How long ago did humanity realize that the problem of ocean pollution with microplastics exists and is quite acute?
According to existing estimatesby the end of 2015, only 8.3 billion tons of polymers were produced, of which only 600 million tons are recycled and only 100 million tons are recycled more than once. 2.5 billion tons remain in use, while 800 million tons are disposed of (burnt or buried). The rest of the garbage, which is about 4.9 billion tons, simply remains in the environment, polluting it. Polymers decompose rather slowly, and the question of where microplastic particles come from – and these are polymer particles less than 5 millimeters in size – actually remains open. Some studies show that the main reason for the appearance of microplastics in the oceans is the work of sewage treatment plants and washing machines. With each wash, clothes can lose up to 0.3% of their weight, which means that small particles, fibers, “detach” from it. All these polymers, both synthetic and natural, end up in the ocean. There is even an opinion that up to 60% of all microplastics at the bottom of reservoirs are synthetic fibers. In addition, small particles are formed during the decomposition of polymers. For example, used plastic packaging, which is not recycled but sent to the trash, gradually – over a very long time – degrades under the influence of ultraviolet radiation, oxygen and free radicals that are in the environment. In the ocean, in addition to these factors, polymers are mechanically affected by waves and wind, as well as an aggressive salty environment; under these conditions, the grinding and formation of microplastic particles occurs faster. that up to 60% of all microplastics at the bottom of water bodies are synthetic fibers. In addition, small particles are formed during the decomposition of polymers. For example, used plastic packaging, which is not recycled but sent to the trash, gradually – over a very long time – degrades under the influence of ultraviolet radiation, oxygen and free radicals that are in the environment. In the ocean, in addition to these factors, polymers are mechanically affected by waves and wind, as well as an aggressive salty environment; under these conditions, the grinding and formation of microplastic particles occurs faster. that up to 60% of all microplastics at the bottom of water bodies are synthetic fibers. In addition, small particles are formed during the decomposition of polymers. For example, used plastic packaging, which is not recycled but sent to the trash, gradually – over a very long time – degrades under the influence of ultraviolet radiation, oxygen and free radicals that are in the environment. In the ocean, in addition to these factors, polymers are mechanically affected by waves and wind, as well as an aggressive salty environment; under these conditions, the grinding and formation of microplastic particles occurs faster. gradually – over a very long time – degrades under the influence of ultraviolet radiation, oxygen and free radicals that are in the environment. In the ocean, in addition to these factors, polymers are mechanically affected by waves and wind, as well as an aggressive salty environment; under these conditions, the grinding and formation of microplastic particles occurs faster. gradually – over a very long time – degrades under the influence of ultraviolet radiation, oxygen and free radicals that are in the environment. In the ocean, in addition to these factors, polymers are mechanically affected by waves and wind, as well as an aggressive salty environment; under these conditions, the grinding and formation of microplastic particles occurs faster.
– So far, there are no such technologies, but there are certainly arguments on this topic. Now scientists are faced with a dilemma, which polymers are more environmentally friendly: quickly or slowly decomposing. If we talk about fast-degrading polymeric materials, then among them there are many on the market that are created by mixing synthetic polymers with biodegradable compounds, such as starch. It cannot be unequivocally stated that we bring more benefits to nature by using the so-called biodegradable plastic bags, since under the influence of air the starch that is part of it is hydrolyzed, due to which the mechanical properties of the bag deteriorate, and the product itself quickly breaks down into small pieces. Accordingly, by throwing away such a bag, we lead to a very rapid formation of microplastics.
– Are there any differences between microplastics, which are formed as a result of the decomposition of polyethylene, polypropylene, polystyrene and other polymers?
— These molecules, depending on the chemical structure, will decompose somewhat differently. For example, research shows that up to 200 different compounds are formed during the decomposition of polyethylene, one of the simplest polymers. All of them are quite harmless, and, in principle, to say that microplastic particles themselves are harmful is a strong exaggeration. Most polymers are chemically inert and chemically resistant. Microplastics can be harmful rather from the point of view that it can act as a carrier for other, already dangerous, pollutants, for example, heavy metals. If we talk about which polymers are the most harmful, then polyvinyl chloride can be distinguished here, since it is a representative of organochlorine compounds, and they themselves are quite toxic. In addition, PVC is practically not recycled.
— Yes, but it must be admitted that there is not much reliable scientific data describing the impact of microplastics on living organisms. First of all, no one compared microplastics with other possible carriers of pollutants, such as dust or fine sand. Another question, of course, is the size of these particles. Last year, an article was published that compared nanoparticles and microparticles of plastic (comparable to the size of viruses and bacteria, respectively). It turned out that, although both groups, according to the modern classification, belong to microplastics, there is a huge difference between them. Nanoparticles have a large specific surface area and, accordingly, can adsorb pollutants more per unit mass. In addition, they interact more easily with cells and penetrate various natural barriers, such as the blood-brain barrier. In addition, it is worth noting that, in principle, it is not the polymers themselves that are harmful, but the additives that are present in them. These can be plasticizers, stabilizers, antioxidants, fire retardants. They are often toxic. And the smaller the particles, the faster the toxic substances are released from them.
Recycling is considered one of the most effective ways to combat the accumulation of plastic waste. Does this process produce microplastic particles?
– The formation of microplastics during the processing of polymers is not the biggest problem, in my opinion. Of course, plastic microparticles can form, especially when considering the mechanical processing of polymers. But technically, this can be dealt with with the help of a more accurate process and special devices for capturing. The more important problem of mechanical processing is that in this case we mix different polymers, and their chains are inevitably shortened. This means that the properties of plastics will change. That is, during mechanical processing, we cannot guarantee the final purity and quality of the polymer. But there is another type of processing – chemical. In this case, using various catalysts at elevated temperature and pressure, useful low molecular weight compounds can be obtained. Now, for example, thermolysis produces various oils that can be good fuel additives. These technologies must be further developed to become cheaper.
– Often, when talking about ecology, they use a comparative assessment, saying, for example, that one area is more polluted than another. How, from this point of view, can one assess the degree of microplastic pollution of the oceans washing the territory of Russia, as well as its continental waters?
“Unfortunately, there are very few Russian studies on microplastics for various reasons. At the same time, no one will explore our seas, oceans and inland waters except us. This year Khakassia hosted the First All-Russian Conference on Environmental Pollution with Microplastics MicroPlastics Environment – 2022, where experts interested in the problem of microplastics presented their reports. They all come to the conclusion that microplastics are found in principle everywhere. It is found in all oceans and in all bodies of water. It was found in Baikal, which is a natural heritage not only of Russia, but of the whole world. Perhaps there is some truth in the fact that Russia is bordered by oceans that are relatively less polluted with microplastics, since we have a rather long border along the Arctic Ocean, in which there are no garbage plastic “islands”, typical, for example, for the Atlantic. In my opinion, even if this is true and the concentration of microplastics in our country is less than in other water areas, then this is just a matter of time, because the problem of ocean pollution is transboundary. Microplastics can persist in the natural environment for a long time, and therefore migrate with water and air currents. For me personally, the issue of microplastics is perceived as a kind of deferred problem, since now a person is not yet faced with those concentrations that could be dangerous. And right now is the right time for scientific research, in order to understand the real threats, as well as to think about the measures that need to be taken to protect future generations from the danger associated with microplastics. The activity of Rosprirodnadzor is very important,
“Of course, the best scenario is one in which humanity learns to manage the decomposition of polymers to such a state when they break down into small particles that are quite natural for nature, and will make the most of the multiple processing of polymers. In addition, we should change our attitude towards polymers. We throw away used polymers not because they are bad, but because they are cheap. I have great hope for young people, because it is young people who are now most concerned about the environmental approach to the materials used. This includes separate waste collection and environmental education. To solve the problem, the first step is to raise the level of the discussion. Society needs to know more about polymers. The worst case scenario will come if we simply do not think about what we consume and the fate of what we have produced.
