Microplastics: new analysis questions earlier study methods

A recent analysis finds that several peer-reviewed studies reporting micro- and nanoplastics in human tissues face methodological challenges, citing lab contamination, false positives from fatty tissue, and limits in detection technology.

A recent analysis finds that several peer-reviewed studies reporting micro- and nanoplastics in human tissues face methodological challenges. The review reports that lab contamination and false positives, including signals from fatty tissue that can resemble polyethylene, have affected some results. It also notes limits in detection: many microparticles are likely too large to cross into blood, while the smallest nanoparticles can be below available detection thresholds. Some laboratories used workarounds such as vaporizing tissue samples for analysis, but those procedures raise contamination risks when conducted in environments that contain plastic materials. Key findings: - The analysis identifies methodological challenges in multiple published studies reporting micro- and nanoplastics in human tissues. - Lab contamination and cross-contamination are reported as common risks during sample handling and analysis. - Fatty tissues can produce signals that lead to false positives for polyethylene, the analysis reports. - Many microparticles are probably too large to enter the bloodstream, while nanoparticles may be too small for current detection methods. - Some testing approaches, including converting tissues to vapor for analysis, increase contamination risk when performed in plastic-rich lab settings. Summary: The analysis calls into question several reported findings of plastics in human organs by highlighting contamination risks and detection limits. Undetermined at this time.