Microplastics are tiny plastic particles less than 5 millimeters in size. They can originate from larger plastic items that break down over time or from products like cosmetics and synthetic fabrics that release small fibers during washing. These particles are found in various environments, including oceans, rivers, and even in the air. Due to their small size, microplastics can be ingested by marine life, leading to potential harm to ecosystems and food chains. They have also been detected in drinking water and food, raising concerns about their impact on human health and the environment.