Minatmata

One cannot talk about Mercury poisoning and pollution without discussing the Minamata disaster, which is considered one of the greatest tragedies of industrial pollution. Hylander and Goodsite's paper in 'Science of the Total Environment' journal, 'Environmental costs of Mercury Pollution', outlined very clearly the grave repercussions of the Minamata disaster.

In the early 1950's people began to report ecological changes in the area, seabirds had begun to fall out the sky, fish dying unexpectedly and, perhaps most famous, the cats began to 'dance'. A year after the emergence of 'dancing' cats the same symptoms appeared in humans who lived around the bay of Minamata, resulting in the name 'Minamata Disease'.

By 1959, it was established that the source of the disease was pollution from Chisso, a company that had previously established itself decades before in Minamata. Yet, despite confirmation and with the backing of the Japanese government, Chisso continued to emit Mercury (Hg) to the environment. In 1968 a special pond was set up for the waste but, as Highlander and Goodsite point out, this only contributed further via ground flows. The factory was shut down three years later, however, the same methods are still employed in the creation of vinyl chloride in China 'showing that short sighted economy still outweighs human and environmental health' (Hylander and Goodsite 2006:362).

Studies show that between 1932 and 1968 more than 225 tons of Mercury was emitted to the ocean, directly causing 100 deaths and indirectly causing the deaths of the tens of thousands diagnosed with brain damage. Between 1980 and 1990 there was a large scale effort to clean up Minamata. The bay was split in two by a large concrete wall and any sediment that contained 8.75 mg kg-1 of Mercury was placed on one side of the bay and buried under a layer of fabric and virgin soil. 10-30% of the Mercury emitted was distributed through out the ocean around the bay but despite this effort Hylander and Goodsite estimate that only 50% of the mercury has been dealt with.

Reference: Hylander and Goodsite (2008) 'Environment costs of Mercury,' Science of the Total Environment 368 (1) 352-370.