Chap. 13. Terrorism, Toxicity, and Vulnerability 333
10 -^510 -^410 -^310 -^210 -^1110102103104105
Parathion
Tetrodotoxin
Botulinus toxin
Nicotine
10 -^6
Sarin
Lethal dose, milligrams/kilogram body mass
If this area represents a
fatal dose of parathion,
the area of the circle below
represents a fatal dose of Sarin
Malathion
Ethanol
Figure 13.2. Relative toxicities of various substances in units of milligrams dose per kilogram of body
mass required to kill 50% of test subjects (LD 50 ). Also shown are the relative toxicities of parathion, a
once commonly used insecticide that has been discontinued because of its toxicity to humans, and Sarin,
an extremely toxic military poison.