Microplastic pollution knows no boundaries. The contaminants have been found in the U.K.’s lake and rivers, in U.S. groundwater, along the Yangtze river in China and on the coast of Spain, according to new studies.
Less than 5 millimeters in size, the minuscule pieces of plastic often shed from larger, disintegrating pieces of pollution and are blamed for the spread of plastic waste into the food chain. In 2018, microplastics were found in human stool for the first time, with researchers estimating that half of the world’s population could have microplastic in their systems.
Despite this, the research on the abundance and effects of microplastics is just beginning. Researchers in Wales recently tested 10 iconic U.K. lakes and rivers, finding microplastics in every one of them. In the River Thames in London, tests revealed 80 microplastic particles per liter; in the River Tame in Manchester, it was more than 1,000.
“It was startling. I wasn’t expecting to find as much as we did,” Christian Dunn at Bangor University, Wales, told The Guardian. “It is quite depressing they were there in some of our country’s most iconic locations.”
In China, microplastics were found all along the middle and lower Yangtze River, especially near megacities, with an average of 500,000 items of plastic per square kilometer. In coastal Spain, researchers analyzing microplastics found an average of 100,000 items per square kilometer, primarily polyethylene, polypropylene and polyester.
In the U.S., researchers who tested groundwater in the St. Louis area and northwestern Illinois found microplastics in all but one sample, with a maximum of 15.2 particles per liter. “The research on this topic is at a very early stage, so I am not convinced we have a frame of reference to state expectations or bounds on what is considered low or high levels,” study co-author Tim Hoellein, a biology professor at Loyola University Chicago, told Phys.org. “Our questions are still basic—how much is there and where is it coming from?”
Study co-author John Scott, a researcher at the Illinois Sustainable Technology Center, says 6.3 billion metric tons of plastic have been produced since the 1940s, with 79% of that now in landfills or discarded. “Even if we quit plastics cold turkey today, we will still deal with this issue for years because plastic never really goes away,” Scott said. “To me, it is such a weird concept that these materials are intended for single use, yet they are designed to last forever.”