Plastic pollution is usually pictured as something outside the body: bottles on beaches, fragments floating in oceans or waste accumulating in landfill. Increasingly, however, scientists are finding evidence of plastic somewhere much closer to home - inside us.As plastic breaks down, it forms microscopic particles known as microplastics and even smaller nanoplastics. Humans can encounter these particles through food, drinking water and the air we breathe. Researchers have now reported microplast