TOKYO -- Four residents within a 500-meter-radius area in a densely populated quarter in this city's Ota Ward died of mesothelioma between 2007 and 2017, and doctors suspect the victims developed the cancer after inhaling asbestos from a factory in operation nearby until around 1980.
The Asbestos Center, a Tokyo-based citizens group following up on asbestos exposure, says it is the first time that multiple cases of mesothelioma, a cancer in the chest, have been found near a former factory in the Japanese capital.
Mesothelioma caused by asbestos develops over decades, and it is feared that more patients could crop up around former asbestos factories across the country. The silicate mineral had been in wide use as inexpensive insulator until it was banned in 2012. The number of deaths by mesothelioma exceeded 1,500 in 2015 -- 1.6 times the figure 10 years ago.
According to doctors and others who saw or knew the four patients, they lived around the factory for seven to 76 years. Three male patients had lived within a 200-meter radius of the factory, and died when they were between 73 and 82. The remaining female patient died when she was 59. She had frequented an area near the factory, which was about 500 meters away from her home.
"None of them had work experience connected with asbestos and they had lived near the factory for long periods of time," said Hirokazu Tojima, a specialist on asbestos-induced illnesses at Tokyo Rosai Hospital, who diagnosed the three male patients. "It's difficult to think of causes other than asbestos dispersed (from the factory)." The 69-year-old elder brother of the female patient confirmed, "My sister used to play with the asbestos that had been piled up around the factory when she was a child."
According to the Ministry of Health, Labor and Welfare, the factory used asbestos to produce cement from 1937 to 1980. Some former workers received work-related compensation for developing illnesses caused by the substance. The facility was eventually shuttered, but a 2008 study by the Ota Ward Office found nearby residents who had developed what is called "pleural plaque," or calcification of lung tissues, caused by asbestos. The company that used to operate the factory declined to comment.
A 79-year-old woman who used to live in a dormitory on the premises of the Ota factory told the Mainichi Shimbun that she and her family are very worried about the potential health effects from the exposure.
"There is this bomb in the form of inhaled asbestos inside of us, and we don't know when and how it will explode," said the woman. She added that the atmosphere around the factory was "always whitish and the dust was everywhere when the wind blew." The woman and her siblings have also developed pleural plaque, and her mother was diagnosed with a lung issue related to asbestos exposure.
In Amagasaki, Hyogo Prefecture, there were five cases of mesothelioma discovered among residents near a former Kubota Corp. factory in 2005. The number of patients has since increased, and Kubota has paid compensation to over 300 people. Other cases have been reported across the country, and a law was introduced in 2006 to provide medical allowances to residents around asbestos factories who developed illnesses but were not covered by the work-related illness compensation system.
Professor Takehiko Murayama of the Tokyo Institute of Technology, a specialist on risk management who has followed the asbestos issue, estimates that the number of deaths caused by the mineral will reach a peak between around 2030 and 2040. Fuyushi Nagakura, director-general of the Asbestos Center, says, "The damage is getting more and more serious. The asbestos issue is far from over."
(Japanese original by Mirai Nagira, Science & Environment News Department)