- Microplastics are found in oceans, soils, air, drinking water, food, and the human body, but accurate measurement is challenging due to contamination risks in labs and false positives from lipids in blood mimicking polyethylene.
- Lab contamination is a major issue because plastics are ubiquitous in lab equipment and air; researchers rebuilt a lab with stainless steel and glass to reduce contamination, lowering plastic levels by a hundredfold.
- Common sources of microplastic exposure in homes include synthetic fibers from dryers, tire particles on balconies, plastic chopping boards, utensils, and food containers, with recommendations to switch to metal, wood, or bamboo alternatives.
- The claim that humans ingest a credit card's worth of plastic weekly has been debunked; actual shedding from plastic containers is measurable but much lower, and many plastic particles are too large to enter the bloodstream and are excreted.
- Key unanswered questions include the size and type of plastics that can enter the bloodstream, the effects of inhaling synthetic fibers, and the health impacts of microplastic particles themselves, beyond known risks from additives like phthalates and bisphenols.