Researchers find microplastics even in our guts

Microplastics have been found just about everywhere on earth, from the sea salt shaker on your table to the Arctic Circle. They’re in pharmaceuticals, detergents and consumer products like toothpaste, and now those microplastic pieces have been found – perhaps not surprisingly – in human poop.

Researchers from the Medical University of Vienna and the Environment Agency Austria say they monitored a group of eight participants from around the world, including Finland, Italy, Japan and the Netherlands, Poland, Russia, the United Kingdom and Austria.

The study group members were asked to keep a food diary for the week ahead of their stool sampling, and write down everything they ate. None of them were vegetarians, six of them ate sea fish, and all of them recorded foods or drinks that confirmed they were exposed to plastic food containers and wraps, or plastic bottles.

Despite their geographic diversity, every single one tested positive for the plastics in their excretions. On average, the researchers found 20 microplastic particles per 10 grams of stool, all ranging in size from 50 to 500 micrometers. The latter is about the size of a mechanical pencil or ballpoint pen tip.

Plastic particles found most often in the stool samples were polypropylene (PP) and polyethylene-terephthalate (PET) with seven other types present; the research team tested for 10 different kinds.

“This is the first study of its kind and confirms what we have long suspected, that plastics ultimately reach the human gut,” said lead researcher Dr. Philipp Schwabl of the Vienna team. He presented his findings to a United European Gastroenterology conference, running from October 20 to 24.

“Of particular concern is what this means to us, and especially patients with gastrointestinal diseases,” Schwabl said. “While the highest plastic concentrations in animal studies have been found in the gut, the smallest microplastic particles are capable of entering the blood stream, lymphatic system and may even reach the liver. Now that we have first evidence for microplastics inside humans, we need further research to understand what this means for human health.”

Microplastics may affect the tolerance and immune response of the gut, either by building up over longer exposures (bioaccumulation) or because they facilitate the work of toxic chemicals and pathogens, the scientists said.

The tiny pieces of plastic are less than five millimeters in size, often beginning that small but sometimes the result of larger plastic products degrading over time. Human exposure to plastics has taken off over the decades, with some 311 million metric tons of plastic produced in 2014 – about 20 times more plastic than was produced in 1964. Those numbers are expected to rise, and plastic has its purposes, but the global community has become more responsive to the waste problem.

Plastic that ends up in the ocean often is consumed by sea animals. Microplastics have been found in tuna, lobster and shrimp consumed by humans, representing one pathway for how it’s getting into people’s diets and therefore, their stools. Beyond that, the researchers say, it is highly likely that food is being contaminated with plastics during processing or as a result of packaging materials.