Microplastics - Should You Be Concerned?

Microplastics are defined as pieces of plastic equal to or smaller than 5mm(1). These plastics have either been made this way, such as those found in exfoliating skincare products and toothpastes (although these were banned in the UK in 2018), or they break down from larger pieces. All plastics will break down into smaller and smaller pieces once they have been discarded, so banning those products certainly hasn’t solved this issue and don't forget the microplastics released into the environment prior to this will never disappear.

In 1950, 2 million tons of plastic were produced globally and by 2018 this had increased to 380 million tons. If things continue as they are, it’s expected by 2050 we will see 12 billion tons of plastic in landfill and our oceans(2). Of the 8.3 billion metric tons of plastic that has ever been produced, 6.3 billion metric tons have become waste, of which only 9% has been recycled and 12% incinerated(2). I don’t know about you but I find these numbers so overwhelmingly enormous it’s impossible to envisage the scale of the problem, other than knowing that it’s a HUGE one! So here’s an image of part of the Great Pacific Garbage Patch, the largest of five enormous patches of discarded plastic found floating in the ocean. It spans approximately 1.6 million square kilometres, which is around 3 times the size of France!!

But don’t think it ends with the plastic simply sitting there – the ocean’s currents, sunlight and maritime winds ensure the plastic is continuously swirling around and crashing together. The stuff doesn’t biodegrade as it’s not a natural material, so these actions it just break it down into smaller and smaller pieces.

The really scary part is that the smaller the pieces are, the harder it is to capture and clean up. The smaller it gets, the easier it is for marine life to ingest it. Larger birds and animals such as seagulls, seals and whales can eat larger pieces or particles of plastics, or can get caught up in it causing injury and/or death. And very tiny sea-dwellers, such as prawns, mussels, and even zooplankton, can ingest the really minute pieces of plastic (3). The plastic has nowhere to go as it doesn’t break down, so it’s what is known as a ‘bio-accumulator’. This means that as it works its way up the food chain, its quantity increases. For example, zooplankton will ingest teeny tiny particles during feeding and filtration (4). The fish that feed on them will then eat hundreds or thousands of them, each with plastic particles inside, and they’ll likely ingest microplastics themselves from breathing and filtering the water too. And so it continues up the chain, multiples of those fish and shellfish being eaten by dolphins/sharks/whales – and us.

                                                                                   Microplastics on finger tip

Studies have shown the presence of microplastics in human stool (5), providing evidence that it has made its way into our food chain. This is likely via food and water consumption – the WHO published a report last year examining  microplastic contamination of our water supplies too. And if you’re thinking of switching to bottled water think again, it’s even worse there due to the plastic containers it comes in and the microplastics they shed (6). But it’s not all doom and gloom, the WHO have stated that there is currently no known risk to human health, although more research is urgently needed as this hasn’t been investigated extensively enough. The UKWIR also found that our water boards do a pretty good job of filtering most of it out, 99.9% in fact(7), and using another filter at home will help too.

So far we've mostly discussed the presence of microplastics in water and marine life but it’s by no means restricted to these regions. Microplastics have been found EVERYWHERE, from an uninhabited island in the South Pacific(8) to the the snow-capped peaks of Everest(9) - there is absolutely no escaping it. It breaks down into such small pieces that it can travel on the wind and in rain(10). It’s been shown that we can breathe in plastic particles smaller than 25nm and those 5nm or less have been found embedded in human lung tissue(11). It’s also been shown that microplastics can act as vectors to carry contaminants, including heavy metals, bacteria and other organic pollutants(12), and more research is urgently needed to understand what risks this carries too. And I haven’t even mentioned the presence of microplastics in soil(13)and the effects this could have on plant ecosystems and agriculture.

So perhaps we need to think twice the next time we reach for that packet of single-use-plastic-housed pasta or rice when we next visit our supermarkets, and opt for the loose fruit and veg over plastic-wrapped versions. It may provide a moment of convenience for us but it leaves several lifetimes of detrimental environmental and health implications. Much more research is needed into the effects of microplastics on our health but I feel pretty confident in saying: it doesn't look good.


  1. GESAMP (2015). Sources, fate and effects of microplastics in the marine environment: a global assessment. (P. J. Kershaw, ed.). (IMO/FAO/UNESCO-IOC/UNIDO/WMO/IAEA/UN/UNEP/UNDP Joint Group of Experts on and t. S. A. o. M. E. Protection). Rep. Stud. GESAMP No. 90: 96 pp
  2. Production, use and fate of all plastics ever made. Geyer, R., Jambeck, J.R. and Law, K.L., Science Advances, 19 Jul 2017: E1700782
  3. Smith M, Love DC, Rochman CM, Neff RA. Microplastics in Seafood and the Implications for Human Health. Curr Environ Health Rep. 2018;5(3):375-386. doi:10.1007/s40572-018-0206-z
  4. Sun X, Liang J, Zhu M, Zhao Y, Zhang B. Microplastics in seawater and zooplankton from the Yellow Sea. Environ Pollut. 2018;242(Pt A):585-595. doi:10.1016/j.envpol.2018.07.014
  5. Schwabl P, Köppel S, Königshofer P, et al. Detection of Various Microplastics in Human Stool: A Prospective Case Series. Ann Intern Med. 2019;171(7):453-457. doi:10.7326/M19-0618
  6. Oßmann BE, Sarau G, Holtmannspötter H, Pischetsrieder M, Christiansen SH, Dicke W. Small-sized microplastics and pigmented particles in bottled mineral water. Water Res. 2018;141:307-316
  7. UKWIR (2019) Skin To River, River To Tap: A Review of Potential Risks from Nanoparticles and Microplastics. Ball, H. et al. Report Ref No. 19/EQ/01/18
  8. Significant anthropogenic debris on remote island. Jennifer L. Lavers, Alexander L. Bond. Proceedings of the National Academy of Sciences. Jun. 2017, 114 (23) 6052-6055; DOI:10.1073/pnas.1619818114
  9. Ajith, N., Arumugam, S., Parthasarathy, S. et al.Global distribution of microplastics and its impact on marine environment—a review. Environ Sci Pollut Res27, 25970–25986 (2020).
  10. Allen, S., Allen, D., Phoenix, V.R. et al.Atmospheric transport and deposition of microplastics in a remote mountain catchment. Nat. Geosci.12, 339–344 (2019)
  11. Pauly JL, Stegmeier SJ, Allaart HA, et al. Inhaled cellulosic and plastic fibers found in human lung tissue. Cancer Epidemiol Biomarkers Prev. 1998;7(5):419-428
  12. Caruso G. Microplastics as vectors of contaminants. Mar Pollut Bull. 2019;146:921-924. doi:10.1016/j.marpolbul.2019.07.052
  13. de Souza Machado AA, Lau CW, Kloas W, et al. Microplastics Can Change Soil Properties and Affect Plant Performance. Environ Sci Technol. 2019;53(10):6044-6052

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