Plastic Pollution on Human Health

Plastic Pollution on Human Health

 What are microplastics?

The Dhali Lama once said something along the lines of ‘if you think something small can’t make a big difference, try sleeping in the same room as a mosquito’. I love this quote, but now sadly, I have another analogy: if you think something small can’t have a big impact, just take a look at microplastics.

I’m a baby boomer so the word microplastics was introduced to me in my 40s, but sadly for Gen Z and beyond it has been with them since birth (quite literally: did you know that microplastics have now been found in human placentas?)

The definition of a microplastic is a piece of plastic below 5mm in size. Microplastics come in all different shapes, they can be fibres, foam, fragments or beads.

Most are invisible to the naked eye, are present in our houses, seas and fields.

Our seas especially are full of microplastics. They have been found in the Marianna trench – the deepest area of sea in the world. Closer to home they have been found in human blood, faeces, and maternal breast milk. The animals and vegetables that we eat contain them and filter feeders such as mussels having a higher concentration of them than other animal products.

We are discovering how they affect human health; We thought initially that they were inert pieces of material that either went through our bodies or just sat in our bodies, but there is now growing evidence that they interact with our bodies causing ill health. Inhaling may be as harmful as ingestion.

 Recent research in the University of Hull found microplastics in the deepest sections of human lungs, the authors said this was worrying because the plastic was not being filtered out or trapped. In 2021-22 over 400 scientific articles were published about microplastics and their potential harm to human health.

However, what we don’t know yet is the long-term side effects of having them within us, whether they have a cumulative effect and if there is a cut off amount where they start to become harmful. Obviously the younger you are then the longer it’s within you.

Where do microplastics come from?

If something is biodegradable it can be decomposed by bacteria or other living organisms. But plastic isn’t biodegradable and when it breaks up it just becomes smaller but remains as plastic. Plastic bottles when they eventually break up become smaller pieces of plastic. Recycling is a partial answer, however you can only recycle plastic 4 or 5 times before it becomes impossible to use. It then is headed of landfill or worse, finds its way into our oceans, where it may break down – but only into microplastics, out of sight doesn’t mean it’s not there. 

There are other ways that microplastics come into being.

 According to the Plastic Soup Foundation, synthetic fibres are the largest source of microplastics in our oceans. Research in 2017 research revealed as much as 35% of marine microfibres come from synthetic textiles. Five kg of synthetic clothing releases an average of nine million microfibres that are carried down the drain with the rinse water.  Currently nearly 70% of all clothing is already made from some form of plastic such as polyester, nylon, acrylic or polyamide. Who can investigate their wardrobe and not see some synthetic fibres? Fast fashion has a lot to blame, some clothes manufactured to last for a few washes only before they become either misshaped or ‘out of fashion’. New synthetic fibres are then made for the next fashion season.

Other ‘unseen’ contributors to microplastics include cosmetics, a recent report by the Plastic Soup Foundation stated that nine out of 10 cosmetics products from leading brands contain microplastic particles, these included sunscreen, shampoos, lipsticks, deodorants, and moisturisers. The government banned the use of plastic microbeads in rinse off cosmetics in 2018 –so what is in these cosmetics aren’t plastic microbeads, but other types of plastic.

What does the microplastics do in our seas?

Microplastics are unseen in our oceans, it’s not the images of huge plastic islands, but literally a sea of unseen particles floating through our aquatic world.  

Marine microplastics concentrate in two places, firstly the 5 huge ocean currents called gyres which flow around the world. These gyres act like giant whirlpools in which floating waste is slowly sucked into the middle, a bit like water down the drain. All 5 of these gyres have increased concentration of microplastics compared to other parts of the ocean.

But even more concentrated than the gyres are ‘hot spots’,

For those of you heading to the Mediterranean Sea this summer, then sadly I must tell you that it is one such hot spot. There is a continuous supply of plastic from rivers flowing into the Mediterranean and from coastal cities. On the other hand, the exit out into the Atlantic Ocean is so narrow that little plastic escapes increasing the concentration of microplastics within the Mediterranean Sea.

So what can you do?

Well, let’s be positive. The problem is being flagged and it is on people’s radars. The charity Plastic Soup Foundation has many resources and information that you may wish to check out including some innovative alternatives to plastic.

Personally, I have been already using ‘keep cups’, my own recycled shopping bags, carrying my water in my own bottle and having milk delivered in glass bottles.

But the eye opener for me is my clothing.

It’s a personal (and financial) choice whether you wish to recycle all your synthetic clothes and buy new clothes in cotton, wool and silk.

A bit expensive for most I imagine and arguably wasteful. But moving forward, thinking about buying clothes that will last, that aren’t just for one season and have at least more natural fibres in them than synthetic is something that we can all do. Pressure also needs to be put on the fashion industry; they need to be in a position where they can remain commercially viable without constantly having to produce cheap synthetic clothing. A level playing field needs to be made – usually by legislation.


Finally, I read in the ‘journal of Hazardous Materials’* that models predict mussels sited at the mouths of estuaries could remove 4% of microplastics emanating from nearby rivers. This is a great nature-based solution – but it does make you think about the poor mussels – destined to filter and poop our plastic. Rather than harnessing mussels, can’t we just manufacture less?


* Journal of Hazardous Materials 

Volume 453, 5 July 2023, 131392

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