I live in one of the industrial "hot zones" for these chemicals. In the 1960's a local tannery was the main employer in the area, and commanded a great deal of local clout. As a result, they obtained permits to dump industrial waste in various (30+) small dump sites around the area. This waste contained a variety of industrial chemicals, not the least of which was the 3M product Scotchgard, which was used in large quantity to waterproof leather, contains PFAS, and was buried feet from the surface, generally in nondescript forest areas.
A few years ago, when our local water authority began testing for PFAS, they found unusually high numbers specifically around one well-head used to supply municipal water to the area. Instead of disclosing the issue, the authority chose to use that well head only when the demand was high, which excluded times in which the water was tested. If they timed their testing to times of low demand, the numbers were under the EPA recommendation.
With significant grass-roots pressure in the area, many pending lawsuits, and lots of reporting and investigation, the municipality is taking the issue somewhat seriously. GAC filters were installed on the municipal supply, the company considered largely at fault has agreed to pay for the extension of municipal water to some (not all) affected areas that are still served by well water, in which the danger is particularly high. Some cleanups are occurring, while other sites exist under what are now housing developments.
There's story after story here, of people (especially those located in areas served by well water) with a history of cancer after cancer after cancer affecting their entire families. These are folks who after having their water tested, confirmed some of the highest levels ever measured in a water supply.
In all, the whole ordeal has been a wake up call for me, regarding the level of cover-up that happened and in some cases continues to happen surrounding waste disposal, especially for large companies that are considered the "economic life blood" of a given area. Looking over records, people have found strong objections to the practice dating back to the time it happened (some of the warnings eerily prescient) multiple cleanups that were funded but never occurred in the decades that followed, and a continual failure to acknowledge any risk surrounding the practice and dump sites for decades. There was a constant drum beat of "very smart people say that everything is fine."
As for me, my (municipal) water is GAC and RO filtered. I pay close attention to things I would not have considered before, like air quality. It's made me reconsider the source of the foods that I eat. It takes little work to take these precautions, the potential upside is pretty big, and the downside small.
I wonder if in the years to come, we're going to find significant causal links between aspects of our environment and maladies we previously considered a mystery.