That's been getting a lot of play this week, it seems.
http://www.stripes.com/news/exercise-focuses-on-potential-n-korea-biological-chemical-attack-1.160403November 10, 2011
U.S. and South Korean military officials huddled in operations centers over the past two weeks going over, in great detail, how they would respond to a chemical or biological attack from North Korea. . . .
A 2007 Popular Mechanics investigative report stated that, according to defectors, South Korean intelligence agencies and other sources, North Korea has built “one of the world’s most extensive biochemical warfare programs.”
“The weaponry is thought to have the potential to decimate <South Korea> and the 28,000 U.S. troops stationed there,” the story said. . . .
In September, the Yonhap News Agency reported that South Korean lawmaker Shin Hak-yong called for greater efforts to expand the South’s defense against potential biological warfare, saying that North Korea is prepared to spread 13 kinds of biological agents, including anthrax bacterium, the smallpox virus and cholera.