Introduction

It is consumption that is the flywheel of modern society in the 21st century. It determines the economy and economic growth, and also becomes an existential value. At a time of overuse of plastic products in our market as they are relatively cheap and convenient to use, special attention should be paid to building public awareness of the harmful consumer behaviour associated with our purchasing choices. If we want to make sure we are buying microplastic-free products, we can check the composition of the product carefully on the packaging, verify the contents, and choose glass packaging over plastic, especially for food, and dutifully educate others about the harmful effects of microplastic particles on our health. Even taking your own bags for shopping, or buying food by weight rather than packed and on plastic trays, can reduce this pressing global problem of polymer waste pollution every day.

The improvement of the selective collection of plastics, accurate automated sorting, as well as reuse and recycling seem to be most significant in an era of plastic overuse. Waste sorting should be taught at primary school level, which seems to have been introduced from the earliest school years.

According to global researchers of the microplastic problem, it is important to make the public aware of the impact of plastics on human health, i.e. the educational role of science, but also the development of research on the topic. More lectures or surveys are needed on the disastrous effects of plastics on our lives. In addition, many research studies aim to improve measurement methods to determine what risks these microparticles pose to humans (Veerasingam et al., 2021).

The ubiquity of microplastics – a macro-level problem

In our time, microplastics are not subject to uniform definitions. According to EFSA (European Food Safety Authority), microplastics (MP)are a heterogeneous mixture of materials with different shapes. They can be in the form of fibres, flakes, ellipsoids or granules, with fragments ranging in size from 0.1 –µm to 5 mm still classified asmicroplastics. Those particles that are smaller in diameter, i.e. less than 100 nm, fall under the group of nanoplastics (EFSA, 2016). Microplastics can be divided into secondary microplastics, i.e. those that result from the degradation and fragmentation of polymeric plastics (Waller et al., 2017), and primary microplastics, i.e. those derived from chemical products often used in our homes such as cosmetics, laundry detergents, as well as pharmaceuticals and substances resulting from industrial processing. Their addition can often improve in the stability, density or abrasive properties of the materials in which they are used. They are also known to function as carriers of fragrances, moisturisers or other ingredients with an activating effect. Their fragmentation into smaller particles can be a consequence of the use of various synthetic materials from our surroundings, such as abrasion from tyres, clothes, shoes or furniture. It can also be the result of mechanical erosion (e.g.: due to wind and wave power) and abrasion of larger plastics by masses of sand and gravel or degradation due to ageing of the polymer material. The most common reasons for this phenomenon are various atmospheric conditions, such as high temperatures or UV radiation (Andrady, 2011).

Polymer microparticles can also be released during the production of plastic objects in industrial processes. Microbeads of plastic are generated every day in our homes, for example as a result of the use of cosmetics an d household chemicals, or the use of plastic crockery and packaging, and even from wearing clothes and items made of polymeric materials. Such particles then pass through the sewerage system. The particles flow through the sewerage system with the sewage, into watercourses and further into rivers and lakes, and contaminate the larger water bodies of the seas and oceans (Issac and Kandasubramanian, 2021). It turns out that microplastics are everywhere in our environment now, including oceans, rivers, sediments, sewage, soil and even exist as particles commonly suspended in the air (Rillig, 2012, Prata, 2018, Gasperi et al., 2018, Rios Mendoza et al., 2018, Alimba and Faggio, 2019, Ferreira et al., 2019, Koelmans et al., 2019).

Along with microplastics, other small molecules called auxiliary molecules (also present in plastics) such as plasticising, colouring or modifying agents, can be released into the environment. Their low molecular weight increases their susceptibility to migration into the environment; the rate at which they migrate also depends on the rate of ageing of the starting material and the prevailing atmospheric conditions in the environment. Substances introduced into polymer plastics, such as phthalates and dyes containing lead or cadmium, are identified as the most hazardous contaminants (Castle, 2007, WHO, 2019). Production of all plastics is growing at an alarming rate. Its growth is estimated to be sizable with each passing year: from 1.5 million tonnes in the 1950s to a projected 33 billion tonnes in 2050 (Rochman et al., 2013, Li et al., 2016). In particular, plastics are derived from synthetic polymers produced by polymerising multiple monomers and mixtures of different materials (Thompson et al., 2009). As a result, plastics are mainly produced as polyethylene (PE) or low-density polyethylene (LDPE) and high-density polyethylene (HDPE). A number of other polymers can also be mentioned, which include the popularly used ones: polyester (PES), polyethylene terephthalate (PET), polyetherimide (PEI, trade name: Ultem), polystyrene (PS), polypropylene (PP), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC, trade name: Saran), polycarbonate (PC), polycarbonate/ acrylonitrile-butadiene-styrene (PC/ABS), high impact polystyrene (HIPS), polyamides (PA, nylon), acrylonitrile-butadiene-styrene (ABS), polyurethanes (PU), urea-formaldehyde (UF), melamineformaldehyde (MF), polymethylmethacrylate (PMMA), polytetrafluoroethylene (PTFE) and polylactic acid (PLA), etc. All the polymers mentioned can have many applications in everyday life. For example, PP is widely used in: plant pots, bags, industrial fibres, nets, medical masks, bottle caps, rope, straws, containers, tanks and jugs, car fenders, plastic pressure pipe systems and centrifuge tubes. LDPE is typically used in outdoor furniture, wire cables, floor tiles, plastic bags, shower curtains, buckets, packaging and soap dispenser bottles. PVC is typically used in plumbing pipes and gutters, shower curtains, blood bags, window frames and flooring. HDPE is typically used in detergent bottles, plastic bottles, plastic bags, bottle caps. As a result of the overuse of plastic products, they are ubiquitous today and therefore one of the most common and persistent pollutants (Huang and Huang, 2007, Andrady and Neal, 2009, Ghosh, 2013, Hahladakis, 2018, Hitchcock and Mitrovic, 2019, Bastante-Rabadán and Boltes, 2024).

Plastics as a common food packaging material

The widespread use of plastic containers in the catering industry has increased concerns about microplastic contamination of food or beverages through forms of food packaging, preparation and cooking. There are increasing reports that larger multinational food companies have reduced their use of plastic packaging (Kędzierski et al., 2020, Shruti et al., 2020). Many studies on food contamination and beverage storage have mainly focused on bottled water (Mason et al., 2018, Oßmann et al., 2018, Winkler et al., 2019, Kankanige and Babel, 2020). Mason et al. (201 8), Kankanige and Babel (2020) have found that microplastic contamination comes from PP and PET bottles, while Oßmann et al. (2018) reported higher microplastic values from single-use PET plastic bottles and, at the same time, from associated caps. The effect of microplastic release from beverage containers has also been tested by Winkler et al. (2019) who found that particles from PET bottles and HDPE caps are a source of contamination of the drinking water stored in these bottles, which contains MP, especially after many bottle opening and closing procedures. Similarly, a mechanical process such as the grinding of salt or other spices, has been associated with finding many microplastic contaminants such as: PET, PMMA, POM and PS polymer particles when using spice mills containing plastics (Schymanski et al., 2020). When it comes to plastic food packaging, it is known that plastic can be peeled off the surface during its use, entailing the release of the MP which gets into food products, putting consumers at risk. Among takeaway containers, the highest release of plastic microparticles was recorded when boxes constructed mainly of PS were subjected to hot treatment with their contents (Du et al., 2020). Similarly, abrasion of microplastic particles caused by repeated washing of melamine bowls that were intended for food storage was observed. In that case, the migration of melamine monomer from cooking utensils was specifically investigated due to potential risks to human health (Ebner, 2020).

Fundamentals of microplastic food contamination

Estimates of MP intake rates currently average up to around 20 per cent of the weight of total food consumed daily (Heraud et al., 2013). One of the most common ways that MP enters the human body is through contaminated food (Kumar et al., 2020). As the number of publications in the field of microplastics in food products increases exponentially, several new studies have reported the occurrence of MP in fruit and vegetables (Oliveri et al., 2020) and packaged meat (Kędzierski et al., 2020). The number of plastic particles was determined in five commonly consumed fruit and vegetables (apples, pears, broccoli, lettuce and carrots) from different grocery shops. Between these food categories, the estimated daily intake of MP particles from fruit and vegetables was higher, averaging 1.50 × 107 particles/capita/day (in adults with a mean body weight of 70 kg) with a median size of approximately 2 μm (Oliveri et al., 2020). Plastic microparticles have also been found in products such as drinking mineral water, beer, tap water, seafood, table salt, canned food, as well as honey and sugar. Low concentrations combined with chronic exposure and ingestion of plastic microbeads by humans pose a potential risk to human health. Scientific reports show that microplastics have become ubiquitous in food and beverages (Liebezeit and Liebezeit, 2013, Yang et al., 2015, Gündoğdu et al., 2018, Karami et al., 2018, Kosuth et al., 2018, Renzi and Blaškovič, 2018, Schymanski et al., 2018). Microplastic contamination of salt is a consequence of the widespread occurrence of plastic waste in the aquatic environment. Gündoğdu et al. (2018) identified MP particles by way of μ-Raman spectroscopy in Turkish salts. These included sea salt (16 to 84 particles/kg), lake salt (8 to 102 particles/ kg) and rock salt (9 to 16 particles/kg). The most common plastic polymers were PE and PP. The results obtained by Kosuth et al. (2018) on salt samples sold in US grocery shops and sourced from various countries around the world were significantly higher (from 46.7 to 806 particles/kg). Yang et al. (2015) also recorded microplastic particles in sea salt, lake salt and rock salt from China ranging from 7 to as many as 680 particles/kg. In all studies, rock salts and well salts were less contaminated than sea salts and lake salts (Yang et al., 2015).

Human exposure to microplastics and its effects

Microplastics that contaminate food have unclear effects on the functioning/physiology of organisms, but increasingly frequent reports describe damage and disease caused by human plastic consumption (Kumar et al., 2022, Bastante-Rabadán and Boltes, 2024), spreading through the food chain, via the dermal route or by inhalation. Once the right research has been done to understand these issues, it will be possible to focus on ways of dealing with the problems caused by overuse of plastics around the world. All food products should comply with production and storage standards and be strictly controlled by the relevant inspections, especially in the area of consumer health and safety. It has been proven that many products consumed are contaminated with MP. Although research in this area has been mentioned previously, there are still gaps in knowledge of the occurrence of microplastics in foodstuffs. There is a lack of standardised methods, techniques and protocols for monitoring and regulatory frameworks for the presence of microplastics in seafood and foodstuffs; therefore, parallel expertise in the consumer market is needed. For a proper definition of microplastics and standardisation methods, it is also important to check the diversity of food consumption around the world. We must understand the term ‘exposure’ as the amount of microplastic that comes into contact with humans in food and drink. Initially, it was not very easy to find measurable amounts of MP in body cells, in the bloodstream or in faeces. According to a recent study, microplastics have been detected in human blood from healthy donors (Leslie et al., 2022). The researchers developed a highly sensitive sampling method and a combined analytical method with dual pyrolysis-gas chromatography/mass spectrometry and measured plastic particles ≥700 nm in human whole blood. The most common polymers there were polyethylene terephthalate, polyethylene and styrene polymers, as well as polymethyl methacrylate. The mean measurable concentration of plastic particles in blood was 1.6 µg/ml in this study group (Schwabl et al., 2019). Other researchers have detected MP in human faecal samples (Schwabl et al., 2019, Zhang et al., 2021) and even in placentas (Ragusa et al., 2021). The researchers speculate that such microplastic particles, which are larger than about 150 μm, are unlikely to be absorbed, while MPs of less than 150 μm can move from the gut to the lymph and circulatory system, causing systemic exposure. The smallest fraction of MP (0.1 > 10 μm) would be able to enter all organs, cross membranes, blood-brain barriers and placentas. In addition, interactions of micro- and nanoplastics with the immune system are expected to have the potential to lead to immunotoxicity, with consequent side effects (i.e. immunosuppression, immune activation and abnormal inflammatory responses) (Bouwmeester et al., 2015, Galloway, 2015, Lusher et al., 2017, Wright and Kelly, 2017). Microplastics have been reported in human colectomy samples obtained from patients with colorectal cancer (Ibrahim et al., 2021). However, these MP particles were comparably large (800-1600 μm) and therefore unable to cross the gastrointestinal epithelium. Particles <150 μm are theoretically capable of crossing the gastrointestinal barrier in mammalian bodies (Hussain, 2001, Campanale et al., 2020). The presence of microplastics degrades the environment and can lead to a number of physiological disorders in living organisms, ranging from reduced growth or reproductive capacity to accelerated death. There are still not enough studies to date confirming the close link between microplastics and food safety. Sooner or later, the entire food chain may become contaminated with plastics and their derivatives (Issac and Kandasubramanian, 2021).

Health consequences of MP particulate pollution

The adverse and long-term effects of human exposure to plastic microparticles are not well understood, given the simultaneous exposure to such particles via several routes and from multiple sources (CIEL, 2019). Although scientific evidence indicates the presence of plastics in many foods, there is no information available on the fate of microplastics in the human body after ingestion of the particles (Wright and Kelly, 2017, Rist et al., 2018). The main challenge at this point is that we do not know the amount of very small MPs, including those of a size capable of penetrating cells, in water, sediments, organisms and air. According to recent studies, the widespread presence of MPs in the environment has raised concerns about MP exposure and its health effects (Agrawal et al., 2024, Borgatta and Breider, 2024). The potential risks of MP ingestion have been widely discussed in a number of studies, which have shown that MP uptake from contaminated soil can expose people to disease (Wright and Kelly, 2017, CIEL, 2019). Plants (fruits and vegetables) tend to accumulate these toxic chemicals from the soil (Li et al., 2019). Most microplastics are derived from polymers that resist chemical degradation in vivo. Their biological stability, size and shape, together with their dose and stability, are important factors contributing to their impact on health. If they enter the body by inhalation or ingestion, they may also be resistant to mechanical removal, adherence or deposition (Wright and Kelly, 2017). The results suggest that they can move through living cells into the lymphatic or circulatory system, potentially accumulating in secondary organs or affecting the immune system and cellular health (Brown et al., 2001, Rieux et al., 2005, Frohlich et al., 2009). After microplastic ingestion, particles smaller than 150 μm can travel to the lymph and circulatory system, and particles smaller than 20 μm can penetrate some organs (Barboza et al., 2018). The smallest plastic nanoparticles can enter all organs and be transported across cell membranes (Bouwmeester et al., 2015). A number of laboratory studies have demonstrated cellular uptake of MPs using various human cell lines. Some researchers have conducted laboratory experiments with PS molecules in lung cells and human gastric adenocarcinoma cells respectively, demonstrating induced pro-inflammatory responses (Walczak et al., 2015, Forte et al., 2016, Fuchs et al., 2016, Liu et al., 2018). The direct effects of MPs are cytotoxicity, inflammation and the production of reactive oxygen species (Elsaesser and Howard, 2012). In addition, BPA as a component of cans and other food packaging causes endocrine disruption and is able to migrate out of polycarbonates, adhering to food or beverages and consequently can be ingested by humans (Calafat et al., 2008). It can cause breast and prostate cancer in mammals, possibly promoting the same types of cancer in humans 2014). Studies have shown that other chemicals present in plastics or adhering to microplastics, such as low molecular weight styrene residues, polyvinyl chloride monomer and pharmaceuticals, can become carcinogenic, mutagenic and endocrine disruptors and can cause cardiovascular disease (Halden, 2010, Zeng et al., 2022). The distribution of plastic particles of 1-10 μm in tissues and organs in the body as a whole is still unknown, however, it is known that they can accumulate in specific tissues (Powell et al., 2010). In some nanoparticle studies, the liver and the spleen have been identified as the main target organs, e.g.: for silver nanoparticles (Gaillet and Rouanet, 2015). Microplastics have been found in lung cancer tissues collected from patients with various types of cancer (Chen et al., 2022). According to other studies, oral exposure to MP contamination causes hepatitis, neurotoxic reactions, decreased body weight, decreased mucin excretion in the colon, altered amino acid and bile acid metabolism and altered microbiota composition (Lu et al., 2018). Six different polymers found in peripheral organs, in particular in the liver of patients with chronic liver disease, were recently analysed (Horvatits et al., 2022). Previous studies have assessed the role of microplastics as a chemical vector in humans (EFSA, 2016, FAO, 2017). Microplastics can accumulate other organic pollutants and transport them, which is why MP is called a ‘Trojan horse’ for pollutants and toxic substances (Hildebrandt, 2021). Some studies on the uptake of chemicals by plastics in the environment have shown that MPs can bind metals (Ashton et al., 2010, Holmes et al., 2012, Vedolin et al., 2018). Among these metals, mercury is of particular importance as it is a global contaminant common in the marine environment and is highly toxic to animals and humans (Eagles-Smith et al., 2018). In addition to chemicals, MP particles can absorb bacteria and other microorganisms that have been found on plastic waste. Referred to as the ‘plastisphere’, it can also include exotic invasive pathogen species that contribute to biodiversity loss and other negative ecological and economic impacts across the planet (Zettler et al., 2013, Bastante-Rabadán and Boltes, 2024).

Summary

As a result of far-reaching consumerism of our times, there is a threat posed by an excess of manufactured plastics, which represent waste that does not naturally occur in the environment. They have very long decay periods during which many chemicals, often toxic, are released into the environment, leading to secondary pollution (Piontek, 2019). Plastics, due to their multifaceted applications, were supposed to improve the quality of human life. This was the case in many areas because, for example, packaging for food, cosmetics, etc. provides good protection to help keep products fresher for longer. However, the overuse of plastics is leading to a global environmental catastrophe (Jastrzębska, 2020).

The annual global demand for plastics has grown steadily in recent years to around 245 million tonnes, of which around 50 million tonnes is accounted for by plastic use in Europe. The use and manufacture of plastics involves the consumption of significant amounts of fossil fuels, with negative consequences for the environment and climate change. Apart from the cost of manufacturing and recycling these materials, the biggest concern of our time is the microplastic contamination of all the environments (Andrady, 2011, Plastics Europe 2021). Unsorted plastic waste, such as plastic bags, disposable cutlery and packaging, inevitably mixes with food waste during disposal. MP in the soil is then taken up by plants, leading to consumption by humans or animals (Khalid, et al. 2020) In 2020, almost 10.2 million tonnes of post-consumer plastic waste were collected and sent for recycling (locally or outside Europe) in Europe. In 2021, plastics manufacturers have planned numerous investments in chemical recycling technologies, with the value of these investments expected to increase from the €2.6 billion envisaged for 2025 to €7.2 billion in 2030. It has yet to be estimated how much of the 80 million tonnes of packaging plastics (including single-use items commonly found in beach litter) consumed worldwide each year ends up in the oceans (Andrady, 2011, Plastics Europe 2021). Plastics have thus become an integral part of our daily lives, as they are a versatile, lightweight, strong and potentially transparent material, ideally suited for a variety of uses, including toys, furniture or other home furnishing accessories such as lamps, fittings, etc. They have replaced natural materials used for these purposes, such as: wood or metals. Their low cost, excellent oxygen/moisture barrier properties, biological inertness and low weight make them excellent packaging materials. Unfortunately, they are replacing conventional materials such as glass, metal and paper, as well as classic textiles, which include cotton and linen. According to the EEA study on plastics in textiles, European consumers throw away around 5.8 million tonnes of textile products each year – equivalent to around 11 kg per person – two thirds of which are synthetic fibre products. According to available data for 2017, households in Europe consumed approximately 13 million tonnes of textile products (clothing, footwear and home textiles). Textiles made of plastics account for about 60% of clothing and 70% of home textiles, so it is important to promote consumer sense and moderation, and to control microplastic emissions in the environment, which will raise awareness of the scale of the problem (EEA, 2024). It is estimated that between 200,000 and 500,000 tonnes of microplastic fibres from textiles enter the marine environment each year (Sherrington, 2016, Ellen MacArthur Foundation, 2017).

It seems reasonable to undertake more public education campaigns addressed to children and young people. Healthy and sensible consumer choices can also be promoted as often as possible in academic circles. It is important to emphasise the importance of choice as the awareness present every day in the case of not only purchases, but also cosmetic procedures, e.g. hybrid manicure, during which the exchange in the process of mechanical abrasion creates a lot of MP particles. There has been a growing body of research on the effects of MP’s chemical and molecular toxicity on human health recently, but the development of technologies and strategies for the disposal and eventual destruction of MPs, i.e. the development of closed-loop systems such as chemical recycling and thorough regulations to reduce plastic consumption and create safe plastics, are still worth pursuing (Meegoda and Hettiarachchi, 2020). While better design, manufacture, collection, reuse, repurposing and reprocessing/recycling of plastic items is needed, what is required for the most part is a reduction in the use of plastic materials in the first place, particularly for single-use packaging (Rhodes, 2019). Researchers’ efforts are focused not only on building the knowledge base related to the risk of human exposure to MPs, but may also be directed towards the use of specific techniques to clean water or air of MPs, e.g. improving the capture of microplastics in practice, e.g. through filters in washing machines to reduce microplastic emissions to water and air when washing clothes, or in water purification systems in treatment plants, as well as soil treatment (EC, 2020a, Grbic et al., 2019, Ramage et al., 2022).

Individual consumption is by far the strongest determinant of environmental impact (Wiedmann et al., 2020). The increasing consumption is well ahead of the possible positive impact of technological innovations, which, as it turns out, can only slightly reduce the pressures on ecosystems (Lan et al., 2016). Therefore, if we want to counter environmental catastrophe, the focus should not so much be on technological solutions or limiting the growth of the human population but on stopping the ever-increasing consumption.

Conclusions

Giving up plastics is difficult because, being used in almost every area of life, they are an ideal material for innovation, which very often turn out to be impossible with other materials. Reducing plastic consumption requires fundamental and radical changes in the behaviour and value systems of both consumers and business. Plastics have become a ubiquitous and convenient formula for both the packaging and materials of most everyday objects. This form has unfortunately become firmly entrenched in our consumer choices, for which it is difficult to find an equivalent alternative among the traditionally used materials. However, as the famous researcher Jane Goodall, an ethologist and anthropologist, said: “we cannot live out our days without having an impact on our environment”, so each of us decides our consumer choices and each of us has, in part, an impact on the world around us and how it works.