Microplastics: Health Consequences for Humans and Aquatic Life

ADITI MADHUSUDAN – Microplastics are very small pieces of plastic that are under five millimeters long. Although their size might make them seem insignificant, they can potentially create large issues for humans and aquatic life alike. Microplastics are generated by the breakdown of larger plastic items over time. A subclass of microplastics composed of polyethylene are also intentionally added to some commercial products, specifically health and cosmetic products, to act as exfoliants. The sheer quantity of microplastics present in the ocean causes them to be a significant source of pollution despite the diminutive size of the individual particles. They constitute about three percent of the eight million metric tons of plastic deposited into the ocean per year. Plastics, both intact objects and microplastics, often end up in the ocean due to human consumption of products containing microplastics and environmental factors such as storms, water runoff, and winds. 

Microplastics in oceans and other bodies of water are a threat to the health of both aquatic animals and humans. Plastics are non-biodegradable and can therefore accumulate in the bodies of fish, shellfish, and other aquatic animals who ingest them. Consumption of microplastics has been linked to many negative outcomes—blockage of digestive tracts, reduction in eating, alteration of feeding behaviors, and starvation— among aquatic creatures, turtles, and birds. These health consequences can ultimately impact a species’ ability to grow and reproduce. In addition to their effects on aquatic creatures, microplastics also pose a threat to human health. They can enter the human body via inhalation or ingestion and have been detected in both seafood and drinking water. While more scientific studies are needed to better understand the effects of microplastics on human health, a preliminary study found that when lung cells were subjected to levels of polystyrene found in the environment, there was a decline in the speed of the cells’ metabolic processes, change in shape and declustering of the cells, and inhibition of cell proliferation. 

In recent years, the harmful effects of microplastics have caught the attention of government officials and influential organizations. In December 2015, Congress passed the Microbead-Free Waters Act of 2015, which prohibits people or organizations from manufacturing, distributing, or packaging microbead-containing cosmetic products that can be rinsed off. Considering that water treatment facilities are currently not able to completely remove microplastics, this act prevents some— but not all— of the microplastic contamination in drinking water. In 2019, the European Chemicals Agency (ECHA) suggested restrictions on the intentional usage of microplastics for products on the EU/EEA market. The United Nations also acknowledged the threat of microplastics and need for regulations in a 2017 resolution. As more research continues to be done on the effect of microplastics on the well-being of humans and aquatic creatures, it is likely that more regulations will be passed regarding these substances. Especially considering the role of plastics as adsorbents for certain pollutants and heavy metals, it is crucial to understand the expansive implications of microplastic use and proceed to take action in a timely manner to preserve the health of living organisms.

Copy Editor: Alina Baiju

Photography Source: Shweta Mistry