Caution aside, speculatively this could mean that the serious issue of PFAS contamination in American water supplies made the pandemic worse than it would have been otherwise. Obviously, even if the effect size is relatively large, this would be smaller than more obvious and direct contributors, but it's not nothing at population scale. It's really disconcerting to me that we spent decades using chemicals in everyday household products that are extremely unsafe in a myriad of ways, without even a warning, and we've effectively semi-permanently poisoned all of the major city water supplies in the US.