Microplastic: should we be afraid of it in food

Although it is not very noticeable at first glance, microplastics have long become an integral element of modern life, polluting the environment. It is found in the seas, inside various organisms, and what is more terrible - inside a person. Where does microplastic come from, can we protect ourselves from it, and how dangerous is it for our health?

What is microplastic

Microplastic is a heterogeneous mixture of materials of various shapes in the form of fragments, fibers, granules, flakes ranging in size from 0.1 microns to 5 mm. In simple terms, microplastic is any plastic, only in microscopic size.

There are two types of microplastics in their origin: primary and secondary. Primary - these are plastic particles that were originally micro-sized. It is formed in different ways:

  • in the process of washing synthetic clothes (35% of all microplastics);
  • as a result of car tire wear (28%);
  • contained in smog (24%).

In addition, plastic microgranules can be contained in cosmetics.

Recycled microplastics are formed when larger pieces of plastic break down. Experts have calculated that from 69% to 81% of this substance accumulates in the waters of the seas and oceans. Most often, the source of such microplastics is old fishing nets, bottles and plastic bags, which, under the influence of UV radiation, as well as sea water, decompose into smaller particles.

Scientists analyzed the chemical composition of microplastics. It turned out that the vast majority of this substance is particles of polypropylene, polyethylene, PVC (polyvinyl chloride) and polystyrene. In smaller quantities, particles of nylon, polyester and acrylic fibers were found, the sources of which, according to experts, can be synthetic clothing. But the most common are polyurethane and PET (polyethylene terephthalate) microparticles.

What can contain

Figuratively speaking, the main vehicle for microplastics is water. So, during washing, all synthetic microfibers fall into the water. In the case of plastic particles on roads and in the form of urban smog, they are washed away by rain. And there is also plastic garbage, which also decomposes into microparticles under the influence of chemical, biological and physical factors.

Unfortunately, even the most modern sewage treatment plants cannot catch this type of pollution, so most microplastic particles end up in rivers, and then into the seas and oceans. According to experts, the world's oceans can contain from 93,000 to 268,000 tons of microplastics. About 40 tons of microplastics enter the Baltic Sea alone every year. According to other estimates, from 2% to 5% of the plastic produced in the world penetrates into the water.

It is difficult for scientists to determine the exact amount of plastic in the oceans, as some of these materials are heavier than water and sink to the bottom, which complicates the calculation. And the one that remains on the surface accumulates heavy metals and other toxic substances contained in sea water.

But microplastics are not only found in water. It is also present in the air - the so-called plastic dust that we inhale. Microplastics enter the soil from oxo-biodegradable foil, which is broken down into microparticles under the influence of the sun. Microplastics are increasingly being added to cosmetic products such as body lotions, face creams, make-up products, toothpastes, scrubs, and shampoos. In different types of products, the proportion of microplastics can range from 1% to 90%.

Microplastics in food: is it possible

Researchers from the University of Vienna analyzed the composition of the faeces of 8 people from around the world (from Austria, Finland, Holland, Japan, Great Britain, Italy, Poland and Russia) for the presence of plastic microparticles in them. During the week preceding the collection of biomaterial for laboratory analysis, the participants in the experiment kept a diary of food intake. None of the subjects were vegetarians, and 6 of them regularly ate sea fish.

The results of the experiment surprised even scientists. Nine types of plastic were found in each stool sample. The found fragments were from 50 to 500 microns in diameter. The researchers calculated that, on average, there are about 20 microscopic plastic particles in every 10 g of feces. Most often it was polypropylene and polyethylene terephthalate (PET). The results of the study confirmed the guesswork of scientists that microplastics can also be found in human bodies. But how do microscopic plastic particles get into our bodies?

How microplastics enter the human body

Plastic enters the human body with food. Scientists have found that its microparticles can be found in fish and seafood, sea salt, beer, and even bottled water.

Water

Scientists claim that microplastics are ubiquitous, including the plumbing. But if someone believes that only tap water is dangerous, then they are deeply mistaken. In 2017, specialists in different parts of the world purchased 250 bottles of drinking water from 11 global brands. Their task was to study how safe bottled water is to drink. In 93% of the samples tested, scientists found microplastics. Moreover, it turned out that in bottled water, the amount of microplastics is almost 2 times higher than that recorded in tap water. In some samples, the amount of plastic reached 10,000 molecules per 1 liter of water. It is impossible to see these plastic particles with the naked eye, since their size for the most part does not exceed 100 microns, which is comparable to the diameter of a hair. Scientists have suggested that plastic containers may be the source of plastic in drinking water.

Fish

One food that also contains microplastics is marine fish. In addition, microplastics have been found in all types of marine organisms, from plankton to birds and mammals, in the same food chain.

Microscopic particles of plastic enter the fish with food and remain in its digestive system. In most cases, plastic in fish is not terrible for humans, since no one eats the insides of fish, although it harms the fish itself. But researchers have found that, in some cases, the plastic enters the fish's bloodstream, and thus into its meat. And such a product is no longer the safest for humans. Experts suggest that at least half of the world's population absorbs microscopic plastic fibers with food.

How microplastics affect human health

Today, experts have no scientific evidence that microplastics are dangerous to humans, since serious studies have not yet been conducted on this topic. However, many scientists suggest that the consumption of plastic, even in the form of microfibers, can lead to gastrointestinal disorders, tissue inflammation, liver problems, endocrine disorders, and even malignant cell transformation. Together with plastic, toxic chemicals and other pathogens can enter the human body. According to scientists, only the largest particles of microplastics enter the intestines, smaller ones can penetrate the bloodstream, lymphatic system, and even reach the liver.

In 2016, Dr. Una Lonnstedt, together with colleagues from Uppsala University (Sweden), studied the behavior and health status of perches kept in a reservoir contaminated with plastic. Scientists have found that 15% fewer fry hatch from eggs in a polluted environment than in a clean reservoir. In addition, the inhabitants of waters rich in microplastics grow smaller, they are slower and die faster. And most interestingly, the habitat affects the food preferences of fish. Residents of polluted water bodies, choosing between plankton and microplastics, often choose the latter. And although this study only concerns fish, scientists saw a threat to humans in its results.

How to protect yourself from microplastics

Cosmetics. The first thing that experts advise in this case is to follow the rules of prevention. First of all, limit the use of products containing microgranules. And these are some toothpastes, powders, cosmetics. By the way, some countries, such as Canada, the USA, Sweden, New Zealand, have already banned the import and sale of products containing plastic on their territory.

In cosmetics, plastics are most commonly found as:

  1. Acrylic polymers and copolymers. This is the largest group of synthetic polymers used in cosmetics. It is found in hair care products that fix the hairstyle or create an antistatic effect.
  2. Polyurethane. Contained in products that fix the hair.
  3. Polyesters. These are primarily pigments in decorative cosmetics, as well as substances with stabilizing, film-forming or softening properties.
  4. Polyamides. Contained in creams and cosmetic products that create a matting or shimmering effect.
  5. Polyquaternium-7. It is present in hair and skin care products designed to eliminate their drying.

Many of these components, according to the specifics of their action, have analogues among natural substances. For example, when choosing skin and hair care products, it is better to give preference to products that contain glycerol, fatty acids, fatty alcohols and amino acid esters. They, like plastic, prevent moisture loss, soften the skin, and stabilize cosmetic emulsions.

Clothes. If you can’t completely abandon things made of synthetic fibers, then at least you should learn how to wash them correctly. In order to get as little microplastic as possible into the environment, synthetic items must be washed on the shortest cycles, at low temperatures, using the lowest spin speeds. Also, instead of the usual laundry detergent, it is better to use liquid detergents. This is important, if only because during each wash of a product, for example, from fleece (treated with TPE), up to 250 thousand plastic microparticles enter the wastewater. Over time, they end up in drinking water.

Plastic waste. Third rule: Reduce plastic waste. This can be done if you refuse a plastic bag in favor of a paper bag, choose drinks not in plastic, but in glass containers.

The impact of plastic packaging on the human body

Scientists analyzed how different types of plastic packaging affect human health, and also studied under what circumstances such packaging " produce the maximum amount of microplastics and other harmful substances in food, which makes them truly dangerous.

Polyethylene terephthalate (PET)

Used for water and juice bottles. On the container, it is indicated by the symbol of a triangle of three arrows, inside which there is the number 1, and below the Latin abbreviation - PET.

Considered one of the safest plastics for food storage. But as studies have shown, when exposed to high temperatures, PET packaging releases a chemical element known as antimony in unsafe quantities. This process is enhanced if food in PET containers is heated in the microwave. Antimony poisoning causes nausea, vomiting and diarrhea.

High-density polyethylene

It is used in packaging for milk, juices, water, shampoos and detergents. The symbol is a triangle of arrows with the number 2 and the abbreviation HDPE.

The danger of such packaging is that when it comes into contact with heat (for example, under the influence of direct sun or hot liquid), substances are released from it into food, which cause the so-called estrogenic effect. These substances are associated with the risk of breast cancer, endometriosis, testicular cancer, precocious puberty, deformation of the genital tract, and deterioration of sperm quality.

Polyvinyl chloride

As a rule, meat, meat sandwiches, bath accessories, and also from this material are packed in containers with the designation PVC and a triangle with arrows and the number 3 make cheap plumbing.

The main danger of this material is that in contact with water it releases toxic phthalates, which in some European countries are already listed as high-risk substances. There is speculation that phthalates can cause hormonal imbalances, improper development of the reproductive organs, and other health problems.

Low density polyethylene

These packages have LDPE and a quad triangle. Shrink wraps, milk boxes, and take-away beverage containers are made from this material. Low density polyethylene packaging carries minimal health risks.

Polypropylene

Containers with the letters PP and a triangle with the number 5 inside, as a rule, are used for the production of cups for yoghurts and food containers. Like the previous version, this type of plastic is considered relatively safe for humans.

Polystyrene

Containers from it can be recognized by the symbols PS and a triangle with the number 6. This material is used for takeaway packaging, as well as in the fishing industry. Styrofoam cups for takeaway drinks and lids for them, juice bottles, disposable tableware and containers are made from it.

Studies show that polystyrene releases carcinogens when in contact with hot foods.

Other plastics

If the packaging has a triangle symbol with a 7 and the inscription OTHER, this means that none of the above types of plastic was used in the manufacture of containers in pure form. As a rule, it is a mixture of different plastics. Large bottles for water or juices are usually made from such material. Researchers have found that bisphenol A is often present in the mixture of plastics, which gives rigidity to the container. But it can also cause hormonal changes, reproductive problems, asthma, and obesity. However, scientists are most concerned about the fact that in many countries this material is still used in the production of baby bottles.

Protecting yourself from microplastics and their potential harm is not as difficult as it might seem at first glance. Experts advise drinking water from glass bottles and giving up straws, buying fish from trusted fish farms, using only natural cosmetics, giving up synthetic clothes, and replacing plastic bags with natural ones - paper or fabric.

Sources
  1. BBC News (Russian Service) – Plastic in bottled water: WHO launches investigation
  2. Science (Journal of the American Association for the Advancement of Science) – Environmentally relevant concentrations of microplastic particles influence larval fish ecology
  3. BBC News (Russian service) – Marine fish get used to eating plastic
  4. BBC News (Russian Service) – Seven graphs explaining why plastic in the ocean is bad