The Little-Known Unintended Consequence of Recycling Plastics
Allyson Chiu | May 22, 2023 | The Washington Post
Instead of helping to tackle the world’s staggering plastic waste problem, recycling may be exacerbating a concerning environmental problem: microplastic pollution.
A recent peer-reviewed study that focused on a recycling facility in the United Kingdom suggests that anywhere between 6 to 13 percent of the plastic processed could end up being released into water or the air as microplastics — ubiquitous tiny particles smaller than five millimeters that have been found everywhere from Antarctic snow to inside human bodies.
“This is such a big gap that nobody’s even considered, let alone actually really researched,” said Erina Brown, a plastics scientist who led the research while at the University of Strathclyde in Glasgow, Scotland.
The research adds to growing concerns that recycling isn’t as effective of a solution for the plastic pollution problem as many might think. Only a fraction of the plastic produced gets recycled: About 9 percent worldwide and about 5 to 6 percent in the United States, according to some recent estimates.
The study was conducted at a single plastic recycling facility, but experts say its findings shouldn’t be taken lightly.
“It’s a very credible study,” said Judith Enck, a former senior Environmental Protection Agency official under President Barack Obama who now heads the Beyond Plastics advocacy organization. She was not involved in the research. “It’s only one facility, but it raises troubling issues, and it should inspire environmental regulatory agencies to replicate the study at other plastic recycling facilities.”
How does plastic recycling work?
While there are many different types of plastic, many experts say only things made out of No. 1 and 2 are really recycled effectively in the United States. At recycling facilities, plastic waste is generally sorted, cleaned, chopped up or shredded into bits, melted down and remolded.
It’s unsurprising that this process could produce microplastics, Enck said. “The way plastic recycling facilities operate, there’s a lot of mechanical friction and abrasion,” she said.
Brown and other researchers analyzed the bits of plastic found in the wastewater generated by the unnamed facility. They estimated it could produce up to 6.5 million pounds of microplastic per year, or about 13 percent of the mass of the total amount of plastic the facility receives annually.
The researchers also found high amounts of microplastic when they tested the air at the facility, Brown said.
Will filters help?
The study also looked at the facility’s wastewater after filters were installed. With filtration, the estimate of microplastics produced dropped to about 3 million pounds a year.
Even with the use of filters at the plant, the researchers estimated that there were up to 75 billion plastic particles per meter cubed in the facility’s wastewater. A majority of the microscopic pieces were smaller than 10 micrometers, about the diameter of a human red blood cell, with more than 80 percent below five micrometers, Brown said.
She noted that the recycling facility studied was “relatively state-of-the-art” and had elected to install filtration. “It’s really important to consider that so many facilities worldwide might not have any filtration,” she said. “They might have some, but it’s not regulated at all.”
While effective filters could help, Brown and other experts said they aren’t the solution.
“I don’t think we can filter our way out of this problem,” Enck said.
