Atmospheric deposition of microfibers
Brett Roblin1 and Julian Aherne2
Plastics particles < 5 mm long called microplastics, have been found throughout marine, freshwater and terrestrial systems. There is growing concern of their environmental impacts given that they can absorb organic pollutants and trace metals. While our understanding of the sources and transport of microplastics has increased during the last decade, there have been limited studies on microplastics in atmospheric deposition. In this study, rainfall was collected from four ‘background’ precipitation chemistry stations under the EMEP network from June 2017 to May 2018. Daily rainfall samples were bulked by calendar month and analyzed for microfibers. Samples were vacuum filtered on to GF/C Whatman filters and microfibers were identified and counted using a stereomicroscope. Pictures each of microfibers were taken and measured using image processing software. A subsample of microplastics were further analyzed using Raman spectroscopy to identify the type of plastics. Annual deposition ranged from 16 to 29 microfibers per litre, resulting in a deposition of 64.5 to 102.0 microplastics/m2/day. The average microfibre length was 1.28 mm, resulting in a deposition of 37.6 m of microplastics/m2. Atmospheric deposition is an important vector for the transport of microfibres into remote locations.
1Trent University, brettroblin@trentu.ca 2Trent University, jaherne@trentu.ca