Doctors at a hospital in Aleppo, Syria, treat a boy injured in what the government said was a chemical weapons attack on March 19. Syria's government and rebels accused each other of firing a rocket loaded with chemical agents outside of Aleppo.
President Obama affirmed Tuesday that there's evidence Syrians have been attacked with chemical weapons — in particular, nerve gas.
But that's not the same as proof positive.
"We don't know how they were used, when they were used, who used them," Obama . "We don't have a chain of custody that establishes what exactly happened."
Proving that someone has violated the on chemical weapons can be very hard. While governments seek more evidence, Syrians may be in danger.
That's why a physicians' organization is trying to help medical workers in Syria recognize the signs of a chemical attack. The effort is meant to save lives, but it could also generate evidence that governments are seeking.
Physicians for Human Rights is a network to get fact sheets about chemical weapons into the hands of Syrian physicians. This group has a long record of working with medical professionals in trouble spots to protect civilians and reveal war crimes.
For the rest of the story: http://www.npr.org/blogs/health/2013/04/30/180074012/how-doctors-would-know-if-syrians-were-hit-with-nerve-gas