Useful or Dangerous: How Plastics Affect Life in the Marine Ecosystem?
The history of plastics began in the mid-1880s with the synthesis of a polymer called polyvinyl chloride (PVC) and continued by the discovery of bakelite, the first real synthetic, by Leo Baekeland in the early 1900s1. Since plastics have extraordinary properties such as versatility, durability and transparency, this material has become unique for the industry, medicine and food protection2. However, plastics cannot degrade easily and can persist in the environment for a long time2. The persistence of plastics leads to pollution by accumulation in the environment if there is uncontrolled release or unselective discard2. Plastic pollution was first detected in the 1950s on land and after that, increase exponentially3. Plastics are found as microplastics in oceans4. In the early 1970s, microplastic pollution in the marine environment was determined and reached 322 million tons in the oceans by 20153,4. A recent report indicates that the highest microplastic concentration in deep-sea sediment is determined as 1.9 million per square meters5. Therefore, it becomes a global problem and this essay aims to display how serious pollution is and how it affects organisms.
Plastics are called chemical cocktails because they contain plastic polymers with chemical additives and production byproducts6. Plastics also contain environmental contaminants in their structure6. The plastic polymers are not toxic but some of the monomers of these polymers can be toxic6. For example, vinyl chloride is the monomer of PVC and has proven to be mutagenic and carcinogenic6. When plastics are degraded by environmental factors, the monomers of the plastic polymers are formed and act as pollutants6. Also, production byproducts can be catalysts, organic solvents or surfactants and they are hazardous for the environment6. The chemical additives are required to improve plastic quality but they can be persistent organic pollutants (POPs), leach from the plastics to the environment and result in pollution6.
Microplastics are plastic particles and have a size smaller than 5 millimeters4. There are two types of microplastics: primary microplastics and secondary microplastics2,7. Primary microplastics are found directly in products such as cleaning products for surfaces, cosmetics, personal care products2. However, secondary microplastics result from the breaking of plastics over time by environmental factors such as high temperature or ultraviolet light2. When plastics are in the form of microplastics, they cannot be seen by the naked eye but they still lead to pollution7. If the size of the plastic is smaller, the leaching of additive chemicals will increase6. In addition, the smaller size of plastics means that the shorter polymer length and this shortening lead to increase intermolecular interaction and thus, increase the holding of potential pollutants6. As a result of microplastics formation, pollution becomes more dangerous6.
Besides the others, there is one more danger about microplastics: they can be ingested by marine organisms2,6. If an organism tries to ingest a microplastic particle, the particle can cause physical damage to the digestive tract by penetration or obstruction2,6. These physical damages result in starvation and eventually death due to obstruction by microplastics2. Also, microplastics are vectors that carry toxic material in their structure and when they are ingested, the ingesting organism is exposed to the toxic substance and the other organisms in the food web, which interact with the organism by feeding, are exposed to the toxic substances and microplastics2,4,6. Another negative effect of microplastics on organisms is the reduction in survival, growth and reproduction rate4,6. When an organism ingests microplastic fragments, microplastics cannot be digested because there are no enzymatic pathways to break down polymers like plastics7. While the microplastics cannot completely be broken down from their monomer, they can break down into nano plastics with sizes smaller than 1 micrometer6. The ingested microplastics accumulate in organisms and can travel through the tissues when they are degraded to nanoplastics2,6. It is shown at the cellular level that the accumulated microplastics result in inflammation or oxidative stress which is dangerous for the genetic material of the organism6. Polystyrene nano plastics are proven to inhibit photosynthesis in algae6. Above all, it has been proven that nano plastics can pass through the blood-brain barrier and lead to brain damage in fishes6.
The current level of plastic pollution is very serious, but still, plastic waste is increased due to human demands and worldwide problems and accelerate pollution. Humanity fighting with a pandemic situation caused by SARS-CoV2 and result in COVID-19 disease8. Preventing the spread of COVID-19 disease requires protective equipment and the use of surgical face masks to protect COVID-19 significantly8. The surgical face masks are disposable and made with different polymeric materials such as PVC, polystyrene or polyesters8. The material changes depending on the manufacturer but generally, nanofiber plastic materials are used for the filtering layer of the masks8. These face masks are discarded after a single use and contribute to plastic pollution because most of them are unrecycable8. There are some options for manufacturing face masks other than polymers like silk or cotton but these materials have not been approved as protective material by World Health Organization8. Before the pandemic, face masks had been frequently using in developed countries like China8. However, the use of face masks has been significantly increased due to the pandemic8. For instance, when China is examined by its face mask production, it is seen that the production increased twenty times with the pandemic in June of 2020 and reached 200 million face mask production per day8.
Studies examining plastic pollution and the effects of plastic pollution on organisms are very challenging due to the unstable environment and multiple factors affecting the organisms. However, it can be simply concluded from the essay and the current studies that plastics are dangerous as much as they are useful. Plastics are not easily degraded in nature and damage to organisms. Waste management and recycling strategies must be improved to fight plastic pollution. On the other hand, there are some limitations about recycling such as, not all the plastics can be recycled or the dirty plastics cannot be recycled9. Also, the polymers of plastics become shorter in each recycling and therefore plastics can only be recycled 2-3 times due to a decrease in the quality of the plastics9. The only effective way to fight plastic pollution is to reduce plastic production. However, many products require plastics to exist or to be protected and thus, a new material that can be replaced with plastics but less harmful to nature should be used. There is no material that has yet been discovered but there have been some promising studies with specific algae species continuing. Aragaw points out that ‘the microplastic pollution, being adding face masks together, maybe the next worldwide pandemic’8. This is the reality and pollution should be handled immediately.
- History of Plastics. https://www.plasticseurope.org/en/about-plastics/what-are-plastics/history.
- Guzzetti E, Sureda A, Tejada S, Faggio C. Microplastic in marine organism: Environmental and toxicological effects. Environ Toxicol Pharmacol. 2018;64:164-171. doi:10.1016/j.etap.2018.10.009
- Ríos MF, Hernández-Moresino RD, Galván DE. Assessing urban microplastic pollution in a benthic habitat of Patagonia Argentina. Mar Pollut Bull. 2020;159. doi:10.1016/j.marpolbul.2020.111491
- Horton AA, Barnes DKA. Microplastic pollution in a rapidly changing world: Implications for remote and vulnerable marine ecosystems. Sci Total Environ. 2020;738. doi:10.1016/j.scitotenv.2020.140349
- Kane IA, Clare MA, Miramontes E, et al. Seafloor microplastic hotspots controlle by deep-sea circulation. Science (80- ). 2020;368(6495). doi:10.1126/science.aba5899
- Reimonn G, Lu T, Gandhi N, Chen WT. Review of microplastic pollution in the environment and emerging recycling solutions. J Renew Mater. 2019;7(12):1251-1268. doi:10.32604/jrm.2019.08055
- Andrady AL. Microplastics in the marine environment. Mar Pollut Bull. 2011;62(8):1596-1605. doi:10.1016/j.marpolbul.2011.05.030
- Aragaw TA. Surgical face masks as a potential source for microplastic pollution in the COVID-19 scenario. Mar Pollut Bull. 2020;159. doi:10.1016/j.marpolbul.2020.111517
- Plastic Recycling. https://blog.nationalgeographic.org/2018/04/04/7-things-you-didnt-know-about-plastic-and-recycling/#:~:text=RECYCLING PLASTIC DOWNGRADES ITS QUALITY.&text=In other words%2C it’s what,can no longer be used. Published 2018.