Examination of the ocean as a source for atmospheric microplastics

• Published in: PloS one Vol. 15; no. 5; p. e0232746
• Main Authors: Allen, Steve, Allen, Deonie, Moss, Kerry, Le Roux, Gaël, Phoenix, Vernon R, Sonke, Jeroen E
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 12.05.2020; Public Library of Science (PLoS)
• Subjects: Aerodynamics; Air pollution; Air sampling; Algae; Analysis; Atmosphere; Atmosphere - chemistry; Bacteria; Biota; Boundary layers; Bubble bursting; Earth Sciences; Ecology and Environmental Sciences; Environmental aspects; Environmental engineering; Environmental Sciences; Europe; Marine environment; Microplastics; Microplastics - analysis; Ocean bottom; Ocean currents; Ocean floor; Ocean-atmosphere interaction; Oceans; Oceans and Seas; Physical Sciences; Pilot Projects; Plastic pollution; Plastic products; Plastics; Plastics industry; Pollutants; Pollution; Polymers; Public health; Sea breezes; Sea currents; Sea spray; Sea states; Seawater - chemistry; Sediments (Geology); Strong winds; Sustainability; Turbulence; Viruses; Water Pollutants, Chemical - analysis; Water pollution; Wave action; Wave propagation; Wind; Europe; United Kingdom > UK; France
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0232746

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.