Any scientific paper that does not document how things were done (methodologies) is basically worthless in the search for truth.

I agree completely. My point is that documenting methodology is standard practice, as is strict quality control, in the microplastics literature. I don’t know what controls are missing according to GP, and we don’t yet have references here to back up that claim. By and large I think researchers are aware of the difficulties measuring this stuff, and doing everything they can to ensure valid science.