The Invisible Bill · Episode 7 of 12 · 22 min
The Cat-Dancing Disease
In 1956 in Minamata, Japan, cats began to convulse and children arrived at a factory hospital with a neurological disease no one could name. The cause was methylmercury discharged into the bay by the Chisso factory for three decades. The company's own hospital director proved the link in 1959, the result was suppressed, and the town's name now marks a global mercury treaty.
Who's who
- Hajime HosokawaChisso hospital director who reported the disease and ran the cat experiment
- Kiichi YoshiokaChisso president during the denial and suppression
- Masazumi HaradaPhysician who documented congenital Minamata disease
- W. Eugene SmithPhotographer who documented the patients from 1971 to 1974
- Aileen Mioko SmithCollaborator who lived in Minamata with Smith
Where it happens
- Minamata Bay, Kumamoto Prefecture, JapanWhere Chisso discharged methylmercury for decades
- Shiranui Sea, JapanContamination spread along its coast after 1958
- Agano River, Niigata, JapanSite of Japan's second Minamata disease outbreak
Timeline
- 1932Chisso begins producing acetaldehyde with a mercury catalyst.
- May 1956Hosokawa reports an unknown central nervous system disease; the official discovery date.
- October 1959Cat 400 shows factory wastewater causes the disease; the finding is suppressed.
- December 1959Chisso pays token "sympathy money" with a waiver of future claims.
- 1973Patients win their lawsuit against Chisso.
- 2013The Minamata Convention on mercury is adopted.
Still debated
No single count of victims exists: certified patients, those compensated by settlement, and people with methylmercury-related impairment are three differing, expanding groups. How much Chisso understood before 1956, and the amount of mercury discharged, are interpretive; legal fights over who is owed continue.