http://www.bbc.co.uk/news/magazine-19116438
Armies in Scandinavia are so concerned about the pollution caused by
lead bullets they're replacing their entire stock with non-toxic
versions. The manufacturers are encouraging the British armed forces to
do the same.
Then the soldiers kept getting sick.
"Research showed that the combination of new bullets and new weapons
caused increases in emissions of carbon dioxide, ammonia and hydrogen
cyanide." Wait a minute HYDROGEN CYANIDE?