IRMO, South Carolina. Irmo, South Carolina, has a population of 11,223 and is located 10 miles northeast of Columbia, the capital of South Carolina. Chartered in 1890, the town was named for two officers of the local railroad whose names were Irdell and Mosley.
Either way--don't play with plutonium. The most toxic substance I could come up with is botulinum toxin--yes, the same material that is purified and injected (Botox) to remove wrinkles! When injected, the fatal dose is 1.3 to 2.1 nanograms per kilogram. So for an 80 kg adult, 104 to 168 nanograms (0.000168 mg).
The Indo-Pacific or Australian box jellyfish (Chironex Fleckeri) is claimed to be the most venomous marine animal known to mankind and its sting is often fatal. This extremely poisonous marine stinger frequents Australia's northern oceans all year round.