Researchers don’t yet know how dangerous tiny plastics are for human health. In a large review published in 2019, the World Health Organization said there wasn’t enough firm evidence linking microplastics in water to human health, but described an urgent need for further research
Finding a connection between microplastics and health problems in humans is complicated — there are thousands of types of plastics, and over 10,000 chemicals used to manufacture them. But at a certain point, Mason said, policymakers and the public need to prepare for the possibility that the tiny plastics in the air we breathe, the water we drink and the clothes we wear have serious and dangerous effects.
If the negative effects were very strong they would probably have found evidence in previous studies. There may be something here, but it isn't something worth worrying about much.