@neglesaks Kurzgesagt's latest video has a mention of this as well, saying that living in a 1.6km radius around a coal ash pile increases cancer risk by 2000x above acceptable limits.
See: https://youtu.be/Us2Z-WC9rao?t=486

Also, coal ash dam spills are horrifying events:
https://youtu.be/a91UqFEMs5A

It's so easy to think that concentration is everything, and that high level waste is incredibly dangerous - but the sheer quantity of coal ashes, combined with the hazardous materials contained within it, makes it much harder to manage safely and a greater risk overall.