"Survivors reported a distinct smell of onion and body odour coming from the tunnels shortly before the explosion"
(
Barry Chuckle III - the troll with a soul., Thu 7 Jul 2005, 11:04,
archived)
Erm...
that's how bombs work.
If you mean dirty bombs and that - don't worry. The risk is low except to those close to the bomb, who'll be in a bad way anyway.
(
Rev. A-MOL is lurking around these parts again, Thu 7 Jul 2005, 11:09,
archived)