That advice came in guidelines issued to residents of Guam on how to prepare for a missile threat on the island. The reason is conditioner can trap radioactive particles in strands of hair.

Stardust From Supernova Explosion That Rained Iron Particles Down on Earth Discovered in Antarctic Snow Published Aug 21, 2019 at 11:23 AM EDT Updated Aug 23, 2019 at 4:39 AM EDT By Aristos Georgiou ...