Is Houston really carcinogenic as they say?

Currently living in North Texas suburb of Dallas, possibly planning to move to one of the Houston suburbs since I'm working from home anyways. One thing that bothers me is many are saying Houston is part of the cancer belt and that the air/possibly water are polluted. Is this true for the suburbs as well?

What's your experience as a Houstonian for the quality of life (air & water quality, temperature, overall level of comfort) over there? Is Houston good for health? Also I see quite a lot of rivalry between Houston and Dallas so guess I'm asking the obvious here in this subreddit: which one would you prefer?

FYI I have been to Houston a few times and don't quite recall having any issues then (maybe because they were short stays back then). Thanks