PFAS levels exceed standard at 242 locations in Japan

A Japanese government survey conducted in fiscal 2023 has found concentrations of potentially harmful PFAS chemicals in rivers and groundwater exceeded the country's provisional standard at 242 locations nationwide.

The environment ministry released the survey results for fiscal 2023 at an expert panel meeting on Friday.

PFAS, or perfluoroalkyl and polyfluoroalkyl substances, were once used for water-repellent finishing and foam-extinguishing agents. The country banned the production and import of PFOS and PFOA, the two most representative forms of PFAS, by 2021.

The government has set a provisional target for the combined amount of PFOS and PFOA at 50 nanograms per liter of tap water and rivers.

The tests were conducted by 39 prefectures at 2,078 sites in fiscal 2023, which ended in March 2024. The results showed that the levels of PFOS and PFOA exceeded the provisional target at 242 locations in 22 prefectures, including Tokyo, Osaka and Okinawa.

The highest concentration was found in groundwater in Settsu City in Osaka Prefecture at 26,000 nanograms per liter, 520 times the standard, followed by groundwater in Higashihiroshima City in Hiroshima Prefecture at 15,000 nanograms.

PFAS concentrations exceeded the standard at all 13 sites surveyed in the town of Kadena, Okinawa Prefecture, home to many U.S. military bases, according to the survey.

The ministry said it has determined the source of the two chemicals at only four of the tested locations so far, and has required water service operators to dilute river water before it is put into the water supply.

The expert panel approved a plan to mandate the regular testing of tap water and change the 50-nanogram level from a provisional target to a legal standard. The ministry will revise the necessary ordinance, and enforce the new standard from April 2026.