Microplastics- the yet invisible macro problem in the world.

Plastics as we all know are a wide range of synthetic or semi-synthetic organic compounds that are used to form a large number of useful objects for day to day requirements. The most talked about topic on plastics is plastic pollution. Since plastics are highly durable polymers, it takes hundreds of years to decompose and the plastics thrown away, linger in the environment for long periods of time. However not only the environment, animals and plants can also get ‘polluted’ by plastics. This is due to microplastics entering plants through water absorption by roots or ingestion of food along with microplastics by animals. This article is an introduction to microplastics, how likely microplastics affect human lives and the environment, and the methods of remediation to this problem.

Microplastics are small pieces of plastic less than 5 mm in length which occur in the environment as a consequence of plastic pollution. Many people are of the belief that microplastics result from degradation of used plastic items, however, there are two types; the primary and secondary microplastics. Primary microplastics are tiny plastic particles designed directly for commercial use such as microbeads in some abrasive toothpastes, skin scrubs, microfibers in textiles, and are released to the environment after usage. Secondary microplastics are tiny particles resulting from the breakdown of larger plastic items such as toys, polythene bags and bottles.

Microplastics are persistent and difficult to degrade into individual atoms due to their small size. Therefore, they get accumulated in almost all the ecosystems on earth from deep oceans to agricultural soils and even high up in mountains, because the smallest microplastics can form dust particles. They have been found in the tissues of plants, aquatic fish, and land animals as well. Scientists have found microplastics in human stool, tissues, and organs. Even though the effect of microplastics to humans is not yet understood, studies have shown that microplastics in the diet of aquatic fish, result in generating less energy for the fish because of its indigestibility, ultimately causing death. The accumulation of microplastics can result in major loss of biodiversity in the years ahead.

Microplastics exist in the air we breathe, the food we eat, as well as in our bodies. It was estimated that the ocean surface contained 5.25 to 50 trillion pieces of microplastics in the year 2014. The atmosphere holds tons of microplastic fibers and therefore, found in the air we breathe. According to a research conducted in Greenland in 2019, it was found that people consume at least 50,000 microplastic particles per year along with food.

Due to the continued worldwide use of plastics, used plastics are discarded into landfills, which causes more and more microplastics being released to the environment. The actions that can be taken to mitigate accumulation of microplastics and removal from the ecosystems are of various methods. Due to the small size of microplastics, they cannot be physically separated from the environment. The simplest method of remediation is to stop the use of plastics altogether, especially the use of primary microplastics in commercial products. However, the plastics in the landfills will degrade and add more secondary microplastics into the environment.

The immune system has been evolved to protect the body from any foreign organism or particle since, foreign objects are usually unfavorable for the functioning of the body. There is no doubt that microplastic accumulation in animal tissue will result in adverse reactions or alter the normal functioning of the body due to the formation of impenetrable barriers. Therefore, even if environmental pollution may not be a life-threatening aspect to many people, the possibility that microplastics could remain wedged into human tissues must make it a concern to many. This problem cannot be ignored and should not be ignored.

Therefore, the most successful method of remediation is to use microorganisms capable of degrading microplastics. There are several bacterial species such as Bacillus amyloliquefaciens, B. subtilis, B. cereus and Pseudomonas putida that are capable of degrading microplastics. In addition, there are microplastic degrading fungal species such as Pestalotiopsis microspora and Aspergillus flavus. Pestalotiopsis microspora can degrade polyurethane, even under low oxygen conditions. These microbes secrete hydrolytic enzymes, which depolymerize polyurethane. Usage of microplastic degrading microbes would be a promising solution for reducing microplastic pollution.