Microplastics in the body may be less widespread than thought.

Recent reviews and expert critiques have challenged several high-profile studies reporting microplastics in human tissues, leaving the extent of microplastics in people uncertain.

Recent critiques and reviews have questioned a number of studies that reported microplastics in human tissues and organs. Critics told The Guardian that some high-profile findings may reflect methodological errors, including signals from human tissue that can mimic plastic. Several challenged papers and a separate review flagged possible false positives and other gaps in lab procedures. Authors and some experts acknowledge the field is early and say methods need further development. Key points: - The Guardian identified at least seven widely cited studies that were later challenged, and a review flagged 18 more studies for overlooking tissue-produced signals that can mimic plastic. - A headline study claiming detectable microplastics in the brain and other reports were publicly contested by specialists who cited possible false positives from biological material such as fat. - Some authors defended their findings while also noting uncertainties; other researchers have said the reported masses of plastic in organs are not biologically plausible given typical exposure. - Plastic pollution remains widespread, but the presence and amount of intact microplastics in human organs is currently uncertain pending improved methods. Summary: Experts and reviews have raised substantial questions about several studies that reported widespread microplastics in human tissues. The current status is uncertainty because of possible false positives and methodological limitations. The next procedural step described by researchers is further work on methods, replication, and quality controls to clarify what the evidence actually shows.