Chemicals potentially harmful to human health, collectively known as PFAS, were detected in about 20 percent of tap water in Japan, though no samples contained the maximum permissible amount tentatively set by the government, a survey showed Friday.
In the government’s first large-scale survey covering even small water utility companies, the chemicals were detected in water samples from 332 water companies in 46 of the country’s 47 prefectures out of 1,745 companies surveyed.
The Environment Ministry and the Ministry of Land, Infrastructure, Transport and Tourism has been conducting tap water surveys focused on PFAS containment since 2020 after the widely used and long-lasting substances were detected in filtration plants and rivers across the country and concerns grew about their possible links to cancer risks.
PFAS, or polyfluoroalkyl substances, used in various products such as non-stick cookware and water-repellent clothing, are known as “forever chemicals” because they have components which break down very slowly over time and can accumulate in people, animals, plants and the environment.
The government currently sets a provisional cap of 50 nanograms per liter for the two representative forms of PFAS, perfluorooctanesulfonic acid, or PFOS, and perfluorooctanoic acid, or PFOA.
None of the samples contained the substances exceeding 50 nanograms in total, but those from three water utilities in Aichi Prefecture, Nagasaki Prefecture, and Hokkaido were found to have between 47 to 49 nanograms of the chemicals, according to the survey.
The ministries conducted the survey between May and September. Results on water supplied exclusively to certain facilities have not been finalized.
In past surveys, cases in which PFAS levels exceeded 50 nanograms came to 11 in fiscal 2020, five in fiscal 2021, four in fiscal 2022, and three in fiscal 2023.
Koji Harada, an associate professor of environmental studies at Kyoto University, said the government should legally require all water utilities to check their water for PFAS and set legally binding upper limits.
