MONTREAL — Hurricane Larry dropped millions of microplastic particles over Newfoundland and Labrador during its passage in 2021 — microplastics that all came from the Atlantic Ocean, Dalhousie University researchers found.
“Sometimes they say it’s pouring rain,” said Professor Tony Walker. We can now say that it is raining ropes and microplastics.”
Larry's arrival presented researchers with a unique opportunity not to be missed, as the hurricane never made landfall between its birth off the west coast of Africa and its arrival in Canada.
On the other hand, he flew over the Garbage Patch of the North Atlantic, where thousands of tons of garbage accumulate. It was therefore clear that all of these microplastics, if any, would come from the Atlantic Ocean.
Once the storm's path was clear, two students, Anna Ryan and Amber LeBlanc, hastily organized to collect Larry's rain in a cylindrical glass container (to avoid any risk of contamination).
The hurricane made landfall near Great Bona Cove on September 11, 2021, as a Category 1 hurricane with winds of 80 mph and gusts in excess of 110 mph.
The researchers collected samples between September 9th and 12th. A new sample was taken every six hours, for a total of eleven samples.
The cylinder installed by the two researchers collected an average of around 20,000 microplastic particles per square meter per day before and after Larry's visit. But at the peak of the storm, that number rose to nearly 115,000 particles per square meter per day.
Because of Larry's trajectory and all the precautions the researchers took, “these microplastics could only have come from the garbage patch and not North America,” Professor Walker said.
Considering that the area of Newfoundland and Labrador is approximately 405,000 square kilometers, these approximately 115,000 microplastic particles per square meter per day represent an astronomical amount of pollution.
Health and environmental risks
Microplastic particles are less than five millimeters long. They are usually so small that they cannot be seen with the naked eye. They arise from the breakdown of other, larger plastic products and have been detected in every environment on the planet.
The risk they pose to the health of people, animals and ecosystems remains poorly understood. For example, the researchers point out that these particles are small enough to contaminate groundwater, which is a source of drinking water for thousands of people.
In addition, the study authors write: “Because of their small size and because they are already airborne, microplastics can enter organisms, including humans, through respiration, with health consequences that are still largely unknown.”
“I think it is important for the public to understand that microplastic pollution is everywhere,” Professor Walker said. Then we can put pressure on decision-makers to take the necessary measures to reduce plastic pollution.”
The conclusions of this study were published by the renowned journal Nature.