Many studies in recent years have looked at microplastics and nanoplastics, or tiny plastic pieces. A number of them have shown that tiny plastics can be found throughout our bodies. They can even be found in the brain. But after reviewing many of those studies, some scientists are warning that it may be hard to tell just how much microplastic each of us carries in our system. There is little debate that microplastics are everywhere. They’ve been found in human water supplies. They've been found in food. And they've been found in soil. The tiny bits have also been observed in our guts, lungs, bloodstreams, and brains. Yet the methods scientists use to find microplastics in the body are still evolving. That’s why a number of experts have advised caution about the many studies on the subject that have come out over the past two years. Roger Kuhlman is a chemist. He spoke to The Guardian about the studies. We are "re-evaluat(ing) everything we think we know about microplastics in the body. Which, it turns out, is really not very much,” he said. One example: an article published in February 2025 in the journal Nature. Its authors reported finding large amounts of plastic in the brains of dead people. But others pointed out an issue with the tool used to detect the plastic. It often records false positives when it comes across certain types of fats. These include fats that are naturally found in the human brain. Authors of the Nature study and others have pushed back on the critique of their methods. But they also admit that the study of microplastics is still in its infant stages. Reflect: When experts don’t all agree about new information, what steps do you personally take to decide what to trust?
