With microplastics reaching far and wide, mosses’ ability to capture atmospheric particles means they can be studied to assess the extent and amount of pollution. Dr Richard Cross, an ecotoxicologist at the UK Centre for Ecology & Hydrology, discusses the findings and relevance of a UK-wide survey…
Moss has been used for over 30 years to track and trace pollution in the environment under the Convention on Long-range Transboundary Air Pollution.
Take a look around you on your next walk and you’ll see why. Unassuming, and often overlooked, moss can be found almost everywhere. Its ability to sit and capture chemicals and particles from the air, while not drawing up material from the soil beneath makes it, in effect, a natural log-book of atmospheric pollutants in the recent past.
And now it is being put to use to establish whether microplastics borne on the wind are depositing across our countryside. Work in the International Cooperative Programme on Effects of Air Pollution on Natural Vegetation and Crops, has piloted methods to monitor tiny plastic fibres in moss. Our new research at the UK Centre for Ecology & Hydrology extends the ability of this method to look at ever-smaller microplastic fragments, using infra-red microscopy, analysed at the UKCEH Microplastics Analysis Facility.
Monitoring moss from 52 sites across the UK, our new study represents the first national scale survey of its kind, looking at microplastics contamination of rural mosses across the UK. We found almost ubiquitous presence of microplastics in these mosses. This suggests that diffuse atmospheric sources such as the wear and tear of plastics occurring daily, all around us, may play a role in this widespread prevalence in rural areas.
Tracking plastics
Concentrations ranged from less than a single particle to close to 25 microplastic fragments per gram of moss. While it is difficult to assess the risk that these microplastics trapped from the air in moss pose to wildlife, there is concern that without a reduction in the production and emission of plastic waste into the environment, safe levels will be exceeded in the future.
Global plastic production now exceeds 400 million tonnes annually and is set to almost triple by 2060.
Plastic waste will continue to disintegrate into ever smaller fragments but an ever-increasing supply of waste will feed this cycle. It is therefore essential to track how microplastics are accumulating in the environment in the coming years.
Surveys such as the present study provide a baseline from which such longer-term trends can be monitored. If repeated in the future, we can begin to shine a light on changing patterns over time.
There is momentum to reach a legally binding agreement on plastics, for example through the ongoing United Nations Environment Programme negotiations for a Global Plastics Treaty. Any agreement that comes out of this process will need to be monitored, and the success of any policy change could be traced by the shifting signal we may observe in monitoring programmes such as the moss survey.
In this way, by establishing the methods to monitor microplastics, we can begin to understand how societal or policy changes in how we live with and deal with microplastics, play out in the real world.
Paper information
Cross et al. 2026. Monitoring moss reveals widespread deposition of airborne microplastics across the UK. Microplastics and Nanoplastics. DOI: 10.1186/s43591-026-00191-8. Open access.
The work was funded by Defra Contract AQ0846, ICP Vegetation as part of the project ‘The UK survey of mosses for metals, nitrogen and microplastics, 2020-2022’.