Human brain samples contain an entire spoon’s worth of microplastics, study says And researchers say that amount has grown by 50% in just 8 years. Even more alarming? Microplastics aren’t just in the brain - they’ve been found in the lungs, liver, heart, and even the placenta. One source you probably haven’t thought about? Your plastic toothbrush. A recent PubMed study (PMID: 38092338) found that every time you brush, your toothbrush releases about 120 microplastic particles — over 88,000 partic