Microplastics are usually pictured as fragments of things that were obviously plastic: a bottle worn down, a bag torn apart by the sea.

The UN Environment Programme names three everyday sources. Two of them are not called plastic by anyone.

The key point

“Microplastics known as cellulose acetate fibres comprise the majority of cigarette filters.” Cigarette butts are the most common plastic litter on beaches.

Clothing is the second: plastics are about 60% of all clothing material, and it sheds “when washed or worn”.

The third is cosmetics. None of the three looks like a plastic object.

Cigarette filtersThe one on every beach

A filter looks like compressed paper or cotton. It is neither.

6 trillion
cigarettes consumed annually, by one billion smokers.
UNEP, 28 April 2023
No. 1
cigarette butts are the most common plastic litter on beaches.
UNEP, 28 April 2023
≤ 5mm
the size below which a plastic particle counts as a microplastic.
UNEP, 28 April 2023

And they do not simply sit there. UNEP: when they break down, cigarettes release microplastics, heavy metals and many other chemicals. The filter was designed to trap things, it keeps them, then releases them somewhere else.

TextilesThe one that keeps shedding

One detail here is easy to miss, and it changes what the fix would be.

Washed or worn

“Due to abrasion, clothing and textiles with these materials shed microplastics known as microfibres when washed or worn.”

Around 9% of annual microplastic losses to the ocean come from clothes and other textiles, per a 2020 UNEP report on the global textile value chain. And laundry alone releases around 500,000 tonnes of plastic microfibres a year, “the equivalent of almost 3 billion polyester shirts”.

Which connects the three articles of this series into one line: the emissions happen when the plastic is made, the sector it comes from is usually not the one we picture, and the object keeps releasing plastic for as long as it is used.

EvidenceWhat is known, and what is not

This is where most articles on microplastics stop being careful. So here is the order the source itself puts things in.

  • Presence is established. “Microplastics have been found in various human organs, and even in the placenta of newborn babies.”
  • The 2021 report speaks of association. Chemicals in microplastics “are associated with serious health impacts, especially in women”the word is associated, and it is worth keeping.
  • UNEP states the limit itself. Its Head of the Marine and Freshwater Branch: the impacts of hazardous chemicals and microplastics on human and marine physiology “is still nascent and must be prioritized and accelerated”.

Why the distinction is not a detail. “Found in an organ” and “causes a disease” are two different statements, and only the first is established here. The same UNEP official draws the practical conclusion without overstating the science: “action limiting their spread and prevalence will undoubtedly be beneficial to our long-term health.”

RecommendationsWhat UNEP's people actually recommend

Two of them, and the second comes with a caveat the source attaches itself, which is why it is worth reading in full rather than in a headline.

  • Re-wear clothes more often and wash them less often. That is the whole recommendation, and it costs nothing.
  • When buying, sustainably sourced natural materials“though doing so may come with other environmental trade-offs”. UNEP writes the caveat in the same sentence as the advice.

That second caveat is the honest shape of the whole subject. There is no material that is free of everything, and the source that tells you so in the same breath as its own advice is the one worth trusting.

QuestionsFrequently asked questions

Does a cigarette filter contain plastic?

It is made of it. UNEP writes that “microplastics known as cellulose acetate fibres comprise the majority of cigarette filters”. These are not added particles: it is the filter material itself.

What is a microplastic?

A very small plastic particle, UNEP writes “up to 5mm in length” in English, “jusqu'à cinq millimètres de diamètre” in French. It is not a separate substance: it is plastic that got small, either made that way or through breakdown and abrasion.

What is the most common plastic litter on beaches?

Cigarette butts. UNEP states it plainly and links it to volume: six trillion cigarettes are consumed annually by one billion smokers, which means these fibres “reach every corner of the world”.

What share of microplastics comes from clothing?

Around 9 per cent of annual microplastic losses to the ocean, according to a 2020 UNEP report mapping the global textile value chain. Clothes shed them “when washed or worn”, not only in the wash.

Do we know what microplastics do to human health?

Not yet, and it is UNEP that says so. The Head of its Marine and Freshwater Branch writes that the impacts of hazardous chemicals and microplastics on human physiology “is still nascent”. The 2021 report uses the word “associated”, not “cause”. What is established is presence: they have been found in various human organs.

What do UNEP's experts recommend?

For textiles: re-wear clothes more often and wash them less often. And when buying, sustainably sourced natural materials, with UNEP itself adding that “doing so may come with other environmental trade-offs”. The caveat is part of the recommendation.

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