An expert advisory panel for the Environment Ministry has endorsed a policy to establish “water quality standards” for per- and polyfluoroalkyl substances, collectively known as PFAS, under the water supply law.

These synthetic chemicals, known for their ability to repel oil and water, pose significant environmental and health risks.

To ensure compliance, regular inspections will be mandated to verify that tap water adheres to the newly established PFAS safety standards.

Given the complexities involved in monitoring and mitigating PFAS, it is crucial that the national government provides comprehensive and meticulous technical and financial support to local authorities and other entities responsible for water management.

In 2020, an interim safety target was set for the combined levels of PFOS (perfluorooctane sulfonic acid) and PFOA (perfluorooctanoic acid) in drinking water at 50 nanograms per liter. One nanogram is a billionth of a gram.

The upcoming policy revision will elevate this interim target to an official water quality standard, planned for implementation in April 2026. Concurrently, a subcommittee of the Consumer Affairs Agency’s advisory council has supported the creation of standard values for mineral water.

Additionally, calculations based on the Food Safety Commission’s daily allowable intake suggest that a 50-nanogram-per-liter standard is appropriate for drinking water.

Comparatively, the World Health Organization (WHO) has set interim targets of 100 nanograms each for PFOS and PFOA, while the United States has established more stringent limits, with maximum contaminant levels for these substances at 4 nanograms each.

PFAS, widely used for their water and oil repellency, heat resistance, and in applications such as waterproofing, firefighting foams, and the manufacturing of semiconductors and automobiles, are known for their persistence in the environment and potential to accumulate in biological organisms.

The production and importation of PFOS and PFOA have generally been banned.

Recent incidents, including leaks from U.S. military bases in Japan and contamination near industrial sites, have intensified safety concerns related to PFAS. In response, there are ongoing initiatives among local governments to negotiate agreements with major semiconductor manufacturers to address and mitigate PFAS pollution.

From a public health perspective, the adoption of stringent legal water quality standards for PFAS is supported by the precautionary principle, which advocates for proactive measures to prevent environmental health hazards.

From fiscal 2020 to 2024, a comprehensive survey of PFAS contamination of drinking water was conducted by the Environment Ministry and the land ministry.

The survey found cases of PFAS levels exceeding the interim target between fiscal 2020 and 2023. No exceedances, however, were recorded in 2024, largely due to successful interventions such as switching water sources.

Despite these improvements, challenges persist. Some businesses opted out of conducting tests or responding to surveys, citing the “low probability” of contamination or “high testing costs” as their reasons. Additionally, the sources of most pollution have not been identified.

To effectively implement the new water quality standards, it is crucial not only to support local governments but also to broaden efforts to pinpoint pollution sources and evaluate the impacts on soil, rivers and well water.

At the municipal water treatment facility in Kibi-Chuo, a town in Okayama Prefecture, tests revealed PFAS levels surpassing the interim target, prompting the testing of residents’ blood at public expense.

Results indicated that more than 80 percent of those tested exhibited blood PFAS concentrations exceeding the level deemed by a U.S. academic institution to increase health risks. While current knowledge is inadequate to establish specific blood concentration standards, addressing these safety concerns is imperative.

For enhanced safety and security, it is crucial to promptly publish test results and disseminate related information.

Moreover, it is essential to gather both domestic and international information on the health impacts and risk assessments of PFAS as well as build a long-term database of baseline data.

--The Asahi Shimbun, Feb. 13