I have family, including small children, that live in Pittsburgh, ~40 miles from the Ohio train derailment.

Their water supply should not be at risk from the spill itself, being out of the downstream watershed of the spill. But the subsequent burning of the vinyl chloride (and other chemicals) could -- on my understanding -- could have spread dioxins (and other chemicals) over a wide area. Pittsburgh was somewhat downwind of the area, at least during some of the burn.

I've found evaluating claims about risk very hard, am mostly ignorant of chemistry, and don't particularly trust pronouncements from the EPA.

Has anyone found a good resource summarizing the state of knowledge and current risks for those downwind of the crash? Dioxins apparently stay in soil for a while and can accumulate in animals -- should they refrain from eating animals raised in the area? Or even from eating vegetables grown in the area?