In message , at 18:51:23 on
Tue, 27 Feb 2007, Mike Ross remarked:
A dirty bomb is a conventional explosive device designed to spread
radioactive 'shrapnel' around, any biological component would be killed by
the radioactivity long before delivery.

Not quite. It's a conventional explosive device designed to spread
*biological* 'shrapnel' around. It doesn't have to be a very big bang,
either. Just enough to do the spreading. And nothing radioactive
involved at all.

I beg to differ; my understanding is that a 'dirty bomb' has always
been thought of as being radiological in nature. A chemical or
biological weapon doesn't *need* explosive - the agent can simply be
released into the environment and allowed to disperse naturally.

Whatever term people are familiar with, that latter weapon was the risk
I was meaning.
--
Roland Perry