Sometimes there are little changes to laws that have unknown medical impact. Some of that is related to how it affects the scientific process. Some of that is related to what we do not know scientifically.

For example, on July 1, 2026, the CDC changed its mandatory infection surveillance policy for states. It used to require states to track a number of infectious pathogens. In July, they decreased the number to only two of them. They were Salmonella and E.coli. Other pathogens became optional to track.

One of the optional pathogens was Cyclospora. We then had an epidemic of Cyclospora a few weeks later. It is unlikely that mandatory tracking would have stopped it from beginning in the first place. However, once it began, because there had been less tracking this year, it was more difficult to bring under control.

We will never know for sure about the exact impact of the change in the law on the Cyclospora epidemic. Maybe it made it worse. Maybe it did not. In this case, the scientific process was affected.

Recently, the EPA has been rolling back some of the regulations for air pollutants. There has also been an announcement about cutting back on some of the pollution control requirements for vehicles.

Back in 2021, Harvard did a study that suggested that one of the main reasons for the recent increase in autism was related to air pollution. It appeared to affect developing brains in the third trimester of pregnancy. I wrote an article about that at the time.

We will likely never know for sure if the increased pollutants will cause more cases of autism or not. This is an example of something we do not know for sure scientifically.

PFAS (polyfluoroalkyls) are forever chemicals found in drinking water. They have been linked to a number of diseases. The EPA is currently looking at changing the rules to allow higher levels of these chemicals in water.

PFAS have been linked to a number of medical issues. Those include certain types of cancer. They include high blood pressure. They include pregnancy-induced increases in blood pressure. They include interference with the immune system. They include liver and kidney damage. They include thyroid issues. They include reduced birth weight in infants.

We will likely never know for sure if such a change results in significantly more of the diseases to which they have been linked.

Science cannot conclusively prove everything. It can sometimes do so. However, it is more likely to point people in the right direction. There are a number of times that our laws conflict with scientific evidence. Unfortunately, the exact impact of those laws will never be known.