Microplastics generally enter the environment through wastewater (like when you are washing a product off your face), and appear to be easily transported from there. Microplastics have now been detected almost everywhere: in the air, our food and drinking water, aquatic and terrestrial ecosystems, and even remote polar regions. 

Once in the environment, plastics and microplastics are extremely slow to decompose, to the point where scientists suggest that all of the plastic that has ever been released still exists today.  These materials, and the negative effects they may cause, are expected to persist for decades and centuries.

Microplastics ecotoxicology is a relatively new field of study, and there are still many gaps in our knowledge. However, a growing body of evidence suggests that microplastics have a negative impact on a range of biological systems, from primary producers (such as algae and plants) to larger organisms (like marine animals, and possibly humans).

While larger plastic components (like packaging) can be managed through effective recycling programs, microplastics are virtually impossible to intercept. Because of their small size, microplastics cannot be captured by standard water treatment facilities, and eventually end up in a range of environments and food chains.

So the only way to protect environmental health from microplastics is to not use them in the first place.