Nearly 90% of bottled spring water contains microplastics, gov't study suggests

The Ministry of Environment said on Tuesday that bottled spring water contains, on average, 1.32 pieces of microplastics per single liter.

A customer walks by a stand selling bottled spring water in a supermarket in downtown Seoul last year. [YONHAP]

The Ministry of Environment said on Tuesday that bottled spring water contains an average of 1.32 pieces of microplastics per single liter.

Microplastic refers to tiny plastic particles with a diameter between one micrometer and five millimeters. The ministry’s finding only includes microplastics with diameters longer than 20 micrometers — or one-fifth the thickness of a strand of human hair.

The National Institute of Environmental Research, run by the Environment Ministry, said 88.1 percent of tested water contained microplastics, mostly consisting of polyethylene terephthalate, polypropylene and polyethylene, after analyzing more than 30 spring water products sold on the market between 2022 and last year.

The finding shows that potable spring water carries slightly fewer microplastics than ocean water near coastal surfaces, with 1.82 pieces of microplastics per liter. The concentration in ocean water is around 66 percent of the safety limit, which is considered hazardous to marine species.

Some beverages were found to carry more microplastics than spring water. In 2022, the Ministry of Food and Drug Safety said that around 40 pieces of microplastics with diameters longer than 20 micrometers were found per liter in fruit-flavored drinks for sale in the domestic market. Beer had around 10 pieces of microplastics per liter, the ministry said.

Particles of microplastics are placed on a human finger. [UNITED NATIONS ENVIRONMENT PROGRAMME]

The domestic spring water market has grown exponentially over three decades after the Drinking Water Management Act was legislated. The 72.7 billion won ($53 million) market in 1995 rose to 2.3 trillion won last year.

In a 2021 survey conducted by the Environment Ministry, 32.9 percent of some 72,460 households nationwide buy spring water to drink.

Yet, the recent finding does not provide a complete picture of microplastics because it did not include microplastics with a diameter of less than 20 micrometers or much smaller nano-plastics with diameters of less than one micrometer.

Prof. An Youn-joo from Konkuk University’s Environmental Health Science Department said the recent research has a “limit” in comprehending the exact amount of microplastics with a diameter of less than 20 micrometers since they were left out of the study, noting that the tiniest ones are a significant concern.

Earlier this year, a research team from Columbia University found that approximately 240,000 pieces of nano-plastics are in every liter of spring water. The finding was shared by the U.S. Proceedings of the National Academy of Sciences.

A stall packed with bottled spring water at a supermarket in downtown Seoul in March last year [YONHAP]

The harmfulness of microplastics and nano-plastics to human bodies has not yet been substantiated.

Academia and researchers have warned that microplastics could be transported to the heart and brain, and at worst, even to the fetus in case of pregnancy. They cautioned that accumulated microplastics inside the body could negatively affect one’s health.

In March, the medical school of the University of Campania Luigi Vanvitelli published study results that suggested patients who had microplastic in their carotid arteries have a 4.53 times higher chance of dying of cardiac arrest or stroke.

The Environment Ministry acknowledged the limit in detecting tinier microplastics due to the absence of an international standardized methodology. The ministry said it will introduce equipment that can detect microplastics with a diameter of a single micrometer next year.

The international standard for analyzing microplastics is set to be announced by the International Organization for Standardization next year.

BY JEONG EUN-HYE, LEE SOO-JUNG [lee.soojung1@joongang.co.kr]