The enormous production of plastic items has led to increased pollution in the World. Besides information and research, still little is known about microplastics’ interactions within the environment. Tiny plastic particles can release multiple harmful chemical compounds affecting organisms. Hence, it should be ascertaining mechanisms behind further microplastic liveliness. In that case, we must consider what the microplastic is.
Plastic materials are used in almost every aspect of society. Food is packaged into plastic foil, boxes, or bottles; medicines are mainly packed into plastic bottles, almost all shoe soles are also made with plastic. What about transportation? Just take a look around; cars are full of plastics. These light and elastic polymers can be found even in sport and leisure, electronics, agriculture, design, buildings, and construction. It is difficult to imagine the world without it. Why is it so popular? Due to its functional properties, strength, durability, low costs of production, and resistance to corrosion making lives easier. Due to the global use of microplastic it easily gets to an environment like soil and water, especially when it is in microplastic form. Is microplastic harmful for living organisms? First, let us remind you what microplastic is.
We can define it as tiny plastic debris between 100 nm to 5 mm in size, but recently researchers have focused more on mezo and nanoparticles that can invade a more extensive range of environments, causing explicit health problems. Ubiquitous nanoplastic was detected in almost all niches in the environment. Study towards plastic chemistry is tentative, especially those connected to aquatic systems and the atmosphere. It is associated with a broad range of external factors which impact plastic particles, then rigidity and porosity increase what creates greater affinity and thus is more available for other chemical compounds . There is no evidence of the survivance of these components in different environments. More viscous and unveiled microplastic is readily available for many chemicals like heavy metals, hydrocarbons, polycyclic aromatic hydrocarbons, residues from drug transformation, microorganisms’ secondary metabolites, and more. All of this in corollary generates new types of toxic pieces of micro or nanoplastic with additional and integral forms of toxic particles. In a further perspective, new findings and impact on the environment show that plastic particles can be transferred and vector of different types of chemicals, then incorporated into food chains to top consumers and affect their health. Recent studies show that plastic materials left in aquatic systems can release many compounds like pigments. Some of them are safe, while others are harmful to health. Once they get to the environment, they pollute it and affect living organisms .
What can we do?
First: proper recycling! Second: reduce the use of plastic!
Is microplastic harmful to living organisms, and does it degrade faster than bulk plastics like plastic bottles? First of all, we have to know the chemistry that stands behind microplastics.
Have you ever wondered what kinds of plastic you use for food packaging or for bringing water while hiking? Each plastic that we use has a symbol that gives information on the type of synthetic material that it is made of. Plastics are fossil-derived.
Effectively plan a recycling program. Measurements show that fishing nets are mostly made of polymers such as polyethylene (PE), low-density polyethylene (LDPE), high-density polyethylene (HDPE), polyurethane, polyvinyl chloride (PVC), polystyrene (PS), polyethylene terephthalate (PET), polypropylene (PP). All additional components such as pigments, plasticizers, or combustion retarders are an obstacle and disable a complete homogenization of the material. Remains of catalyzers of polymer synthesis such as sulfur compounds can also be found . What about symbols? Some symbols have a number additionally.
To facilitate the systematics of polymers, we use symbolic labeling in which:
PET 1 – number 1 inside the triangle means the plastic is made with polyethylene terephthalate. That is one of the most widely used plastics in the world. Most bottles and packaging are made from it. It is recyclable, but repeated use and contact with factors such as sunlight or high temperatures can release toxic substances. PET 1 bottles are usually single-use.
HDPE – 2 means that it is high-density polyethylene, one of the safest and most recyclable types of plastic. It is currently used to package dairy products.
PVC 3 is polyvinyl chloride; it is very dangerous and produces a lot of toxins when burned. It is used in the production of construction and medical materials.
LDPE 4 is a low-density polyethylene that is quite safe and is used in the production of advertising bags or films.
PP 5 is polypropylene; it is recycled and can be used to insulate electrical cables.
PS 6 is polystyrene, also known as Styrofoam, which is dangerous and produces toxic compounds when burned. Its surface is porous, being an ideal surface for microorganisms settling.
OTHER 7 are all other plastics and may contain bisphenols that are harmful to organisms.
BPA FREE – This means that plastic does not contain bisphenols.
In addition to the danger coming directly from the microplastic, the substances on the surface of the plastic particle are also very harmful. Among them, we can distinguish bisphenols mentioned above and phthalates. Bisphenols have endocrine effects by disrupting hormone production or becoming similar to hormones. Phthalates also affect reproduction in animals by interfering with gametes. Tiny plastic particles can also be coated with pharmaceutical waste causing drug resistance in some bacterial strains, promoting the spread of these organisms, allowing them to form entire colonies. In this case, the plastic particle becomes a dangerous carrier of pathogens that can be ingested by humans drinking the water.
Microplastics are also often unknowingly ingested by fish who mistake them for food. Very often, it ends up in the bloodstream, as a result of which dangerous lesions can form, but scientists have not thoroughly studied this aspect. Nanoplastics (up to 100 nm size) can easily pass through different parts of the body, such as skin, liver, or even heart, where they can cause damage.
Microplastics are also a common part of cosmetic products. It is found therein in huge quantities and is non-biodegradable. For example, polyethylene and polypropylene are found in scrubs and toothpaste, polyethylene terephthalate is found in nail polish and packaging, or polyester is found in hair conditioners because it contains a lot of viscosity regulators. Those little granules we rub on our faces are plastic. The European personal care and cosmetics sector account for up to 2% of total emissions. These are very large quotations, but some states have already banned the use of plastics in these types of productions.
Did you know that?
- Ghost nets are fishery nets that were left in aquatic systems. They float in the seas and oceans, releasing many toxic compounds to water. The constant movement of water and sea waves causes their defragmentation into microplastic and nanoplastic that get easily to organisms living in the water.
- One of the main sources of microplastics in an environment is the textile industry. Each time we do laundry, tiny particles of fibers get to the water. When the fabric is synthetic, fibers do not decompose natural fibers likewise. So, they become pollutants.
- The fact that some synthetic products are called eco-friendly does not mean that they are biodegradable. Quite often, they are just reused fossil-derived materials.
- Glitter is mainly made of plastic that easily gets to an environment? Once we use it, it is flushed away in pipes and then can get even to soil and drinking water—all due to its small size that cannot be effectively filtered.
- Birds can remove microplastics from the body through the process of regurgitation, which involves moving food contents containing hard debris from the stomach into the esophagus.
- The largest amount of micro-plastic particles is predicted to be in the North Atlantic vortex area located at the height of the subtropical zone because this is the location of large convergence.
This article is a joint work of Ewa Borowska (MISMaP, University of Warsaw), Martyna Łuszczek (Faculty of Chemistry, University of Warsaw), and Magdalena Osial (Faculty of Chemistry, University of Warsaw) as a part of the Science Embassy project. Image Credit – Ewa Borowska.
 Kane IA and Clare MA (2019) Dispersion, Accumulation, and the Ultimate Fate of Microplastics in Deep-Marine Environments: A Review and Future Directions. Front. Earth Sci. 7:80. doi: 10.3389/feart.2019.00080
 Dąbrowska A, Łopata I, Osial M, Ghost nets phenomena from the chemical perspective, (2021) Pure and Applied Chemistry 93(4). doi: 10.1515/pac-2020-1102
 Lusher A, Hollman P, and Mendoza-Hill J, (2017) Microplastics in fisheries and aquaculture, Status of knowledge on their occurrence and implications for aquatic organisms and food safety, FAO FISHERIES AND AQUACULTURE TECHNICAL PAPER, 615, ISSN 2070-7010