I had a miscarriage once due to carbon monoxide poisoning from a furnace that was later condemned.

There are long term effects to carbon monoxide poisoning...and it doesn't take much.

The fact that there was sufficient CO OUTSIDE to set the detectors off INSIDE is pretty freaking scary. Those people are going to suffer the health effects of breathing this in for a long time to come....and they won't even know it.

Seriously though, if this is an atmospheric thing, we're in huge trouble.