A leading expert in polymer and crystal physics at Moscow State University and a member of the Russian Academy of Sciences, Alexei Chochlov, has spoken to RT, saying there is no scientific basis for the claim that polymer nanoparticles are particularly harmful to living organisms. Chochlov argues that microplastic particles are no more hazardous to humans than small wood or cement particles that are present in the environment in much greater quantities.
RT: In recent years, many scientific studies and media reports have been published on microplastic. What exactly is microplastic?
Chochlov: Microplastic is defined as fragments of polymer materials that are smaller than 5 millimeters. These particles can break down into even smaller, micrometer-sized pieces and there are also polymer nanoparticles.
We live in an era dominated by new materials. Just a hundred years ago, the polymer industry barely existed. The widespread use of plastics began in the 1950s and today, around 400 million tons of various plastics are produced worldwide each year.
Some of the most common types of polymers include polyethylene, polypropylene, polyethylene terephthalate, polystyrene and polyvinyl chloride. These materials are used to make plastic films, packaging and more. In essence, we are surrounded by polymer materials; without them, modern life would be unimaginable.
RT: Is it true that microplastic is everywhere, even in our food and water?
Chochlov: The molecular structure of polymers is made up of long chains of monomer units. Interestingly, we are ourselves made of polymers, as proteins, DNA and RNA chains are molecules of this type. As for the presence in the environment, particles from all natural and human-made materials can enter the environment.
Nanoparticles from dust, sand and natural polymers like cellulose can enter cells. Wood itself is essentially a composite material, consisting of cellulose and lignin. Every year, around 2.5 billion tons of wood are produced, while the amount of plastics is only 400 million tons, a very small fraction in comparison to natural polymers.
RT: How does microplastic affect living cells? Can the particles penetrate cells and disrupt their function?
Chochlov: Every material breaks down over time due to environmental factors into smaller particles. All nanoparticles can enter the human bloodstream, not just microplastic. For example, walls gradually crumble to dust and sand, which also enter the human body. There is no evidence that microplastic particles are particularly hazardous.
The human body has been living with ordinary dust for millions of years and it does not harm us. If a particle enters the human body, it is enveloped by biological fluids that contain fragments of bacteria, proteins and the like. Around the particle, a “biocorona” forms, a coating of these fragments, so that it does not affect the human body. This process occurs with all particles, regardless of their composition – including microplastic. For the body, there is no difference between microplastic and dust.
Currently, plastics make up only 15 percent of the total volume of solid waste. That is relatively little and the concentration of microplastic in the environment remains minimal. Laboratory studies claiming harmful effects are often conducted with extremely high concentrations of microplastic that do not reflect reality.
RT: If the environmental impact is not significant, why do you think the media and the public are so concerned about this issue?
Chochlov: Because the media need sensational stories. The idea that wood particles can enter human cells is not shocking, as wood is familiar and no one believes it poses a risk. Synthetic polymers, on the other hand, evoke fear because they are unfamiliar and artificial. However, there is no evidence that they behave differently from other particles.
For example, much has been spoken about the abolition of plastic bottles due to microplastic entering the water. Further studies, however, have shown that the majority of microplastic found in the water comes from polyamides, which are synthetic fibers used in textiles. When these textiles are washed, small particles enter the wastewater and eventually our waterways.
RT: Can we replace plastic containers with alternatives that do not break down into microplastic or are composed of particles that are safe for nature and humans?
Chochlov: There are always alternatives, but they are often much more expensive. And in many fields, such as healthcare, the alternative is not the same. We can, for example, switch from single-use syringes and gloves to reusable variants, but what consequences will that have?
In regions where access to clean water is uneven and sanitary conditions are poor, single-use items and plastic bottles are the only way to prevent poisoning and infectious diseases.
It is, however, of crucial importance that plastic packaging is not carelessly discarded, but rather properly disposed of. Of the 400 million tons of plastic, 300 million end up on landfills or in incinerators, which means that 100 million tons are not disposed of in an environmentally friendly way, a significant problem that warrants attention and corresponding measures.
Moreover, the main sources of microplastic are not plastic utensils or packaging, but rather washed [synthetic] clothing, worn-out tires, city dust and even street markings and ship paint. This suggests that we should give up driving and using washing machines to combat microplastic. But what would that achieve? People cannot forgo hygiene standards and our current infrastructure and logistics cannot offer alternative solutions that meet the needs of society.