Microplastics in our homes

Dr Fay Couceiro, Reader in Biogeochemistry and Environmental Pollution in the School of Civil Engineering and Surveying, explains what microplastics are present in our homes, where they come from and what we can do to minimise their impact on our health.

A lot of research has taken place examining the occurrence and impact of microplastics in the external environment, such as plastics in the oceans and litter in the natural environment. 

Dr Fay Couceiro’s latest research brings the subject closer to home. Inside our homes, in fact. 

What are microplastic fibres?

As plastics break down or shed from man-made materials, they break down into smaller and smaller pieces, known as microplastics.

Microplastics are defined as any plastic below 5mm in size. Some are even smaller and invisible to the naked eye. Airborne microplastics, for example, are 1/70th of the width of the average human hair and we can inadvertently breathe them into our lungs.

There is very little data available about microplastics indoors so, as part of Revolution Plastics, we’re measuring microplastics in different indoor environments – looking at the type, size and shape of the plastics found. 

While more research is needed, studies have already shown that the concentration of microplastics indoors can regularly be 60 times higher than outdoors. 

Is it dangerous to breathe in microplastics?

Professor Anoop Jivan Chauhan MBE, Respiratory Specialist and Director of Research and Innovation at Portsmouth Hospitals University NHS Trust, was shocked by the results. The levels of microplastics in the air in this study are 100 times higher than any other academic research has previously predicted.

Aside from the environmental damage caused by plastics, there is growing concern about what inhaling and ingesting microplastics is doing to our bodies. We intend to conduct further research at the University of Portsmouth to discover more about how microplastics enter the human body and what their impact might be on our health.

For example, we’re working with Portsmouth Hospitals University NHS Trust to investigate the presence of microplastics in the lungs of chronic obstructive pulmonary disease (COPD) and asthma patients. The research may alert patients of risks or triggers for their condition, such as recently carpeted or hoovered rooms that may have a high number of fibres in the air.

It all comes out in the wash

In a follow up study with GMB, available to watch here, we investigated what happens when we wash synthetic clothes. 

We collected the wastewater from a washing machine so we could see how many fibres would have otherwise travelled into the sewer. This resulted in a visible pile of fibres. If every household in the UK did two washes like this a week, it would add up to the equivalent of over 20 million pairs of socks being washed down our drains every year.

There’s an implication for human health too. 90% of the microplastics in sewage end up in the sludge, which is used as fertiliser on agricultural land and can therefore end up in the food chain.

Plastic filters for washing machines

The issue of microplastic fibres being shed from our clothes during washing was raised in a bill in UK Parliament in 2021.

Alberto Costa MP is pushing for the UK government to follow in the footsteps of France, which has legislated for all new washing machines to have microplastic fibre filters fitted by 2025. The filters capture such fibres and prevent them from entering water streams.

How can microplastics be detected?

Some microfibres, like those in the washing wastewater, could be detected with the naked eye, but what about tiny microplastics?

To identify these in the University lab, we use a special microscope called a micro-Raman, which can reveal tiny pieces of plastic below 1 micrometre in size and determine their polymer type. 

This enhances our research as we’re able to identify microplastics in the air and potentially those with the ability to enter the bloodstream. Only a handful of UK universities have this specialist equipment.

More recently we purchased a one-of-a-kind mega laser, which can rapidly analyse the chemical composition of plastics, metals and even dust. The femtosecond laser ablation (LA) and laser induced breakdown spectroscopy (LIBS) system – installed at the University of Portsmouth in 2021 – is the only one of its kind at any university in the UK or Europe. Among other uses, it will help us to understand how microplastics may harm human health.

This takes place within our Microplastics Research Group, which takes a holistic, interdisciplinary look at microplastics. We’re studying their impact in all environments — including soil, air, water — and their impacts on plant, animal and human health. Most importantly our research is focussed on identifying solutions to limit the impact of microplastics.