Microplastics: All Up in the Air?

It is often said that plastics, and particularly microplastics (<5mm), are allaround us, especially in the oceans where there is much concern about possible harmfuleffects on marine life.  The route of entry for plastics to the marine environment is generallyseen to be via rivers acting as a conduit after their production on the land by a whole host ofprocesses and uses by our societies.   But in all the discussion on thetopic and rapidly growing research activity, the atmosphere barely gets a mention.  But, recently published results show significant amounts of microplasticsin air at a remote terrestrial location in the Pyrenees (Allen et al., 2019, Nature Geoscience12:339).  However, there appear to be no results from measurements over the oceans.   Ifthese results from the Pyrenees are representative of the marine atmosphere a simplecalculation indicates a significant atmospheric route for the distribution of microplastics andtheir subsequent deposition to the oceans.  If correct such a pathway would lead to thedistribution of microplastics wider and faster than by ocean circulation alone.  It would alsomore readily explain why microplastics have been reported recently in Arctic snow(Bergmann et al., 2019, Sci. Adv. 5: eaax1157).  In addition, it would also lead to a reframingof our understanding of the budget and distribution of microplastics globally.