Some evidence for pollution as major cause of cancer variation by state:
The maps leans toward the east being worse but California has some bad parts.
Air pollution (including indoor pollution) looks to be a significant driver of cancer.
There are a lot of cancer causing substances and it’s probably hard to account for their combined impact. That could make it easier to miss how big of an impact they combine to cause.
Some evidence against pollution as a major cause of cancer variation by state:
Variations in Populations and Health Behaviors
Some differences in cancer rates among states may be explained by differences in known risk factors among the populations of those states. For example, one finds higher rates of lung cancer and other tobacco-associated cancers in states with higher prevalence of smoking. Although environmental carcinogens are responsible for some cancer cases, a majority of cases appear to be related to lifestyle factors such as smoking, and geographic variations in cancer rates are thought largely to reflect variations in these lifestyle factors.
Ambiguous evidence:
https://www.thebody.com/article/hiv-and-aids-in-the-united-states-by-geographic-di