[kaybe]

You don't need to worry about unknown radioactive exposure. We have a very good monitoring system that will detect even very minor releases once they become distributed. The reporting channels in the west are trustworthy too.

In addition we have widespread atmospheric monitoring as well. You can circumvent that by releasing only substances that are not watched, but I don't think that's that easy, and you'd have to do it intentionally. Eg anything connected with fire will show up.