Skull and crossbones

[Silcrows]

Hi all, for some reason my city is plagued with Skull and Crossbones icons and buildings are being abandoned. But I cant figure out what could be causing it. I have checked all types of emergency vehicle access, all fine, healthcare fine, clean water, everything from what I can tell. does anyone have any idea what it could be?

Thanks :)

[Apocalypse_Later]

Do you have Cemetary? Corpses, the skull icon, will stick around unless you build one.

[Moxa9]

If it's in an industrail area the pollution can be doing a lot of the work.

[Silcrows]

I have many cemeteries and crematoriums. They are quite far away from Industrial areas, though is there a way to view air pollution?