Michael Gray wrote:

Radiation warning gains skull and crossbones
23 February 2007


"You couldn't call it subtle. The International Atomic Energy Agency
(IAEA) is adding a skull and crossbones and the figure of a person
running away to its warning symbol for dangerous ionising radiation.

"Too many people get injured each year when they find a large source
of radiation, don't understand the symbol and take off the lead
shielding," says Carolyn MacKenzie of the IAEA. In recent incidents,
people have died trying to salvage cobalt sources from dumped medical
equipment.

When the IAEA tested the original radiating "trefoil" symbol at an
international school, it found that many children mistook the trefoil
for a non-threatening propeller. So on 15 February it launched the new
design, adding alarming images to the trefoil.

The IAEA tested it in 11 countries. "It means stop, run away," says
MacKenzie. "Most people got the message."
From issue 2592 of New Scientist magazine, 23 February 2007, page 4

Brilliant. Absolutely brilliant. Kids in Mexico associate a skell and cross
bones with candy.
It's why "Officer Ugg" was developed in California because of the poisoning
associated with the skull symbol.

I wonder how they make it clear that the person is running away rather than
running to share his find.