There are many unrecognized Minamata disease patients who suffered prenatal exposure to mercury, and it is necessary to conduct a fact-finding survey to identify them, medical experts and the patients themselves told a Tokyo symposium.
“Congenital Minamata disease sufferers with catastrophic symptoms are now recognized as the patients at present, but there are cases that unrecognized people develop the disease’s symptoms notably after the age of around 50,” Masazumi Harada, a professor at Kumamoto Gakuen University, said Saturday at the event.
The symposium, in which some 200 people participated, was sponsored by the Japan Federation of Bar Associations.
The Minamata mercury-poisoning disease was officially recognized in 1956, and even unborn children were affected with mercury around that time as their mothers consumed contaminated seafood. These people have reached or will soon reach around 50 now.
“While people affected by mercury as unborn babies or little children have managed to control their poor health and have struggled at their workplaces, it is quite difficult to prove they have Minamata disease” because their symptoms are not discernible to the eye, said Harada, who has been involved in the issue as a doctor.
He stressed the necessity for authorities of examining how the people have been living, including their health conditions, adding, “Otherwise, they will remain left behind without sufficient redress.”
Minamata disease, a neurological affliction, was caused by mercury-laced wastewater from a synthetic resin factory of Chisso Corp. in Minamata, Kumamoto Prefecture, which poisoned fish. A similar pollution-caused disease was confirmed in Niigata Prefecture in 1965 that was found to be caused by wastewater from a plant of Showa Denko K.K.
Reflecting Harada’s comments, Miyoshi Arashi from Kagoshima Prefecture, near Kumamoto, told the symposium, “I have been in delicate health since childhood, but I never thought it was because of Minamata disease.” Born into a family of fishermen, Arashi, 49, ate fish every day.
But his umbilical cord, which his mother kept, showed a significantly high mercury level, prompting him to apply for official recognition as a Minamata disease patient in 2001 for medical benefits “as I finally realized my poor health was caused by mercury.”
“My application has been put on hold since then, but I think my health condition — I don’t have strength in my limbs and I feel dragged down — has deteriorated year by year,” he said.
Tamotsu Tsugawa, 56, who was also born into a family in the fishing industry, is another sufferer.
“I’ve often stumbled, even on small steps, since my childhood and I was not good at physical exercise. . . . I just believed I was inferior to others,” Tsugawa said.
While he was reluctant to recognize himself as a Minamata disease patient mainly because he feared discrimination, he has applied for medical benefits, encouraged by people around him.
“I hope that I could lead an independent life and marry so I could establish my own family,” he said. “I think I could have another life if I were in good health.”
Both Arashi and Tsugawa earn a living by doing part-time jobs.
At the symposium, meanwhile, the JFBA reported the results of its field survey on health and living conditions of Minamata disease sufferers that was conducted through interviews with 107 people in Kumamoto and Kagoshima prefectures in June. Of the 107 in their 40s to 70s, 105 are unrecognized patients.
It showed even unrecognized disease patients have suffered either sensory and motor disorders or visual field constriction, while all of them have numbness in their limbs.
Concerns were expressed over the future of the congenital patients, with one interviewee noting in a survey slip, “I hope people will be aware that there were babies who were affected by mercury in their mothers’ wombs and took mercury-contaminated breast milk, and that there were mothers who unknowingly gave poisonous breast milk to their babies.
“People need to realize (the babies) have been plagued by mercury for more than 50 years and their suffering will get worse,” the interviewee added.