The Minamata disaster - 50 years on
Also in this week's column:
- Is there any evolutionary advantage in snoring? 
- What is deep vein thrombosis? 
- Can leaving a baby to 'cry it out' cause brain damage? 
The Minamata disaster - 50 years on
It is now 50 years since the most horrific mercury poisoning disaster the world has ever seen took place in Minamata, Japan.
In May 1956, four patients from the city of Minamata on the west coast of the southern Japanese island of Kyushu were admitted to hospital with the same severe and baffling symptoms. They suffered from very high fever, convulsions, psychosis, loss of consciousness, coma, and finally death.
Soon afterwards, 13 other patients from fishing villages near Minamata suffered the same symptoms and also died. As time went on, more and more people became sick and many died. Doctors were puzzled by the strange symptoms and terribly alarmed. It was finally determined that the cause was mercury poisoning.
Mercury was in the waste product dumped into Minamata Bay on a massive scale by a chemical plant. The mercury contaminated fish living in Minamata Bay. People ate the fish, were themselves contaminated, and became ill. Local bird life as well as domesticate animals also perished. In all, 900 people died and 2,265 people were certified as having directly suffered from mercury poisoning - now known as Minamata disease.
Beyond this, victims who recovered were often socially ostracised, as were members of their families. It was wrongly believed by many people in the community that the illness was contagious.
The chemical plant was suspected of being the culprit in the environmental disaster almost from the beginning of the illness outbreak, yet speaking out against the chemical plant was forbidden. The plant was a major employer and enjoyed considerable economic and political clout all the way to the national government.
Defenders of the chemical plant argued that it must be innocent since the plant had been in operation since 1907 without previous problems. It manufactured fertilizer.
A riot by local fisherman in 1959 finally moved the government to investigate the cause of the illnesses and deaths. Even so, it took officials 12 years from the first deaths to finally admit the cause of the contamination and order a halt to the mercury dumping into Minamata Bay.
Yet the Minamata disaster story is still not over. In 2006, in the Seishin Shinkeigaku Zasshi, Dr K Eto from the Japanese Ministry of the Environment and the National Institute for Minamata Disease, writes that: "Over the years, new facts have gradually surfaced, especially after 1995, with the resolution of the political problems surrounding Minamata disease".
For example, the mystery as to why the first 50 years of plant operation brought forth no disaster has been recently solved. It has been revealed that the plant modified its operations in August 1951 and started dumping large amounts of mercury directly into Minamata Bay only from that time.
The health of survivors and their children are being monitored. A permanent museum and annual community ceremonies commemorate the worst mercury poisoning environmental disaster ever. Today, 50 years on, the lessons of Minamata remain.
- During his relatively long lifetime, Sir Isaac Newton (1642-1727), perhaps the greatest scientist that ever lived, suffered two serious bouts of uncharacteristically erratic behavior. Some historians believe he suffered from a mild form of mercury poisoning. They point out that Newton was conducting experiments with mercury at the time of both occurrences.
- Mercury was used in the haberdashery industry into the 20th century. Hat makers were known to often suffer mental illnesses although the source of such illnesses was unknown. This is the basis of the name of the "Mad Hatter" character in Lewis Carroll's Alice in Wonderland.
Stephen Juan, Ph.D. is an anthropologist at the University of Sydney. Email your Odd Body questions to email@example.com