Microplastics have been found in people's shit: what does this mean?

Humans are suspected of consuming tiny particles of plastic thus confirming future work on possible health effects

Scientists found them everywhere they were found tiny pieces of degraded plastic – including, now, in the human poop. New research shows what scientists have suspected since microplastics were detected in seafood, salt and bottled water: people eat plastic particles and excrete at least some of them.

Although the study is small, its purpose is to show that microplastics can be detected in excrements and are actually present in them. It is therefore essential to look in the future for broader patterns of human microplastic exposure and potential health impacts.

Microplastics include fragments of less than five millimeters (the diameter of a grain of rice) resulting from the decomposition of large debris, such as bottles, in the environment. They are also made of synthetic fibers and plastic beads added to some cosmetics. They found themselves everywhere, from the bottom of the sea to the land, around the farmland – as well as in the early scientists and food and beverage experts examined – so that almost some people ingest them. But until now, there were no direct samples of humans showing that this was happening.

Stools seemed to be "the most promising place to observe humans for the first time," says co-author of the study, Bettina Liebmann, of the Environment Agency Austria. The detection of microplastics in the poo is delicate, however. She and Philipp Schwabl of the Vienna Medical University spent several weeks developing a method to break down the organic matter present in the feces without affecting the microplastics likely to be present, so that the plastic can be isolated from the samples.

The team collected samples from eight European and Asian participants, who learned how to minimize contamination, for example, fibers floating continuously in the air, the plague of many researchers in microplastics. . Scientists badyzed the stool for microplastics ranging from 50 micrometers (almost twice the diameter of a human skin cell) to five millimeters. "We were quite surprised to find microplastics in each sample," says Liebmann. They also detected nine of the 10 types of plastic polymers they sought most often, including polypropylene (used, for example, in capsules), polyethylene terephthalate (used in beverage bottles) and polystyrene (used in food containers). Although they were unable to identify the exact source of each particle, the results "confirm that we are surrounded by plastic in our daily lives," she says.

The book, presented on October 23 in Vienna during the European Week of Gastroenterology, United European meeting of specialists in digestive health, serves as a starting point for further research. Liebmann and Schwabl hope to launch a larger study with more participants to look for any link between the amount, type and size of plastic particles, people's place of residence, their eating habits and other factors related to fashion. of life. They also hope to find smaller plastics, which are most likely to enter the intestinal wall and enter the circulatory system and other organs, as seen with other reduced size, made by man. 19659004] New research suggests at least some microplastics (at the upper limit of the waist range) are excreted by the body, which Liebmann calls "a good sign". We still do not know how what will come out will compare to what could still be left in the body. "We simply lack the frame of reference," says Martin Wagner, an ecotoxicologist at the Norwegian University of Science and Technology, who did not take part in the new study.

Future work will also need to explore what might possibly exist. Negative health impacts that microplastics could have on the body due to physical injury to the intestines or other organs, or because of the introduction of chemical additives for plastics. Scientists still do not know how microplastics might differ in this respect from other non-digestible particles to which humans are exposed. "We need to know if it's really toxic?" Said Wagner. "We are blind about it."

But with the new work, "we now know how to solve the problem, and we have the tools in hand" to start looking at microplastics in humans beyond the badumptions made. before, says Liebmann. "We now have proof that there is something that deserves to be watched."