000 of them still seek compensation. About 1,000 people have gathered in the south Japanese town of Minamata on the 50th anniversary of a mercury poisoning outbreak that claimed 2,000 lives. The memorial service took place alongside the bay on the south-western island of Kyushu where the giant Chisso Corp dumped the mercury for a number of years. The problem was first officially recognised on 1 May, 1956 but the dumping continued until 1968 and the firm was not held responsible until 1973.

At the service, Minamata Mayor Katsuaki Miyamoto told sufferers and their relatives: "We know the problem once caused by the pollution has not been solved even after 50 years. "We need to lead the way for the human race and to continue to sound the alarm to prevent such a tragic event happening again." On Sunday a memorial was unveiled in Minamata to the victims. On Saturday, hundreds of people with the disease and their supporters marched in Tokyo to pressure the government into further expanding help to sufferers. Japanese Prime Minister Junichiro Koizumi last week expressed official regret for government failures. Although the government says it will expand its assistance programme, it is not planning to redefine symptoms to allow wider compensation payouts. Chisso's chairman, Shunichi Goto, was among those attending Monday's ceremony. One of the world's worst cases of mercury poisoning happened at Minimata Bay in Japan in 1952, also when effluent from a factory reached local waterways. Nearly 70 people died, and hundreds of others were affected. Most were poisoned by eating contaminated fish.