A research team from Columbia University in the United States, published a paper , in the Proceedings of the National Academy of Sciences in January 2024, revealing that 24,000 particles of seven types of plastic were found in 1 liter of bottled water, with nano-plastics accounting for 90% of them.

Plastic pollution is a global concern, with approximately 4 billion tons produced annually and over 30 million tons discarded into oceans and land each year.

Plastics do not easily decompose and eventually break down into microplastics, further breaking down into nano-plastics.

Microplastics, with a size of 5 mm or less, primarily originate from the breakdown of plastic waste entering the ocean.

Recent discoveries in Antarctica, the Arctic, and high-altitude areas such as the Alps have confirmed the global extent of microplastic pollution.

Nano-plastics, being smaller than 1 μm, can penetrate cells and tissues, raising concerns about potential toxicity.

In 2018, researchers from New York State University found 325 microplastic particles per liter of drinking water.

However, this new study focused on measuring even smaller nanoplastic particles, revealing an average of 240,000 nanoplastic particles per liter of bottled water, 10 to 100 times higher than previous estimates.

To detect previously challenging nano-plastics, the research team utilized Raman spectroscopy microscopy.

They explained that by emitting lasers in two directions and observing the resonance of molecules, they confirmed 240,000 plastic particles in 1-liter samples from three types of bottled water.

Of these, 90% were nano-plastics, with the rest being microplastics.

The predominant plasticparticle was polyethylene terephthalate (PET), commonly found in water bottles.

The researchers suggested that the act of squeezing or exposing PET bottles to heat may release tiny fragments into the water.

Additionally, frequent opening and closing of PET bottle caps were linked to plastic wearing off and entering the water.

However, nylon, a type of polyamide, was more abundant than PET, and the researchers suspected it might originate from plastic filters used to purify water before bottling.

Other plastics such as polystyrene, polyvinyl chloride, and polymethyl methacrylate were also identified.

The entry of plastic particles into the human body can pose various health risks.

Both microplastics and nano-plastics have been reported to have extensive and hazardous effects on the body's major systems, including oxidative stress, inflammation, immune dysfunction, biochemical and energy metabolism changes, cell proliferation disorders, disruption of microbial metabolic pathways, abnormal organ development, and potential carcinogenicity.

Nano-plastics, due to their smaller size, may pose a greater threat as they can directly enter the gastrointestinal or liver tract, circulate through blood vessels, and potentially reach the heart or brain.

However, the exact level of danger posed by these tiny plastic particles is still not precisely known, and the researchers emphasized the need for further investigation into the potential harm caused by the significant presence of microplastics in the human body.

Seokhyun Chin

Grade 11

Choate Rosemary Hall