Question: Why can a cockroach survive a bomb blast

Sarah Martin answered on 20 Jun 2012:

Hi aniket!

Cockroaches are really tough animals with a very hard shell. They couldn’t actually survive sitting near a bomb, but the fact is that lots of cockroaches survived the nuclear attacks by the Americans on the Japanese cities Hiroshima and Nagasaki at the end of world war two. To find out how, scientists have done experiments on cockroaches, subjecting them to 1,000 radon units (rads) of cobalt 60, capable of killing a person in 10 minutes, and followed it up with 10,000 and 100,000 rad exposures on separate groups of cockroaches. (As a comparison, the bomb on Hiroshima emitted radioactive gamma rays at a strength of around 10,000 rads.)
A month later, half the roaches exposed to 1,000 rads were still kicking, and a remarkable 10 percent of the 10,000 rad group was alive! The results confirmed that cockroaches can survive a nuclear explosion – but only to a point, as none of the critters in the 100,000 rad group made it through. 🙁

Cockroaches’ ability to withstand extreme radiation exposure may come down to their simple bodies and slower cell cycles. Cells are said to be most sensitive to radiation when they’re dividing. That’s why humans are more vulnerable — they have some cells that are constantly splitting up.
Roaches, on the other hand, only molt about once a week at most, which makes radiation’s window of opportunity to attack cells much narrower.

🙂 Sarah