TOKYO -- Cancer-causing organic fluorine compounds such as perfluorooctanesulfonic acid (PFOS) have been found in above-national-average concentrations in the blood plasma of residents in two cities in Tokyo's Tama region, a nonprofit organization has announced.
The tap water in the two suburban cities contains concentrations of PFOS above the national government's provisional target figure, and the organization, Japan Endocrine-disruptor Preventive Action (JEPA), has submitted a recommendation to the national and Tokyo Metropolitan governments to conduct health surveys of Tama region residents.
The Ministry of Health, Labor and Welfare established a provisional target figure for PFOS and a similar substance, perfluorooctanoic acid (PFOA), at a total of 50 nanograms per 1 liter of tap water in April 2020. It requested that all local governments stop drawing water from wells that exceeded the target figure.
In August, JEPA obtained the cooperation of 11 residents each in areas where water is supplied from the Fuchu Musashidai water purification plant in the Tokyo suburb of Fuchu, and the Higashi Koigakubo water purification plant in the capital's suburb of Kokubunji, both in the Tama region, and looked into the concentration of PFOS and other chemicals in their blood plasma. Those two plants have used well water. It has been reported that for years, levels of PFOS and other substances exceeding target figures had been found in tap water supplied by the two water purification plants.
The PFOS concentration in the blood plasma of the 11 residents from Fuchu averaged 18 nanograms per 1 milliliter, which is about 2 times the national average, while the PFOS concentration in the blood plasma of the 11 people from Kokubunji averaged 12 nanograms, which is about 1.5 times the national average. JEPA says that it is not an amount that will have health effects right away.
At a press conference in Tokyo, Yuko Nakashita, head of JEPA, said, "In the Tama region, there were multiple other water purification plants in the past where figures exceeded the target. The central government should carry out continuous health surveys of residents living in these areas."
PFOS hardly degrades naturally, and accumulates in the body. It has been used in fire-extinguishing foam and cooking equipment, but from 2018 its production and import for any use has been banned under the Act on the Evaluation of Chemical Substances and Regulation of Their Manufacture, etc. According to a survey report on rivers and groundwater released by the Ministry of the Environment in June, the figure exceeded the target at 37 sites across Japan, including near U.S. military bases and industrial districts.
(Japanese original by Toshiyuki Suzuki, Science & Environment News Department)