Microplastics are everywere: In the oceans, in the soil, in our food. But the most direct way to be exposed to these nasty particles is through infusion during surgery. Scientists found that 1 l of saline solution in a polypropylene bottle contains 7500 microplastic particles on average. With a size distribution of 1 - 62 µm they are big enough to clog the smallest capillaries in the human body with diameters between 5 and 10 µm.