Examination of the ocean as a source for atmospheric microplastics

PLoS One. 2020 May 12;15(5):e0232746. doi: 10.1371/journal.pone.0232746. eCollection 2020.

Abstract

Global plastic litter pollution has been increasing alongside demand since plastic products gained commercial popularity in the 1930's. Current plastic pollutant research has generally assumed that once plastics enter the ocean they are there to stay, retained permanently within the ocean currents, biota or sediment until eventual deposition on the sea floor or become washed up onto the beach. In contrast to this, we suggest it appears that some plastic particles could be leaving the sea and entering the atmosphere along with sea salt, bacteria, virus' and algae. This occurs via the process of bubble burst ejection and wave action, for example from strong wind or sea state turbulence. In this manuscript we review evidence from the existing literature which is relevant to this theory and follow this with a pilot study which analyses microplastics (MP) in sea spray. Here we show first evidence of MP particles, analysed by μRaman, in marine boundary layer air samples on the French Atlantic coast during both onshore (average of 2.9MP/m3) and offshore (average of 9.6MP/m3) winds. Notably, during sampling, the convergence of sea breeze meant our samples were dominated by sea spray, increasing our capacity to sample MPs if they were released from the sea. Our results indicate a potential for MPs to be released from the marine environment into the atmosphere by sea-spray giving a globally extrapolated figure of 136000 ton/yr blowing on shore.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Atmosphere / chemistry*
  • Microplastics / analysis*
  • Oceans and Seas*
  • Pilot Projects
  • Seawater / chemistry
  • Water Pollutants, Chemical / analysis*

Substances

  • Microplastics
  • Water Pollutants, Chemical

Grants and funding

The data has been funded by GET and WESP (University of Strathclyde) research department support. The research leading to these results has also received funding from the People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme (FP7/2007-2013) under REA grant agreement n. PCOFUND-GA-2013-609102, through the PRESTIGE programme coordinated by Campus France. The research has been supported by the CNRS TRAM Project, ANR-15-CE01-0008, Observatoire Homme-Milieu Pyrénées Haut Vicdessos - LABEX DRIIHM ANR-11-LABX0010, and by and the H2020 ERA-PLANET (689443) iGOSP programme. This research was also supported by the Leverhulme Trust Early Careers Fellowship Grant ‘Looking back for the future through archives of Airborne Microplastic Pollution’, grant number ECF-2019-306.