The Sasanians and chemical warfare

[Imperial Dave]

https://www.thecollector.com/dura-europos-rome-sasanian/

A dirty bomb...

[Duncan Head]

The "chemical warfare" thesis is a rehash of Simon James' 2011 article.

[Ian61]

SO₂ is heavier than air so will longer in the tunnels if it isn't forceably flushed out. It paralyses the diaphragm and intercostal muscles so breathing becomes more and more difficult. Horrible way to go.