Copertina - Microplastiche

Microplastics: an invisible danger that travels across seas and rivers to our tables

Since the Second World War, the production and use of plastics have increased exponentially; in fact, plastic is a material that is of fundamental importance in our economy and simplifies everyday activities thanks to its lightness and low cost.

Plastic materials are found practically everywhere: in food wrappers and packaging, in the most varied beverage containers, in toys, in car components, in cosmetic containers and in cosmetics themselves. However, the omnipresence of plastic goes unnoticed, we don't notice it and we almost forget it. Since the 1960s, plastic production has increased by approximately 9% annually creating a $ 600 billion global industry.

According to a 2017 study published in the journal Environmental Science & Technology, about 320 million tons of plastic were produced in 2015 alone, most of it destined for single use and then disposed of rather than incinerated or recycled. But this plastic remains in the environment for centuries.

An estimated 8 million tons of plastic end up in the seas and oceans each year, releasing billions of microscopic particles that travel to ocean surface waters. The entry of many plastics into the oceans is favored by maritime operations but unfortunately the 80% of this material comes from terrestrial sources. The waste plastic thus arrives at the salt water in the form of garbage, drains and / or industrial waste through the currents of large rivers and streams, leaks (accidental or otherwise) of waste water or carried by the wind and tides.

The production and dispersion of waste are intrinsically correlated and proportionally associated with economic development, local infrastructure and relevant legislation. Today, uncollected and non-disposed waste accounts for around 75% of land discharges while the remaining 25% comes from waste management systems.

What are microplastics, how they are formed and where they are found

Recently, the discovery of microplastics (MP) has raised many concerns among scientists and researchers. MPs are defined as plastic particles with dimensions of less than 5.0 mm which, even if they are invisible (or almost invisible) to the naked eye, unlike plastic bottles abandoned on beaches around the world, constitute the 94% of approximately 1, 8 trillion (= 1.8 trillion!) Of plastic pieces that make up the "Plastic Patch" of the Pacific Ocean; MPs have also been found in all forms of marine life, from zooplankton to whales. The MPs also include those fragments> 1µm. This definition is in accordance with the US National Oceanic and Atmosheric Administration (NOAA).

The Plastic Patch or Great Pacific Plastic Patch, also known as the "Pacific Plastic Island", is the largest floating garbage area in the world located between California and Hawaii and containing plastic waste ranging from plastic tarpaulins to greenhouses and trucks, bottles and containers of various types, toys, electronic components waste, fishing nets, bags and much more.

This abnormal mass has reached 80,000 tons in weight and, according to a study published in March 2018 in the journal Scientific Reports, its area is approximately 1.6 million km2, 16 times larger than previously recorded through surveillance. air and naval, 4 times the size of California and 3 times the size of France. There are 6 other plastic islands: the South Pacific island, 8 times the size of Italy, the North Atlantic island of similar size, the "smaller" South Atlantic island of 1 million km2, and those of 'Indian Ocean and the Barents Sea of more recent formation and discovery.

The degree of degradation of the plastic depends on several factors such as: the type of polymer; the time it remains in the environment; environmental conditions with atmospheric agents; the temperature; the sun's rays and the pH and the slow degradation carried out by some microorganisms. Over time, MPs contaminate the marine ecosystem and consequently the food chain, including products intended for human consumption. Figures 1a and 1b compare the density (in Kg / Km2) of the 1962 plastic patch with that of 2018.

Currently, this form of pollution provides for the classification of MPs in primary and secondary. Primary MPs are plastics specifically manufactured by industry as components of many commonly used objects and / or products. An example are the microbeads and exfoliating granules, or "scrubbers" present in many cleansers and cosmetics for the face and body or in toothpastes that have replaced natural and non-polluting ingredients such as ground almonds, oatmeal, sugar, pumice .

These MPs are typically composed of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET) and nylon and, after use, are immediately flushed down the sewer system. Due to their small size, they are not retained by the various filters for the preliminary treatment of waste water and arrive in waterways and oceans.

Densità della microplastiche negli oceani nel 1962

Density of microplastics in the oceans in 1962

Densità della microplastiche negli oceani nel 2018

Density of microplastics in the oceans in 2018


Wastewater treatment plants remove between 95-99.9% of microspheres by allowing an average of about 7 microspheres to pass per liter of discharged water. It seems a negligible number but a treatment plant discharges about 160 trillion liters of water per day, resulting in a daily release of about 8 trillion of microspheres into waterways.

Each household contributes to the release of about 808 billion granules in a single day due to the cosmetic exfoliation and cleansing of the person. Many companies are striving to gradually eliminate microspheres from their products, favoring a return to scrubs of natural origin, but several studies have found that there are still at least 80 different facial products on the market containing primary MP among the main components.

However, these data do not take into account the sewage sludge which is reused as fertilizer after the treatment of waste water containing microplastics which will thus be diffused into the soil. Some primary acrylic, melamine or polyester MPs are produced to sandblast engines and hulls of boats to remove old paint, rust or scale.

In this case, these MPs become more dangerous as they are repeatedly used until they reduce excessively, losing their abrasive capacity and over time they collect and incorporate heavy metals such as cadmium, lead and chromium which cause severe intoxication (and some of them are carcinogenic). Secondary MPs, on the other hand, enter and spread in the environment, both at sea and on land, through the fragmentation and degradation of larger objects or pieces of plastic following exposure to UV light, freezing, wind, wave motion and abrasion. given by the waves and sea water.

Over time, secondary MPs can further reduce down to a few micrometers: the smallest particle currently detected is in fact 1.5 µm. Another non-negligible source of secondary MP pollution derives from the breakdown of synthetic fibers, such as fleece, polyester, nylon and acrylics, which can be eliminated from clothing and dispersed into the environment through the wastewater of domestic and industrial washing machines at the end. of each wash.

Each item in a laundry load can lose up to 1900 MP fibers, although washing machine filters are capable of retaining a certain amount. In fact, a study conducted by the University of Paris East and published in 2016 in the journal Marine Pollution Bulletin, showed that every year between 3 and 10 tons of synthetic fibers alone end up in the city air. In the city air are also added the MPs that are formed from styrene-butanediene dust due to tire wear and end up in drains and waterways up to the seas.

Every 100km traveled, cars and trucks release more than 20g of MP each with an estimated annual emission per vehicle between 0.23-4.7kg. Fishing, recreational and commercial activities, maritime transport and industries on marine platforms also contribute to the release of large quantities of plastic into the sea, severely damaging the marine ecosystem.

Fishing gear, discarded or lost, such as monofilament plastic lines and nylon nets, float and oscillate at varying depths constituting deadly traps for all marine organisms. In March 2013, the discovery of a 10-meter dead whale on the Spanish beaches between the province of Almeria and Granada caused a sensation, even if it is not the only case of this type of news: every year more than 1 million birds and about 100,000 marine mammals die from plastic waste that travels to the oceans.

According to the necropsy performed by veterinarians, the death was caused by severe intestinal failure caused by the ingestion of almost 20 kg of plastic found in the animal's stomach. This waste was analyzed and, in addition to plastic fragments of various sizes (including MPs), plastic tarpaulins bearing their origin were found: the greenhouses of Almeria, also better known as "Mar de Plastico" , the black heart of Europe.

These agricultural greenhouses, also visible from space, extend along the Andalusian coasts covering, in a uniform and iridescent way, an area of over 26,000 hectares. Since 1980, most of the fruit and vegetables that arrive on tables throughout Europe have been intensively produced in these greenhouses, with a turnover of 1.5 billion / year. Organic and integrated cultivation has also recently emerged to meet the demands of consumers. The Mar de Plastico initially raised the economy of the area but the consequences were disastrous: not only the land was exploited causing a real ecocide, but also people, migrants who, coming to Europe, found hell here.

A scandalous situation, repeatedly denounced by both Spanish and foreign newspapers and media (including an episode of Report and Direct Presa in 2018): workers do not have a stable contract, nor guarantees and insurance and health coverage, underpaid and forced to work inside greenhouses where the temperature can even reach 45 ° C.

To worsen this picture, there is the problem of plastic which has incorporated pesticides and products used for the treatment of plants: in fact, a strong hot wind often rises and tears the sheets and carries them towards the sea; once they arrive in the water they travel for years carried by the currents, becoming a trap for marine organisms and slowly forming MPs that spread more widely and, above all, invisible. Figure 2 shows the impressive expanse of the Mar de Plastico.

Today the Mediterranean Sea, the Mare Nostrum dear to the ancient Romans, is literally becoming a sea of plastic in which about 700 tons of waste arrive every day, of which the MPs are the problem, paradoxically, more "big" precisely because of their reduced dimensions and therefore of their ubiquity. In some places, the concentration of MP is even the highest in the world precisely because the Mediterranean is a closed sea and each particle could have a residence time of almost a thousand years. Another problem is represented by the fact that 2 very polluted rivers flow into it, the Po and the Danube.

Integration of MPs in marine organisms and in the food chain

A 2016 United Nations (UN) report documented more than 800 animal species contaminated with plastic through ingestion, respiration or entrapment: of these 800, 220 species ingested large amounts of naturally occurring MP.

The ingestion of MP particles has been found in all species of marine organisms: mammals, fish, molluscs and annelids, crustaceans, invertebrates and fish-eating birds. PD are mainly concentrated in the digestive tract and remain there for a long time, sometimes even for the entire life cycle of the animal where, once degraded into even smaller fragments, they move into the circulatory system and surrounding tissues.

For the consumption of large fish or crustaceans, the elimination of the entrails contributes to the reduction of MP consumed while in small animals the digestive system is often not removed, constituting a danger for the final consumers. In many annelids (marine worms), crabs and sea cucumbers, more than 520 microplastic particles of PVC (Poly Vinyl Chloride) and nylon thread, high and low density polyethylene (HDPE and LDPE respectively) and PP were found per organism analyzed. .

These substances are commonly found in plastic bags, food containers, bottle caps, and various wrappers, tarps and canisters. MPs have also been found in corals, the main constituents of the wonderful coral reef: MP adheres to the coral structure, preventing normal filtration activity and causing their bleaching and consequent mortality. The zooplankton also ingests MP and excretes feces contaminated by them; the zooplankton voluntarily ingests the MPs as these particles emit substances very similar to the phytoplankton that the zooplankton feeds on.

MPs also attach to the appendages and exoskeleton of these organisms. In an animal, digestion takes a maximum of 2 days while it takes about 14 days to eliminate MP; however, if the MPs become entangled in the gills they are not completely eliminated. When an animal that has ingested MP is eaten by its predator, the MPs are incorporated into this higher level of the food chain.

For example, the researchers recorded high amounts of MP in small lanternfish which are among the main prey of valuable fish such as tuna and swordfish. The MP, due to their conformation and chemical structure of the components, are able to absorb pollutants and chemicals that are transferred to the tissues of organisms. Finally, the ingestion of plastic and MP endangers the life of marine organisms due to the false feeling of satiety, resulting in a reduction in the intake of food and nutrients, in addition to the physical damage caused by these materials.

Freshwater fish also do not save themselves from MP; a study conducted on the Argentine coast, along the Rio de la Plata estuary, found the presence of MP in the bowels of 11 species of fish with 4 different eating habits: detritivores (i.e. they feed on organic substances that settle on the seabed, known as scavenger fish), planktivores (they feed on plankton), omnivores (like us humans, they feed on a wide variety of foods) and ichthyophages (they feed on other fish).

 The plastic we eat and the impact on our health

Fish is a significant source of protein for humans. As of 2015, global fish intake accounted for nearly 7% of all protein consumed and approximately 17% of animal protein consumption. The global consumption of mussels (shellfish) per capita exceeds 20 kg / year.

World trade in fish products in 2016 alone amounted to almost 133 billion $ with over 90% of products imported from geographic areas with high amounts of plastic waste. MPs ingested by marine organisms can therefore arrive on our tables, at the end of the food chain. The State University of New York conducted a study in which it sampled 18 species of fish - all of which showed elevated levels of MP in their systems.

These plastic fibers, while in water, are chemically associated with metals, polychlorinated biphenyls and other toxic substances (insecticides, pesticides, herbicides…). The MP-metal-pollutant complex can therefore enter our body through the diet, posing an emerging problem in terms of food safety. A plastic particle of 150 µm (0.15mm) can enter our body without problems and, from the gastrointestinal tract can reach the circulatory and lymphatic systems and accumulate in secondary organs such as lungs, liver, gall bladder.

Not many studies have been conducted so far as people cannot be asked to ingest microplastics voluntarily but researchers have observed that MP plasticizers cause growth abnormalities, endocrine system interference and reproductive problems in laboratory animals: these effects are associated with exposure to phthalates, used to give plastic greater flexibility and moldability.

Another substance widely found in MP is Bisphenol A (BPA), produced and used since the 1960s in the production of polycarbonate plastics to impart transparency, thermal and mechanical resistance. It is found in food-grade containers and in the resins that make up the internal protective coating in food and beverage cans. BPA has been recognized as an endocrine disruptor, that is, it is able to alter the hormonal balance, especially during the intrauterine development phases and in early childhood, creating long-term damage to the reproductive, nervous and immune systems. This evidence was recognized in 2014 and 2017 by the European Chemicals Ahency (ECHA) chemicals agency.

The increased risk of obesity and breast cancer are other particularly worrying effects as the population is constantly exposed to BPA, also demonstrated in Italy by the Istituto Superiore di Sanità (ISS), as part of the PREVIENI project on biomonitoring of endocrine disruptors.

In fact, BPA can pass in small quantities from the containers that contain it to food and drinks, especially at high temperatures. Since 2009, BPA has been included in the list of prohibited substances in cosmetics (EC Regulation 1223/2009) and, in 2011, in the manufacture of baby bottles (EU Regulation 321/2011). In addition, in 2015 the European Food Safety Agency (EFSA) published a very detailed assessment of exposure to BPA.

Another dangerous component of MP is Tetrabromobisphenol A (TBBPA), a flame retardant derived from BPA and used to increase the thermal resistance of plastics. TDBBPA has been shown to interfere with the normal activity of thyroid, pituitary and reproductive system hormones. Other substances added to PD are linked to potential harmful health effects such as coloring agents which often contain heavy metals. PD can also collect pathogenic and polluting microorganisms from the air, water and soil and, through ingestion, cause infections of the respiratory and gastrointestinal tract, especially in people with a weak immune system.

However, MP is not found only in fish, molluscs and crustaceans but also in cooking salt. Researchers at the University of Shanghai conducted large-scale research to be able to analyze multiple salt samples from different geographic areas.

The study, published in 2015 in the journal Scientific Reports, analyzed samples of sea, mine and lake salt of different brands: out of 36 samples analyzed, 90% is contaminated by microplastic consisting of PE, PP and PET, the most commonly used plastic. to produce disposable packaging and disposable cutlery. Samples from Asia recorded the highest average contamination levels, with over 13,000 MP particles in a single sample from Indonesia.

In fact, Asia is the continent that suffers most from MP pollution, with its 54,720 km of coastline. The salts of 21 countries of Europe, North and South America, Africa and Asia were analyzed and the products that did not contain MP are 3 and come from Taiwan (refined sea salt), China (refined coarse salt) and France (unrefined sea salt obtained with solar evaporation). The other two types of salt, salt lake and mine, contain less MP.

In conclusion, considering the average daily intake between 5 and 10 grams, an adult could ingest, with the sole consumption of salt, up to 2,000 fragments of MP per year. A 2015 German study published in the Polish Journal of Food and Nutrition Sciences, showed that honey is also contaminated by MP with an average of about 200 particles per kg: these are fragments of synthetic textile fibers, fragments of degraded waste and granules cosmetics and industrial; these substances may have been carried by bees or deposited on the flowers.

In 2014, the same German researchers (Food Additives & Contaminants: Part A magazine) observed that beer also turned out to be polluted by MP. In fact, fibers (2-79 / liter), fragments (12-109 / liter) and granules (2-66 / liter) of plastic were found on all 24 beers analyzed. How the contamination occurred is not known: scholars have hypothesized a malfunction of the machinery, dirty bottles or contamination of barley and hops.

Other studies have also shown the presence of MP in mineral water in reusable PET plastic bottles: these MP come from the packaging and, with each use, from 2 to 241 plastic particles are taken per liter. Not even tap water is saved. In fact, in 2017 a survey was conducted by the non-profit journalistic organization Orb Media with the collaboration of the State University of New York and the University of Minnesota on domestic tap water from around the world, testing 159 samples of drinking water. of large and small cities.

The sample 83% contains MP fibers. As mentioned in the first paragraph, many MPs also come from the air which, traveling without barriers, can contaminate water sources. Another source of contamination of tap water are some pipes made of plastic materials, together with the inefficiency of the filtering systems that are unable to retain the MPs.

However, bottled water contains about twice the MP per liter of tap water. The news of the discovery, for the first time, of MP in the faeces of more than 50% of humans in the world dates back to October 2018, a frightening estimate. The study, awaiting publication and presented on 23/10/2018 at the European Congress of Gastroenterology in Vienna, was conducted by researchers from the University of Vienna in collaboration with the Austrian environmental agency. The MP particles found in the intestines of study participants vary in size from 5-500µm and could therefore enter the bloodstream and reach organs such as the liver. Among the materials identified the PET of plastic bottles and disposable packaging.

What steps have been taken and what can we do

With the growing awareness of the negative impact of PD on the environment and on humans, several groups around the world have funded campaigns for the removal of PD from various everyday products. Among these, the “Beat the Microbeads” campaign which aims to promote the removal of scrubbers and granules in cosmetic products.

The Adventurers ans Scientists for Conservation is a non-profit organization from Montana (USA) that manages the Global Microplastics Initiative, a project that deals with the collection of water samples to provide scientists with increasingly numerous and accurate data on the dispersion of MP in the environment. UNESCO (United Nations Organization for Education, Science and Culture) has also sponsored several research projects on the transboundary problem of MP pollution. In the US, Illinois is the first US state to ban MPs in cosmetics while in 2015 President Obama signed the “Microbeads Free Waters Act, which came into force in July 2017, which bans exfoliating products and their rinsing.

However, this ban is not extended to household products. Also in July 2018, the U.S. House of Representatives passed an MP reduction amendment to combat marine, land, and great lake pollution and increase monitoring testing, cleanup and education. The current President Trump has signed the reactivation of this proposal. The Japanese government, on a proposal from the Ministry of the Environment in June 2018, also approved for the first time a bill to reduce the production of MP by increasing public education and awareness on the correct recycling of waste.

A number of recommendations have been published on methods to monitor the amount of MP in the oceans but no sanctions are specified for industries that continue to produce products with MP. The United Kingdom in 2017 approved the "Environmental Protection Microbeads Regulation" which prohibits the production of any product containing microbeads and exfoliants, with specific penalties for offenders.

Finally, in 2015 the European Parliament voted in favor of a restriction on the use of plastic bags and, in September 2018, MEPs approved a maneuver against plastics to increase their recycling in the EU. It was also called for the implementation across Europe of the ban on adding MPs to cosmetic products and detergents by 2020 and the adoption of measures to minimize the release of MP from fabrics, tires, paints and other materials. pollutants. In October, parliament approved a Europe-wide ban on the use of certain disposable plastic products found in abundance in the seas and for which non-plastic alternatives are already available.

By 2019, therefore, we will say goodbye to straws, plates, cutlery and plastic cotton buds that will be replaced by products made of sustainable materials. As for packaging and other containers, manufacturers will have to limit production and new labeling with more precise disposal instructions will be required. All products based on oxy-degradable plastics have also been banned, i.e. common plastics which tend to break easily into small fragments and which, due to the additives contained in them, are not compostable or degradable.

As for the actions of us citizens, avoiding MPs is now almost impossible since they are ubiquitous but, it is essential that everyone respects the rules, others and above all the environment to improve everyone's life. Starting with large plastic, first of all it is absolutely forbidden to leave any type of waste on the ground: there are special bins and they are everywhere. In the absence of them you can always put the garbage in a bag and throw it as soon as possible. If you notice misconduct by another citizen, point it out to him.

Collect rubbish left on the ground even if it is not yours: the land belongs to everyone. Avoid, if possible, the consumption of ready-to-eat foods in disposable packs or trays and prefer those in paper, cardboard or tetra-pack packaging. When you go to a party, don't throw balloons into the sky. Respect separate collection and, if in doubt, read the instructions on the label.

Do not leave the waste lying around if you do not know where to put it or if the bins are full, otherwise you will complain about the rats in the city and the fault is not the mice. As for MP, limit the consumption of fish products such as tuna, swordfish and shellfish: do not eliminate them because they have many benefits on our health. Buy quality fish products from trusted fishermen or vendors and ask for the entrails to be removed if necessary.

When you go shopping, always carry your reusable bags with you. Avoid using plastic cutlery and cups and prefer paper or wooden ones; at the end of the day, always take care to dispose of them correctly. Bring your ceramic mug to work so you can avoid using a new plastic cup every time. Always carry your water bottle (perhaps BPA-free if made of plastic) instead of buying bottled water.

When cooking foods, wait for them to cool before transferring them to plastic containers to avoid MP release in high temperatures. Do not buy scrubs or exfoliants unless they are natural and avoid glitter-based products as, even if they are effective, they are made of PE or PET and are easily dispersed, as well as being inhaled. Whenever possible, use public transport, especially rail, or bike and always check that the tire pressure of your car is at the right levels.

Buy fewer synthetic clothes or, in case, you can put a filter in the washing machine that captures the synthetic fibers; alternatively, put them in a specific filter bag for washing machines and, as regards the dryer, always take care to clean the filters to eliminate the fluff that forms. If we don't respect the environment, we don't respect ourselves and we pay the consequences.

Every plastic we make, use and eventually abandon, intentionally and unintentionally, eventually comes back to us in an invisible and uncontrollable way, harming the environment and harming ourselves. We still have time to save our planet and a few simple gestures in our daily life are enough to do so.



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