It is the first outbreak outside Japan of Minimata disease, named after the Japanese town where it was first diagnosed in the 1950s. The illness, which results from contamination of a toxic form of mercury called methyl mercury, attacks the immune system and causes deformities in children.
Victims suffer from uncontrollable shaking and muscle wasting.
Harada examined 50 people from villages around San Luis do Tapajos. All had high levels of methyl mercury in their bodies and three had symptoms of Minimata disease. He suspects many more cases have not yet been diagnosed. It should not happen again. The experts said the Amazon villagers consumed the methyl mercury in fish, just as the Japanese sufferers had eaten fish from a bay polluted with mercury from a metals plant.