Masazumi Harada, leading researcher of Minamata disease, dies at 77

June 12, 2012


Masazumi Harada, a former professor at Kumamoto Gakuen University and a leading researcher of Minamata disease, died of acute myeloid leukemia on June 11. He was 77.

Minamata disease is a neurological disorder caused by the intake of methyl mercury accumulated in fish and shellfish in the 1950s and 1960s, mostly in communities in and around Minamata Bay, Kumamoto Prefecture. The methyl mercury was contained in industrial wastewater discharged into the sea by Chisso Corp. About 3,000 people have officially been recognized as patients, although the real number of those afflicted is estimated in the tens of thousands.

Harada was born in 1934 and grew up in Kagoshima Prefecture. He began research on Minamata disease in Minamata in 1961, a year after he obtained a medical practitioner's license at Kumamoto University.

Harada discovered the presence of a fetal Minamata disease that is caused by poisoning by organic mercury in the mother's womb. That finding overturned the belief, broadly shared at the time, that placentas did not transfer toxic substances to fetuses.

Harada made the rounds of neighboring coastal areas facing the Shiranui Sea to diagnose and treat patients, which helped define the geographical spread of Minamata disease. He consistently testified from the viewpoint of victims of Minamata disease during lawsuits filed by patients in different parts of Japan.

After the November 1963 explosion at the Mitsui Miike coal mine in Omuta, Fukuoka Prefecture, the worst coal mine accident in the postwar period, which claimed 458 lives, Harada followed up with carbon monoxide poisoning patients for 40 years and reversed the accepted textbook theory that the poisoning had little aftereffects.

He also studied the Kanemi Yusho incident--the largest food pollution incident in Japan--in which a dioxin was generated in edible oil produced by the Kanemi Soko company and impaired the health of about 14,000 consumers in 1968. Harada investigated the health effects in Goto, Nagasaki Prefecture, and elsewhere, and directed public attention to a need to help those afflicted.

He also served as the leader of a Japan-Vietnam joint research project on the lingering health effects from defoliants used in the Vietnam War and, jointly with medical practitioners in Vietnam, studied the health of more than 7,400 local residents in 1988-89.

"Where Japan failed will serve as a lesson to be learned by the world," Harada said during the last interview he granted with an Asahi Shimbun reporter on June 9.

He did not hold back his anger in protesting the government's move to stop accepting applications for Minamata disease relief at the end of July this year.

"(The government) has forgotten about the patients who have suffered for more than 50 years," Harada said.

One of his dying wishes was to have his ashes dispersed in the sea off Minamata, a place he frequented for half a century.

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Masazumi Harada (Asahi Shimbun file photo)

Masazumi Harada (Asahi Shimbun file photo)

  • Masazumi Harada (Asahi Shimbun file photo)

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