April 15, 2019

expert reaction to atmospheric transport of microplastics

Research published in Nature Geoscience suggests that microplastics can reach and affect remote areas through atmospheric transport.

Dr Ben Williams, Research Fellow at the Air Quality Management Resource Centre, University of the West of England, said:

“This research helps build a picture of microplastic presence within a specific environment. The conclusions are backed up by solid data using the most up to date analytical tools for the characterisation of microplastics. It would be interesting to measure the daily deposition rate of microplastics at the same location, in order to further define the key transport routes and whether certain types of microplastics are deposited during specific periods.

“It is unsurprising that microplastics travel through the atmosphere. There is still very little evidence of airborne microplastics, not because they’re not in the air, but it hasn’t been studied extensively. We only have to lift our head from the paper and look around us to see plastic everywhere. We wear it, we drink from it, we make furniture from it, it is everywhere. We need to understand our contribution to the environment, whether that’s understanding the sources of microplastics we find in the oceans or microplastics we find in our air, soil and water.

“Microplastics in the environment will be present in many forms. For example, they’ll likely be different sizes, shapes, age, have been exposed to different weathering patterns and chemical additives. As a consequence it’s very difficult to determine the effect of microplastics on a particular ecosystem without first understanding what the properties of the microplastic in question are. We need to develop robust characterisation approaches to identify the specific sources of airborne microplastics, find the most appropriate means of managing them and in doing so we can help reduce any potential impact on our environment.”

Dr Stephanie Wright, Research Fellow, MRC-PHE Centre for Environment and Health, King’s College London, said:

‘We know microplastics deposit out of the atmosphere in megacities. This has not previously been shown for a pristine environment, however, it is unsurprising given their low density and diffuse nature. The back-trajectory findings (where the material has come from) should, however, be inferred with caution due to the small sample size. Moreover, since we know very little of the source emissions of microplastics to the atmosphere, it is difficult to conclude exactly how far they have travelled.

“These findings do suggest that microplastics are omnipresent and even the most pristine environments may be susceptible to contamination. Microplastics are persistent, and hence will accumulate in the environment over time, unless emissions are reduced. Long-term ecological consequences are unknown, but more work is needed to understand microplastic sources and dispersion and hence susceptible habitats and populations.”

Alice Horton, Ecotoxicologist at the Centre for Ecology and Hydrology, said:

“It is not surprising that microplastics have been found in this remote region, as research to date has shown that microplastics are ubiquitous worldwide.

“Microplastics commonly shed from items while in use, for example clothing, tyres and machinery, and often end up far from the source. While we know that microplastics can be mobilised and transported by a range of environmental processes, these processes are not yet well-understood.

“This study is the first to provide concrete evidence of microplastics transported to remote regions by air, and therefore enhances our understanding of the ways in which microplastics can be widely transported around the globe. 

“Concentrations found in this study were comparable to those found within urban areas which highlights that with respect to microplastics, many remote areas may not be as pristine as assumed, a fact which warrants further research.”

Dr Stefan Reis, Head of Atmospheric Chemistry and Effects, Centre for Ecology and Hydrology (CEH), said:

“The findings of this study illustrate a potential ‘missing link’ in the way microplastics are dispersed in the environment. The results of this rigorous analysis show that atmospheric deposition of microplastics does not only occur in urban areas, near known sources, but at remote, rural sites as well. A next step, following on from this preliminary study, needs to be a comprehensive atmospheric transport modelling of how the material travels from source to deposition. To do this understanding the source of the microplastics will be paramount, as the authors indicate. Here, the analysis of the type of microplastics documented in the paper will add vital information to the identification of potential major sources of release into the atmosphere. With the focus of research on plastics polluting oceans¹ and waterways, the results presented indicate contributions through airborne transport, potentially from source regions tens or thousands of kilometres away, which are so far largely unaccounted for. This highlights an urgent need to quantify the key emission sources of such microplastics, for instance from spreading of sewage sludge on agricultural soils², and the mechanisms of their dispersion, in order to enable robust modelling of the atmospheric distribution pathways and environmental fate.”

¹ DOI 10.1038/s41598-017-11079-2https://www.nature.com/articles/s41598-017-11079-2

² DOI: 10.1021/acs.est.6b04140 https://pubs.acs.org/doi/pdf/10.1021/acs.est.6b04140

‘Atmospheric transport and deposition of microplastics in a remote mountain catchment’ by name of first author et al. was published in Nature Geoscience at 16:00 UK time on Monday 15th April.

Declared interests

Dr Ben Williams:

Member of the WHO Collaborating Centre for Healthy Urban Environments

Committee Member of the International Network of Environmental Forensics

International Scientific Advisory Committee for the Wessex Institute Air Pollution Conference Series

Member of the Institute of Air Quality Management

Member of the Institution of Environmental Sciences

Dr Stephanie Wright :

Paid Employment:

Research Support (grants):

Other:

Alice Horton: No declarations of interest.

Dr Stefan Reis : No conflict of interests declared.