[Reading Science] Is Korean Tap Water Safe? No Safety Without Measurement

The statement "Korean tap water is safe" has long been accepted as a given. However, Korea lacks both the standards and the measurement technology to prove this safety. A special law has been submitted to the National Assembly to address this gap, but the bill remains pending without even being reviewed.

To determine the safety of tap water, it is essential to know what is in it. Recently, when the scientific community discusses tap water safety, the primary focus is on microplastics and nanoplastics. These tiny particles are already at the center of international debate.

In 2017, Orb Media, an American investigative journalism organization, together with researchers from the University of Minnesota, examined 159 tap water samples from 14 countries and found microplastics in about 83% of them.

The results vary depending on the size of the particles used as a standard and the equipment employed. The more detailed the standards and the more sensitive the equipment, the smaller the particles that can be detected. Therefore, a lower number does not always mean "less contamination." It might simply be that smaller particles were not detected at all.

The same applies to Korea. According to investigations by the Ministry of Environment and the National Institute of Environmental Research, between 0.1 and 0.6 microplastics per liter were reported, but all analyzed particles were 20 micrometers (μm) or larger. Particles smaller than this-ultrafine and nano-sized-were not measured at all. The figures so far only reflect results "within the measurable range," and there is no national data for the smallest particle sizes.

The European Union began implementing regulations in September 2023 to phase out the use of microplastics, and the United Nations Environment Programme (UNEP) has recommended surveys of microplastics and nanoplastics in drinking water and the establishment of national management systems. The U.S. Environmental Protection Agency (EPA) has also presented a roadmap for detection technology, analysis standards, and equipment standardization through its nanomaterial analysis program.

The international community has already established the principle that "only countries with measurement standards can speak of safety." However, Korea has not yet reached this standard. The government claims that most plastics are removed during the purification process, but there is no national-level data for ultrafine and nano-sized particles smaller than 20 μm-hundreds to thousands of times thinner than a human hair. Even if the government asserts "there is no danger," under international standards, this is essentially declaring safety based on "an unexamined area."

To fill this gap, in September 2024, Assemblywoman Lee Sujin (Democratic Party of Korea, Proportional Representation) and others sponsored the "Special Act on the Reduction and Management of Microplastics." The bill is currently pending in the National Assembly's Environment and Labor Committee, but due to opposition from businesses regarding regulation and indifference from lawmakers, it has not even been submitted to the subcommittee for review.

This bill represents Korea's first opportunity to establish an institutional framework for the national investigation and management of microplastics and nanoplastics in tap water. However, it is effectively stalled. If the bill continues to be delayed, Korea will remain in the international community as "a country without measurement capability" and "a country that cannot explain with data." It will also be difficult to avoid the assessment that Korea is not prepared to respond to invisible risks.

Even if water appears clear to the eye, if it has not been examined and there are no tools to see it, its safety is essentially only "assumed." The statement "no clear harm has been identified" does not mean there is no risk; rather, it means there is not yet sufficient capability to examine it closely.

What we must choose now is neither to amplify fear nor to indulge in baseless optimism. Instead, we need measurement technology capable of detecting even the smallest particles in tap water, a national standard system to compare the results, and the legal and institutional foundations to implement these measures.

Safety is not achieved through declarations. Only by measuring and verifying can safety be discussed. Korea now stands at the starting line.