Not sure what you’re trying to say? Asbestos is a natural mineral - not sure where you think that fits into this or how it’s relevant, sorry. We aren’t just listing all things that are naturally occurring!

It was implied in the parent context that the fact coal is "naturally" radioactive somehow matters to the fact that it is.

Asbestos is naturally occurring and incredibly dangerous. "natural" has nothing to do with risk to human life.

> "natural" has nothing to do with risk to human life.

Not sure who you think you're disagreeing with? Nobody said otherwise if you read the thread.

Then I have no idea it was necessary to talk about the "naturalness" of radioactive sources at all given the subject matter.

I usually give the "natural" qualification if it is not immediately obvious there are plenty of naturally occuring sources of radioactivity around us. This has mostly to so with human perception of radioactivity being something unnatural, maybe it was not necessary on HN. It does not matter that much in the end with respect to radioactivity.