Massive use of polymer compounds started in the 50s and has been growing ever since. Even the most responsible consumer is unable to completely remove plastic from their lives. But the biggest concern for doctors and scientists is the plastic we eat without knowing it, and the plastic we eat from. To figure out how safe it is, you have to start from the very beginning.
Text: Marina Levicheva
Plastic and microplastics, flora and fauna
It hasn't been long since marine biologist Ed Carpenter noticed strange white specks in the Sargasso Sea in 1971. But it was enough to make sure that plastic in the oceans is not just a problem, but a real environmental disaster. It affects marine systems by altering the rate of growth, metabolism and physiology of flora and fauna. According to the latest estimates, between 4.8 and 12.7 million tons of plastic end up in the ocean each year, and the numbers could double by 2025. But plastic - including with water - also gets into the soil, which endangers the crops that grow on it and the animals that feed here.
Scientists started talking back in the 1990s that up to 80% of the plastic found in the ocean is not biodegradable. However, the term "microplastic" to refer to plastic particles no larger than 5 millimeters in size was introduced by the marine biologist Richard Thompson only in 2004. Research data turned out to be more and more frightening, but public consciousness was in no hurry to change.
A notable shift came when Greenpeace released information on the dangers of microbeads in cosmetics (cleansers, exfoliators, shower gels) for marine life. A 2016 petition to ban the use of microbeads in the UK garnered 365,000 signatures in just four months, making it the largest environmental petition in the world. At the same time, animals absorb plastic in critical quantities, which leads to the death of even the largest of them, as happened with a whale in Thailand.
What is plastic and what you need to know about its toxicity
“In fact, plastic is a whole group of materials: polyethylene, which can be synthesized at various densities of carbon atoms, thermal conditions (products marked PET, LDPE, HDPE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC) and other types of plastics (polycarbonate, polyamide) marked with O or OTHER,”says Vitaly Khoroshavin, director of the Institute of Earth Sciences at Tyumen State University.
And no, not all plastic is toxic. “Polymers become toxic under different conditions: some cannot be heated, others cannot be washed, others come into contact with food as a result of improper storage, and so on. The plastic itself is not toxic, it is made dangerous by the substances that are added here for strength,”explains Tamara Gelashvili, endocrinologist at the Medintsentr Clinical Diagnostic Center.
Some types of plastics begin to disintegrate into separate components in contact with alcohol. If you've ever poured strong alcohol into a plastic cup designed for water - for example, whiskey from a duty-free shop on an airplane - you've probably smelled that characteristic pungent smell. It appears when a volatile plastic monomer is released.
Why is everyone so afraid of bisphenol A
“In 95% of cases, the inexpensive bisphenol A (BPA) hardener is used to complete the curing process and convert the free-flowing plastic material to the desired shape. It was synthesized in 1891 in the laboratory of Russian chemist Alexander Danilin and is the end product of the reaction of phenol and acetone under the influence of hydrochloric acid, says nutritionist Olga Gulenkova. - In small concentrations, bisphenol A is not harmful and in 2010 it was recognized as safe by the Russian representative office of the WHO. However, in large quantities, as well as when heated and interacted with certain substances such as alcohols, oils, acids and other free esters, it can be dangerous."
5 quick facts about plastic
40% plastic - packaging that is used only once;
44% of the plastic ever created is manufactured after 2000;
29% of all plastic is produced in China;
In Europe, 30% of plastic is recycled - this is the highest level in the world;
600 billion plastic bags are produced annually.
How to choose the right dishes and packaging
“To distinguish food-grade plastic from non-food plastic, it is enough to look for the food-grade plastic icon on it when buying any plastic tableware - images of a glass and a fork. And on the plastic packaging you should look for the BPA-free badge - it does not contain bisphenol A,”advises Sergey Sysoev, head of the department of independent environmental review of Ecostandard Group.
How much plastic do we eat and why is it a problem
Scientists have found that every year we consume more than 70 thousand pieces of microplastics that enter food through packaging, industrial waste and food chains. The analysis of the results of 26 studies on the topic, which studied the content of microplastics in seafood, salt, sugar, honey, beer and water, made it possible to speak only about 39-52 thousand particles, but taking into account the amount of plastic that we inhale (there is even more of it in the air, than in shellfish), gave a more menacing figure. And by the way, according to the same study, another 90 thousand pieces of microplastics enter the human body from drinking water per year.
Scientists are still debating how dangerous plastic is to humans. The main problem is that it can potentially bind to hormones, interfering with important processes in the body. In marine animals, for example, bisphenol A does this in several ways: by mimicking estrogens, by blocking the work of other sex hormones or thyroid hormones. By the way, BPS, which is often used as an alternative to BPA, does the same. Simply replacing BPA with BPS gives the manufacturer the right to say their product is BPA-free.
Harvard scientists have also proven the effect of bisphenol on the eggs of rhesus monkeys. Some phthalates, according to a 2008 study, can cause inflammation in mice, and male rats fed phthalates have developed dysfunctional sperm. However, the results of animal studies can not always be generalized to humans. Even the authors of the most high-profile works note that very high doses of substances are used in experiments, and the effects will not necessarily be similar (although it is impossible to verify this for ethical reasons).
Reviews of the literature on the effects of plastics on human health have suggested a link between exposure to BPA, phthalates and plastic constituents and decreased fertility, impaired immune function, diabetes mellitus, and cardiovascular disease. But here it is important to understand that all studies were epidemiological, so this relationship is not necessarily causal.
Scientists separately note that in the future it is important to focus on the cumulative effects of chemicals in plastic on the body. While the constituents of plastics are being studied separately today, PVC, as an example, used in a wide range of household products, may contain BPA, phthalates, flame retardants, lead and cadmium. And how all this together affects a person, so far one can only guess.
Should I transfer food from a plastic container to a plate?
“It is advisable to transfer food to ordinary dishes if you reheat food in the microwave, because when heated, various volatile organic compounds are released, mainly polyvinyl chloride (polyvinyl chloride itself is safe for humans, unlike its combustion products. - Approx. ed.). For heating, you can use only thermostatic plastic (there should be a corresponding icon on it), but even in this case, the heating should not exceed 60 degrees,”says Sergei Sysoev.Note that even if the plastic, when heated, emits substances that are safe for humans, the container itself gradually collapses - its surface may become rough or get microcracks, where food debris and microbes will accumulate. And water, according to Tamara Gelashvili, is better to take with you in plastic, which is not exposed to sunlight and is intended for storage and reuse.
What governments and laboratories are doing
Canada, the EU, and some US states have banned the use of BPA in certain product categories, including baby food packaging, toys, and baby care products. Even so, there remains a problem with "Generally Recognized Safe" substances (GRAS) - they are, for example, used in packaging for products such as sugar or coffee, with a long and risk-free history of use. More and more experts think that this category of substances has problems with control and evidence base.
In March 2018, after the journalistic organization Orb Media discovered plastic particles in bottled water of several major brands, the WHO took a close look at the health impact of microplastics. “Plastic is not processed in the body, so it is constantly circulating. The only question is how quickly the concentration of microplastics in food and air will reach the level at which changes in human health indicators will be statistically significant,”says Larisa Prikhodko, business development manager at Bumrungrad International Hospital in Bangkok. By the way, on the island of Samet in the Gulf of Thailand, it is already forbidden to use plastic bags and polystyrene containers. And this, apparently, is only the beginning.
But scientists are also not innocent when it comes to plastic waste. In 2014, laboratories around the world produced about 5.5 tons of plastic - almost 2% of the total waste. And while laboratory experiments cannot be compared to using disposable cups, researchers are trying to come up with something. For example, biologist Nidi Sharma from Stanford University began growing several plants in a single plastic pot and reusing plastic tags by washing them in ethanol (she talks about these and other life hacks not only to students, but also on the Bitesize Bio website). And other laboratories use glassware instead of plastic, including volumetric pipettes and Petri dishes. Yes, they require careful sterilization after experimentation, but the effort is worth it.
Scientists think that a more responsible approach from plastics and food manufacturers could work, too: if plastic becomes easy to recycle, it will be recycled. And they cite the example of colored plastic bottles, the processing of which is five times more expensive than transparent ones: the pigment is quite difficult to remove, and the tinting of the plastic does not serve any purpose, except for advertising.
What to do for an individual person
In the modern world, contact with plastic is inevitable, but it is still worth trying to reduce its use. The simplest steps are to buy a glass water bottle and a reusable metal straw instead of disposable ones, and also not to use plastic packaging when not necessary (for example, many fruits have their own natural packaging). All this may seem like something insignificant, but environmentalists and eco-activists constantly say that the more people take such small steps, the better.
“You shouldn't use plastic with a pungent unpleasant odor - it means that low-quality raw materials were used in the production,” advises Tamara Gelashvili. - You can also limit the consumption of plastic, replacing it with more natural materials: store food in glass or ceramic dishes, when buying food, remove the packaging film from them,buy baby food in glass or cardboard packaging and so on."
“It is better to buy toys from well-known manufacturers who adhere to quality certification,” adds Sergei Sysoev. - A child's body is more sensitive than an adult, and even small concentrations of harmful substances can harm it. At the same time, children pull toys into their mouths, sleep with them and bathe in hot water, so it is important to monitor their quality."
Types of plastic and their properties
Different types of plastic are marked with a code of numbers placed in a triangle. The safest categories for food and drink are categories 1, 2, 4 and 5
01-PET (PETE) - polyethylene terephthalate - used in the production of disposable bottles for water and soft drinks, disposable plastic packaging, blisters. Suitable for single use; when repeated, it is possible to release phthalates, potentially associated with disturbances in the work of the nervous and cardiovascular systems.
02- HDP (HDPE2) - high-pressure polyethylene - opaque plastic bottles for juice and dairy products, containers for household chemicals, packaging of food products and motor oils are made from it. This is the most environmentally friendly and safest option.
03- PVC (V) - polyvinyl chloride - used in the production of pipes, floor and wall coverings, bathroom curtains, plastic bags, some toys. It can emit vinyl chloride and phthalates, is practically not recyclable, and when it is burned, it releases into the environment dioxins. They are toxic to various body systems, and under chronic exposure they caused various cancers in animals. Today, it is believed that absolutely every person has a background effect of dioxins on the body and it does not pose a danger - according to the WHO, the risk is increased in workers of certain industries, and in some regions also in people who eat a lot of fish.
04- PELD (LDPE) - low pressure polyethylene - used mainly for the production of bags, cling film, garbage bags. This plastic is not resistant to temperatures, and its integrity can be compromised even when exposed to direct sunlight.
05- PP - polypropylene - widely used in the production of food containers, syringes, buckets, yogurt cups, toys, baby feeding bottles. It can be heated up to 100 degrees.
06- PS - polystyrene - used for the production of food containers, packaging, cutlery, dishes, thermal insulation materials. Do not heat or store alcoholic beverages in it, as it can be released styrene, which was recently reclassified from possibly carcinogenic to likely carcinogenic to humans. The risk of complications is again high for those who work in the plastic industry..
07- PC (polycarbonate) and others - with frequent washing or heating may release bisphenol A.
Can plastic bottles be reused?
In 2015, the European Food Safety Agency concluded that at current exposure levels, bisphenol A poses no danger to humans, including unborn children. In addition, the microplastics found in bottled water are mostly polypropylene, which is considered safe for humans (although there is ongoing debate here).
Manufacturers recommend washing the bottle with warm water and soap after each use to get rid of bacteria, and also avoid using cracked or damaged bottles where insidious bacteria can settle.
Eco-friendly plastics and alternative solutions
Plastics are inexpensive, lightweight, durable, corrosion-resistant materials with high thermal and electrical insulating properties. And for this very reason they are actively used in various fields.Moreover, plastics have the potential to be used in the future for medical purposes and in the production of renewable energy, so no one is likely to completely abandon them.
Many manufacturers are now switching to bioplastics (for example, Lego, which does not make non-plastic products at all, has already introduced sugarcane plastics into its range) because sustainability is a good marketing ploy. But in reality, eco-friendly plastic may not be that eco-friendly.
For example, a bottle made from polymerized lactic acid (PLA) is difficult to compost and, if mistakenly placed in the PET group, could contaminate the entire cycle. In addition, the label “bio” on the packaging encourages people to consume mindlessly, which is contrary to the idea itself. Finally, plant-based plastic is getting the same criticism as biofuels - as the area where crops can be grown for food will decrease if the entire world switches to ecoplastic.
Innovation versus plastic
In fact, there is even plastic in tea bags. As of 2018, 95% of them have a seal at the very top, where the plastic is contained. The easiest and most obvious way to get rid of plastic problems in the future is to stop using it. But although there are active discussions about banning single-use plastic products throughout Europe, one cannot expect that all countries will pass the relevant laws at once. And even if so, there will be countries outside the EU, where something needs to be done too.
Scientists around the world are trying to come up with simpler ways to recycle plastic. People produce and use a million bottles per minute, of which less than half are recycled. But on a small island near Panama, the problem is being tackled by using bottles to build houses. Canadian Robert Bezout, who came up with the idea of turning plastic into buildings, admits that the idea came to him after he got tired of collecting bottles on the beaches of the island. The village, by the way, is now called Plastic Bottle Village.
Another innovation is the processing of plastics into oil. About 8% of the world's oil production is used for the production of plastics, and by 2050, the figure is projected to rise to 20%. Perhaps the best way to recycle plastic is to turn it back into oil for reuse. And Japanese scientists have already made a device that is capable of this. The process is surprisingly efficient - it allows you to get a liter of oil from a kilogram of plastic for as little as 20 cents.
ReDeTec has developed the first and so far the only system that can recycle plastic waste into new filament, and then use it for 3D printing. At the same time, various plastics can be loaded into the ProtoCycler printer - from defective 3D models to empty bottles.
Biodegradable packaging options are also emerging. The drinking water bottle, created by Icelandic designer Ari Jonsson, contains red algae powder and water. The mycelium of fungi has also found great potential. Experiments continue, but it is already clear that such packaging will have natural fire resistance and ductility.
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