Or I'm a young person with lots of cancer cases "near me" and I'm worried that we're moving in very undesirable directions and everyone clapping their hands
In my experience, many claims of cancer clusters aren't actually caused by the things people say they're caused by. For example, for a long time people thought living near power lines caused cancer, but careful work suggests that instead, it works through an intermediate variable (people living near power lines often have lower socioeconomic status, which is closely coupled to worse health outcomes).
AI datacenters (or datacenters) are really not the most likely cause- their emissions and impact are far smaller than living near a highway or a coal fired power plant.