“Over 100 Million Nanoplastics per mL Detected in Bottled Water, Study Finds”

[헤럴드경제=채상우 기자] A study has found that more than 100 million nanoplastics per mL have been detected in bottled water.

Nanoplastics are pieces of plastic smaller than 1 μm (micrometer, 1/1000th of a mm) in diameter.

An international research team from Norway’s University of Science and Technology, Nankai University of China, and Ghent University of Belgium recently published a paper measuring the concentration of nanoplastics in bottled water in the journal ‘Environmental Science and Technology’.

The research team conducted an experiment by purchasing bottled water products from four brands distributed in the Norwegian market.

The research team filtered bottled water samples through a glass fiber filter membrane with a diameter of 100 nm (nanometers) and analyzed the water that passed through the filter membrane. In addition, nanoplastic caught on the filtration membrane was observed with an electron microscope.

As a result of the analysis, 1 mL of the sample contained an average of 166 million nanoplastics.

The average size of nanoplastics was 88.2 nm.

Nanoparticles detected in bottled water. The small bar at the bottom left indicates a length of 200 nm. [자료: ES&T, 2023]

If adults drink 2L of water per day and children drink 1L of water per day, the research team explained that it can be seen that adults consume 120 trillion nanoplastics per year and children 54 trillion nanoplastics per year through water.

The number is much higher than the level of microplastic intake known so far.

In the case of microplastics with a size of more than 1㎛ and less than 5㎜, there are 0.1 to 10,000 pieces per 1mL of bottled water.

The research team pointed out that “the nanoplastic present in commercially available mineral water bottles may be contaminated by the bottle itself, but contamination of water sources or product packaging may also occur.”

On the other hand, there is also a study that a nylon bag for food or a disposable beverage cup coated with low-density polyethylene (LDPE) is exposed to a high temperature of 100 degrees, releasing 1 billion nanoplastic particles per mL.

In this experiment, the research team applied ‘Surface-Enhanced Raman spectroscopy (SERS)’, which was developed relatively recently for the detection of nanoplastics.

This is because existing methods are judged to be unsuitable for studying very small nanoplastics.

Disposable cup nanoplastic, when exposed to hot water at 100 degrees for 20 minutes, 1 trillion nanoplastics per L and 1 billion nanoplastics per mL are eluted.

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