Plastics in the ocean – more than unsightly, an unseen health hazard

Plastic waste is accumulating in the world’s oceans at a rate of about 8 to 10 million tons per year, according to a recent Al Jazeera article. As a size comparison, if all the plastic was gathered into one mass, with the thickness of a plastic bag, it would currently cover a surface area the size Jamaica. In 50 years’ time, this increases to a surface area equivalent the size of France. However, what is seen on the surface is only the figurative tip of the iceberg – about 99% of that plastic mass is below the surface, or accumulating on the ocean floor. The vast majority of the plastic waste enters the oceans from Asia, accounting for about 80%.

https://www.aljazeera.com/news/2023/6/8/how-much-plastic-is-in-our-oceans-infographic

Beyond the immediate impacts of plastic waste on wildlife, such as injury or death by ingestion or entanglement affecting around 240 animal species (1), the breakdown of plastic waste releases greenhouse gases (2), inhibits photosynthesis in aquatic flora (3), and is the source of microplastics, or plastic particles nanometers in width up to 5mm in diameter. Research indicates that microplastics negatively impact human health in a variety of ways, including reproductive and developmental harm, inducing immune response, and contributing to metabolic disorder (4).

The impacts of plastic pollution are felt around the globe. Microplastics have been found in every corner of the world, however remote, from the highest mountains to the deepest parts of the ocean (4). And although the majority of plastic pollution entering the oceans originates in Asia, it does not necessarily reflect where the plastic products were initially consumed and discarded – developed nations ship plastic waste to countries that have a difficult time properly managing it (5). This further reflects what is observed with greenhouse gas emissions – when pollution occurs in a closed system such as our world, the consequences are felt by everyone, regardless of their contribution.

Confronting this problem with a couple of different approaches could reduce or stop the flow of this waste into the oceans. First, the impact of microplastics on human health must be prioritized in research to better understand the health risks and biological mechanisms by which microplastics affect human health. A better grasp of the significance of the problem will facilitate public awareness, which in turn may influence individual behaviors and public policy worldwide.

Second, it is clearly necessary to reduce the amount of plastic entering the environment. This should be done in a manner that is conscious of the economic drivers and root causes of the heavy use of plastic and its improper management, in particular in the countries producing much of the plastic waste. Economically viable alternatives for single-use plastics should be identified. Locally, improved waste management may be achieved through social awareness. And for the plastic waste that has already made its way into waterways, improved extraction methods should be activated at the source, such as that being deployed by Sungai Watch in Indonesia (6) and Living Lands & Waters in the USA (7).

- Mark Anderson

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1 – Johnson, C. (2021). ‘Whales and the plastics problem’, Stories, World Wildlife Fund, Feb 18. https://www.worldwildlife.org/stories/whales-and-the-plastics-problem#:~:text=Ocean%20plastic%20pollution%20harms%20marine,in%20internal%20injuries%20and%20death.

2 – Royer, S. et al. (2018). ‘Production of methane and ethylene from plastic in the environment’, PLoS ONE, 13(8): e0200574. DOI: https://doi.org/10.1371/journal.pone.0200574.

3 – Zhang, C. et al. (2017). ‘Toxic effects of microplastic on marine microalgae Skeletonema costatum: Interactions between microplastic and algae’, Environmental Pollution, 220(B) pp. 1282-1288 [Online]. DOI: https://doi.org/10.1016/j.envpol.2016.11.005.

4 – Li, Y. et al. (2023). ‘ Potential Health Impact of Microplastics: A Review of Environmental Distribution, Human Exposure, and Toxic Effects’, Environment and Health, Article ASAP, Aug 10. DOI: https://doi.org/10.1021/envhealth.3c00052.

5 – McCormick, E. et al. (2019). ‘Where does your plastic go? Global investigation reveals America's dirty secret’, The Guardian, Jun 17 [Online]. Available at: https://www.theguardian.com/us-news/2019/jun/17/recycled-plastic-america-global-crisis.

6 – Sungai Watch. Available at: https://sungai.watch/.

7 – Living Lands & Waters. Available at: https://www.livinglandsandwaters.org/.