"Swallowed One Card Every Week"... Microplastics Become a Time Bomb [Reading Science]

Microplastics. Stock photo.

[Asia Economy Reporter Kim Bong-su] "You are currently swallowing an amount of microplastics equivalent to one credit card per week. Someday, it could become a time bomb for the human body and the ecosystem."

Last year marked the '100 years of polymers.' It has been 100 years since German scientist Staudinger first introduced the concept of polymerization in 1920. Polymer materials, represented by plastics and petrochemical products, have brought both heaven and hell to humanity. Various polymer materials used in daily life have provided humanity with the greatest convenience, cleanliness, and durability in history. On the other hand, plastic islands floating in the middle of the Pacific Ocean and contamination of soil, water, and ecosystems by microplastics have become ticking 'time bombs' that could explode at any time.

◆What are microplastics?

Microplastics ranging from 100 nanometers (nm) to 5 millimeters (mm) are classified into primary microplastics, which are originally made small such as in cosmetics and toothpaste, and secondary microplastics, which are generated by the breakdown of tires, styrofoam, paint, vinyl, etc. Primary microplastics are banned worldwide. In South Korea, the use of microplastics in cosmetics has been restricted since January 1 of this year.

As of 2010, about 275 million tons of plastic were produced worldwide, of which about 8 million tons were discharged from land into the sea and transformed into microplastics. The amount of plastic dumped into the ocean is more than the 6.5 million tons of tuna humans catch and consume annually worldwide. Recently, plastic waste captured by a deep-sea exploration vessel in the Mariana Trench, the world's deepest trench, became a hot topic. In South Korea, last month, a KBS news team investigated the Han River estuary and found that decades-old plastic waste such as snack packaging from land was caught in fishermen's nets in tens of kilograms at a time, indicating worsening marine pollution. Occasionally, turtles or whales are found dead with their throats clogged or stomachs full of plastic.

One styrofoam box lid discarded in the sea generates about 300.7 billion ultra-fine and microplastics per year. Especially after the COVID-19 pandemic, plastic use worldwide has surged in the past one to two years. The production of disposable spoons increased by 25.2% in 2020 compared to 2019, and disposable forks increased by 64.1% during the same period.

Microplastics that have been broken down by abrasion, friction, light, and microorganisms in nature are primarily absorbed by tiny organisms such as water fleas, mistaking them for food. These are then eaten by intermediate predators like minnows and anchovies. As they move and accumulate along the food chain, they become highly concentrated in top predators such as sharks. Very small microplastics among fine dust can be blown by the wind into the sky.

◆Neurotoxicity and Internal Damage

What impact do microplastics have on the Earth's ecosystem? Recently, the U.S. National Oceanic and Atmospheric Administration announced that among about 700 fish caught in the North Atlantic, 11% contained microplastics. Small organisms with accumulated microplastics experience neurotoxic effects that paralyze their nerves, significantly reducing their travel distance and speed. Damage such as mucous membrane irritation, immune system impairment, and abrasions in the digestive tract have also been confirmed.

Microplastics are a 'potential time bomb' for humans as well. Recently, fecal tests on eight individuals from Europe, Russia, and Japan detected 20 microplastics per 10 grams. In Italy, 12 microplastic fragments were found in the placenta of a pregnant woman: 5 in the fetus, 4 in the mother, and 3 in the amniotic membrane. According to research by the World Wide Fund for Nature (WWF), a person swallows about 2,000 microplastics per week, equivalent to about 5 grams, roughly the size of one credit card. The main ingestion routes are water (1,769 pieces), crustaceans (182 pieces), salt (11 pieces), and beer (10 pieces). When organisms ingest microplastics, damage to the digestive tract or absorption and accumulation of plastic chemicals in the body can cause various endocrine disruptions.

On the 28th of last month, Park Jun-woo, head of the Environmental Risk Research Department at the Safety Evaluation Research Institute, said at a meeting hosted by the Korean Federation of Science and Technology Societies, "The effects on the human body are still under study, so no clear conclusions have been reached yet," adding, "Fish affected by microplastics show significantly reduced movement, making them easy prey, so the cumulative effect through the food chain is greater. Research shows that microplastics cause neurotoxicity and intestinal damage, destroying the internal organs of organisms. Many microplastics have also been found in human corpses in the U.S."

◆Use Less and Avoid Discarding

What is the solution? There is no choice but to produce and discard less than now. Pollutants should not be discarded anywhere but collected properly for recycling, and alternative materials must be produced. Shim Won-jun, senior researcher at the Korea Institute of Ocean Science and Technology, pointed out, "It is possible to filter microplastic particles from water or soil, but microorganisms die and microplastics are widely distributed on Earth, so it is practically impossible. We must reduce them at the source. Large and medium-sized plastic waste should not be left in nature but removed quickly."