How much should we worry about the health effects of microplastics?

It seems that every few months we discover microplastics in a new part of the body. We have found them in our liver, kidneys, lungs and gut. They have even shown up in human breast milk and blood. Last week, they turned up again in eight people’s olfactory bulb, a brain structure crucial for smell.

These plastic fragments are so small – less than five millimetres in size – that they can make their way into our bodies through food, water and even…