Micro-Plastic Is Blowing in the Wind, Climbing the Food Chain

The discovery of microplastics in the air above the ocean reveals the spread of this hazardous pollution

As the plastic in our oceans breaks up into smaller and smaller bits without breaking down chemically, the resulting microplastics are becoming a serious ecological problem. A new study at the Weizmann Institute of Science reveals a troubling aspect of microplastics – defined as particles smaller than 5 mm across. They are swept up into the atmosphere and carried on the wind to far-flung parts of the ocean, including those that appear to be clear. Analysis reveals that such minuscule fragments can stay airborne for hours or days, spreading the potential to harm the marine environment and, by climbing up the food chain, to affect human health.

“A handful of studies have found microplastics in the atmosphere right above the water near shorelines,” says Dr. Miri Trainic, in the groups of Prof. Ilan Koren, of the Institute’s Earth and Planetary Sciences Department and Prof. Assaf Vardi of the Institute’s Plant and Environmental Sciences Department. “But we were surprised to find a non-trivial amount above seemingly pristine water.”

Koren, Vardi and Prof. Yinon Rudich of the Institute’s Earth and Planetary Sciences Department have been collaborating for a number of years on studies designed to understand the interface between ocean and air. While the way the oceans absorb materials from the atmosphere has been well studied, the opposite-direction’s process – aerosolization, in which volatiles, viruses, algal fragments and other particles are swept from seawater into the atmosphere – had been much less investigated.

As part of this ongoing effort, aerosol samples were collected for study in the Weizmann labs during the 2016 run of the Tara research vessel, a schooner on which several international research teams at a time come together to study the effects of climate change, primarily on marine biodiversity. The Weizmann team affixed the inlet of their measuring equipment to the top of one of the Tara’s masts (so as to avoid any aerosols produced by the schooner, itself) and Dr. J. Michel Flores, of Koren’s group, joined the mission to tend to the collecting as the schooner sailed across the North Atlantic Ocean.

The research setup included an intake at the top of the mast. The Tara research schooner, 2016.