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Microplastics are harmful to humans

There is growing concern about effects marine microplastics may have on people, including toxic chemicals leaching from plastic litter and the fact that “microscopic particles are making their way into the food chain and affecting human health. But are they harmful?”[1]

It appears that the marine food web is full of plastic. It has been found in the stomachs of deep sea fish in the Northwest Atlantic,[2]in fish in the English Channel,[3]in endangered sea turtles,[4],[5]in giant Bluefin tuna off the coast of Lebanon[6]and in the stomach of a whale that died off the coast of Norway in 2017.[7]Concerns include that when ingested, microplastics can affect the feeding behaviours of marine animals and cause weight-loss. Another fear is that when smaller fish are eaten by predators like tuna and swordfish, the plastic moves up the food chain. Chemical pollutants can also bind to microplastics and may increase accumulations of toxins in larger predatory fish – and so particles and toxins can end up on our plates. Such toxins could pass through cell membranes, potentially increasing exposure to harmful chemicals.

However, assessing the risks to human health from marine plastic is complex and there is still much we do not know about its potential to affect human health.[8]In addition, “the uptake of plastic-associated chemicals in humans due to inadvertent ingestion of microplastics in seafood appears likely to be no more significant than other human exposure pathways of these chemicals.”[9]

So, while there is growing concern about the effects microplastics may have on humans, and while the knowledge gap on this subject is narrowing, further work is needed to establish its effects on our health.

[1] UNEP and GRID-Arendal, 2016. Marine Litter Vital Graphics. United Nations Environment Programme and GRID-Arendal. Nairobi and Arendal.,
[2] Wieczorek, A.M. et al. , 2018. “Frequency of Microplastics in Mesopelagic Fishes from the Northwest Atlantic.” Frontiers in Marine Science, February 19, 2018,
[3] Lusher, A.L. et ., 2013. Occurrence of microplastics in the gastrointestinal tract of pelagic and demersal fish from the English Channel. Marine Pollution Bulletin. Volume 67, Issues 1–2, 15 February 2013, Pages 94-99.
[4] Lutz, P.L., 1990. Studies on the ingestion of plastic and latex by sea turtles. In: Shomura, R.S., Yoshida, H.O. (Eds.), Proceedings of the Workshop on the Fate and Impact of Marine Debris. National Oceanic and Atmospheric Administration Technical Memorandum Honolulu, Hawaii (154 pp.). Available here
[5] Caron, al., 2018. Ingestion of microplastic debris by green sea turtles (Chelonia mydas) in the Great Barrier Reef: Validation of a sequential extraction protocol. Marine Pollution Bulletin.
Volume 127, February 2018, Pages 743-751.
[6] Plastic found in belly of tuna highlights waste problem – 
[7] Zoologists say dead whale in Norway full of plastic bags –
[8] UNEP and GRID-Arendal, 2016. Marine Litter Vital Graphics. United Nations Environment Programme and GRID-Arendal. Nairobi and Arendal.,
[9] UNEP, 2016. Marine plastic debris and microplastics – Global lessons and research to inspire action and guide policy change. United Nations Environment Programme, Nairobi

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