Before we get to worrying about property value, it seems like there is no reliable information on safety, especially in the long term. Expert advice isn't reassuring. Take this report from NPR, for example:

https://www.npr.org/2023/02/14/1156567743/health-east-palestine-ohio-train-derailment-chemicals

Quote:
"Now that we are entering into a longer-term phase of this, people are going to be concerned about the long-term chronic exposure that comes at lower levels," said Karen Dannemiller, a professor at Ohio State University who studies indoor air quality.

She added that indoor spaces can be an important point of exposure, which is why she urges East Palestine residents to take part in the EPA's at-home air screening.

Dannemiller recommends that residents wipe down surfaces, especially areas that collect dust, and wash items that absorb smells, such as bedsheets and curtains. She also advises vacuuming carefully in short bursts to try to prevent contaminants from moving into the air.


So your house may be contaminated with a dangerous carcinogenic chemical, and all you have to do is... wipe down surfaces & vacuum carefully?

This sort of situation -- not having enough information -- is common in emergencies. Sometimes your life may be at stake. What's your strategy? Just roll the dice? Follow the plan that you made? Trust your gut?