Alarm bells went off among environmental scientists in February, as COVID-19 spread across Europe and inched toward North America.

Professor Tony Walker was still teaching in full lecture halls at Dalhousie University when he connected with a team of Portuguese researchers to investigate a parallel crisis about to unfold.

We saw the writing on the wall, Walker told HuffPost Canada.

A global pandemic, 7.7 billion people. Therell be a lot of masks.

Based on early data from Italy, the researchers estimated the world would use 129 billion masks each month of the pandemic, according to their article published in June. However, like plastic bags and packaging, single-use masks would be almost impossible to recycle the vast majority destined for landfills or littered.

And if only one per cent of the worlds masks are disposed of incorrectly, 10 million masks per month weighing close to 90,000 pounds will end up in nature, according to the World Wildlife Fund . Thats on top of the 52 billion pounds of plastic carried by rivers into oceans each year, washing up on shorelines, entangling wildlife and contaminating drinking water with microplastics .