Clare Loughlin
Mercury
has contaminated the Bay since 1932, the year when the Chisso factory began
dumping heavy metals into the Minamata Bay. The factory is a vital part of the
Minamata economy. When Chisso prospered,
the city of Minamata prospered. In
total, the corporation had been responsible for a quarter of all jobs in Minamata,
and over half of the cities tax revenue.
The Chisso factory manufactures plastics and nitrogenous fertilizers and
consequently produces various chemicals including acetaldehyde, acetylene,
acetic acid, vinyl chloride, and octanol. The production of these chemicals
created a great deal of toxic waste that the factory discharged into the Minamata
Bay from 1932 to 1968 creating point source pollution. Included in the toxic waste was methyl mercury
that began to bio accumulate in the fish and sea life living in the Bay due to
mercury’s fat soluble property.
In 1954 the Minamata
City Sanitation Office began receiving reports of unknown epilepsy like
symptoms, decades after the factory first began dumping industrial waste in the
Bay (1932). It’s likely that residents had been
contaminated for some time before 1954, due to mercury poisonings delayed
symptoms. Residents experiencing
symptoms were initially isolated, however doctors quickly realized the patients
were suffering from a neurological condition and that the disease was not
contagious. A huge
population of people were reportedly stumbling while walking, unable to write,
button their own buttons, hear, or swallow, and were trembling uncontrollably. The patients all experienced initial symptoms
of uncoordinated movement, numbness of lips and extremities, muscle weakness,
damage to hearing and speech, and constricted vision. Some more extreme cases experienced severe
symptoms within weeks of initial symptoms, experiencing insanity, paralysis,
coma, and death. The people of Minamata
referred to this illness as the ‘strange disease’.
Researchers also
found that children exposed to mercury during development were greatly affected. Between 1955 and 1958 30% of children born in
the most heavily contaminated areas were found to be mentally retarded having
what is now called ‘Congenital Minamata disease’. Also an unusually high number of children
were found to have cerebral palsy. Normally,
between .2 and 2.3% of children were found to have it, but 9% of children were
found to have cerebral palsy at the time people were experiencing strange
symptoms (Minamata Disease).
Around the same time people began
experiencing bizarre symptoms, cats also began exhibiting weird symptoms. Cat’s reportedly drooled, experienced
convulsions, and sometimes-even fell into the sea and drowned. The prevalence of sick cats gave the symptoms another name: 'cat’s dancing disease'.
Several other
animals experienced strange symptoms as well, fish were reportedly spinning out
of control and floating belly up, and birds fell from the sky. Irregular cat,
dog, pig, bird, fish, and human deaths continued for over thirty years.
By 1958 there were virtually no cats in
Minamata, Japan. However, the decimating
cat population in particular actually really helped doctors pin down the cause.
In 1957 researchers brought healthy cats
to Minamata and fed them locally caught fish. Within thirty to sixty days of the cat’s
arrival the once healthy cats developed the same symptoms as previously seen in
the cats from Minamata. The researchers performed autopsies on the sick
cats that revealed extremely high levels of mercury in cats, brains, livers,
kidneys, and hair. In 1957, the research group concluded the cause of the patients
suffering was organic mercury contamination through frequent consumption of
locally caught seafood. Despite this
finding, fishing was not banned in Minamata Bay until 1968 (11 years later). Fishermen and their families were later found
to be the earliest and most severely contaminated confirming the discovery
(fishermen and their families consumed the greatest amounts of fish).
Researchers have
found that methyl mercury affects the nervous system by targeting and killing neurons
in the occipital cortex and the cerebellum.
This explains some of the symptoms patients experienced, because
occipital lobe is responsible for visual processing and the cerebellum controls
balance and coordinates voluntary movements.
The disease had significant social and cultural
consequences on the Minamata population as well. The state of one’s body reflects the level of
the individuals balance with the external world according to Japanese views of
medicine. As a result, Minamata disease
then called the ‘strange disease’ became stigmatized even in the victim’s own
eyes, and the disease was viewed as something deserved. Victims were
blamed for their conditions, and were ostracized by the town.
The illness was
coined Minamata disease in 1958 by the Kumamoto University Study Group after
the name ‘strange disease’ was deemed an unacceptable medical term. There was a
campaign to change the name of Minamata disease because it gave Minamata a bad
image, reducing the production and tourism sales of Minamata, and promoting
discrimination towards people of Minamata.
As of March 2001, a total of 1,784 people died
from Minamata disease. Although a small number of people died, a great number
of people experienced acute symptoms. Over
ten thousand people received compensation from the Chisso Corporation and by
2004 Chisso had paid a total of 86 million dollars in payments to the sick. However, the Chisso Corporation was very
hesitant to accept responsibility. Chisso emphasized that their decision to pay
condolence money was not an admission of accountability; it was simply a
condolence for the ill and the economically affected (the fishermen’s
association).However, the
company’s negotiation with the recipients of money prohibited any future
demands for compensation even if the company was found responsible for causing
the disease, and included a clause calling for an end to all payments if the
disease’s cause were to eventually be proven not related to the Corporation. To me, these clauses seem like an obvious
indication of the company’s awareness of the relationship between their
The Chisso
factory still exists today, manufacturing chemicals, floppy disks, and
fertilizers. The city of Minamata has
diminished in population. In 1974,
efforts were made to contain contaminated fish by the installation of a three-mile
long net around the Bay. Sludge was also
dredged from the bottom of the Bay in hopes to rid the Bay of mercury and
dumped into a partitioned contaminated corner of the Bay.
In 1997, Mr.
Fukushima, the then governor of the Kumamoto Prefecture announced that the danger
of the recurrence of Minamata disease was gone. His announcement came after the
testing of fish and shellfish from the Bay that revealed mercury concentrations
below the government’s dangerous contamination level. For this reason, the net
around the Bay was removed in 1997, and the fishing was permitted.
Although the net
was removed and the fish were deemed safe, researchers doubt that the Bay will
ever give life to a thriving fishing industry like in the past. As I previously
mentioned, the public is still wary of eating the fish and the few fishermen
left (most have quit/moved/died) actually give their catch to the Chisso
Corporation (who incinerates the fish) in turn for compensation.
I believe the
mercury contamination of the Minamata Bay taught the world of the horrors of
mercury poisoning conveying the need to reduce our consumption of products
containing mercury, regulate hazardous waste disposal, reduce waste and
pollution, protect our waterways and natural environment, increase transparency
between Corporate actions that affect the environment and residents, and that
industrial pollution can be hazardous to others besides workers.
Works Cited
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<http://archive.unu.edu/unupress/unupbooks/uu35ie/uu35ie0c.htm>.
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Minamata Disease It's History and Lessons. N.p.: n.p., 2007. Minamata. Web. 22 Nov. 2014.
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Moore, Colleen F. Silent Scourge: Children, Pollution, and Why
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Minamata." U of Minnesota. SHiPS
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<http://www1.umn.edu/ships/ethics/minamata.htm>.
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Calls Mercury-Poisoned Bay Safe Now." The
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Photos
http://rgsbio09.wikispaces.com/14+Minamata
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