By: Vivien Lopez, 10th. of February 2023
This post is supporting a series of Facebook posts where In The Same Boat describes the 4 main reasons to clean plastics from the beaches. Reason nr. 3 of 4 is to protect ecosystems and our food chain from microplastics and the toxins that follows, and that are potentially harmful also for humans.
The issue of microplastics in our oceans is a topic that worries In The Same Boat. Because of the large presence of these particles and the threat they pose to an entire ecosystem by disrupting the food chain.
Microplastics are defined as synthetic polymeric particles smaller than 5 mm in diameter. They are categorized into two different sources: primary and secondary.
The primary source of microplastic – Microbeads and granules
The primary source includes all plastic materials whose size during production already corresponds to that of the microplastic. Among these, we find a large proportion of personal care products. These are present in the form of plastic microbeads, which are insoluble in water and degrade very slowly. Then there are also plastic granules. These plastic particles are used extensively in everyday life. They are found in building materials, in the clothing industry, in chemicals, in household products and in agriculture.
These plastic granules are very small in size and are produced in large quantities. Paint debris also belongs to this category. They come from layers of paint that have accumulated and then been degraded by various phenomena, such as erosion or abrasion. Depending on the nature of the paint, which may be more or less harmful to the environment, tiny plastic particles are formed and easily spread.
Wastewater can also carry microplastics, releasing large quantities of synthetic microfibers from various textiles, including polyesters and polyamides.
It was also found that effluent from wastewater treatment plants can contain very high concentrations of microplastics. The latter is mainly from the industrial field and is discharged into natural waters.
The secondary source of microplastic – Degradation of macroplastic
The second source of microplastics is the one derived from larger particles that have not been recycled and have degraded in the environment. The formation of microplastics, in this case, is induced by various processes, such as aging by light irradiation or mechanical crushing. These plastics are mainly plastic bags, plastic bottles, all disposable kitchen utensils (plates, glasses, cutlery, straws, etc.), packaging (food, clothes, etc.), or fishing waste (buoys, fishing nets, fishing line, etc.).
Once in our oceans, microplastics are very easily ingested or inhaled by animals. Plastic particles have been found in the guts of a wide range of species, from deep-sea species to large mammals and seabirds. This means that plastics are spreading throughout marine populations, including through the food chain, by crossing the species barrier through predation. Moreover, these particles take a very long time to degrade and are very difficult to evacuate by the body, which gives them time to spread widely by being transported via the animal’s movements and thus colonize other marine environments.
As they accumulate in the body, microplastics disrupt the body’s vital functions. They can affect fertility by reducing it, activate the immune response by triggering inflammatory reactions, alter metabolic functions, reduce nutrition, and disrupt the growth of the organism. The accumulation of microplastics could also, in the long term, block gastrointestinal functions, notably by inducing intestinal damage. By penetrating the gills, microplastics reach the respiratory system.
They are even found in the lymphatic and bloodstream. They enter the liver, kidneys, and digestive organs. The photosynthetic activity of plankton is also impaired by plastic pollution. Polluted waters could, therefore, negatively affect the capacity of our oceans to produce the oxygen we breathe.
In addition, plastic molecules have the ability to absorb chemicals through a phenomenon of molecular adhesion. This depends on the nature of the plastic, its size, its color, and also its age. As plastic is modified by its environment, the latter has a significant influence on its ability to adhere. The hydrophobic nature of plastic favors interactions with other hydrophobic substances in the environment, which are potentially toxic.
More specifically, the molecular composition of microplastics allows for various types of chemical interactions to take place. These favor the nature of the affinity of the plastic and, therefore the specific substances that can be absorbed into it. It would therefore seem that the attraction of different pollutants to specific plastics depends on the constantly changing environment and the physicochemical properties of the two substances.
These toxic substances may concern chemical elements such as heavy metals, which can have severe consequences on the body when present in high concentrations. Indeed, the latter accumulate in the muscles and the brain and cause numerous disturbances, particularly at the level of enzymatic activity.
The real danger of this phenomenon comes from the fact that the microplastics present in the organism act as a reservoir in which pollutants will accumulate over the course of the organism’s existence before spreading to another species.
This threat today also concerns us because we are an integral part of the food chain, and our consumption of marine species leads us to ingest a number of plastics, polluting our bodies.
Similarly to other living organisms, we are affected by the harmful effects of plastic particles. Once the cells are affected, the organic functions can be altered, affecting the circulatory systems, particularly the lymphatic system, and thus indirectly impacting our immune system. We also find all the other problems seen earlier (liver problems, inflammation, intestinal damage, etc.). However, we are not yet in a position to measure the full extent of the damage caused by the incorporation of plastics in the body, as these studies are still very recent. However, the studies published so far largely prove the seriousness of this problem and the urgency to act to prevent the situation from getting worse.
In order to reduce the appearance of microplastics, ITSB has set itself the goal of cleaning the beaches of plastic waste before it degrades into small particles that are much more harmful and difficult to extract from the environment.
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