I do my best to minimize micro plastics but also try not to worry about things I can't control. That cat is already out of the bag, micro plastics are inescapable. The silver lining this study show that they aren't that dangerous and its relatively easy for the body to get rid of them over the course of a month. While obviously its hard to say about long term toxicity it seems that life is at least generally resilient to it.

If I may add one personal anecdote. My parents were born in the 60s and 70s. They chain smoked cigarettes for many decades before their health finally caught up with them. Yet somehow they resisted the numerous toxins and carcinogens and tar they exposed themselves too every moment of the day. Maybe they are just really lucky but also maybe living things that got this far in the evolutionary tree already have expetience in biologically adapting to survive. Our cells aren't such easy pushovers to die over any and every little changes in the environment or new chemical players introducing themselves in the game of life.