NO! Definitely not! Why would you think that?

But...

There is nothing in this world that is unnatural. By definition, all things that exist in nature are natural. That goes for essential oils, uranium 235, saffron, that weird fluid inside pimples, and asbestos.

All these things are natural, but you wouldn't consume them just based on that fact alone, would you?

Plastics are different in the way that they would not exist if it wasn't for human industry. We as a species are directly responsible for plastics coming into being.

Jeff Goldblum once said "life finds a way". We are already seeing plastics being reabsorbed into the environment and repurposed into new things. We have found concretions and composite rocks that have plastics as a binding agent. It is already a part of the natural world.

While microplastics might be bad for health and potentially even deadly in some cases. Future life will have to adapt to an environment full of microplastics. It wouldn't be illogical to assume that future life might even encorporate plastic as a part of itself.

It wouldn't be hard to imagine some intelligent species living on Earth in the far of future. A father sitting his son down at the dinner table. "Son, have you taken your microplastics today? You gotta take your microplastics if you want to grow big and strong. Your carapace is 97 percent plastic, you know. Kids today have it easy. Our ancestors had to make their own chitin."