Hiroshima Study guide chapter 2 help

It was believed that the nausea was directly related to the gas dropped by the Americans.

They all felt terribly thirsty, and they drank from the river. At once they were nauseated and began vomiting, and they retched the whole day. Others were also nauseated; they all thought (probably because of the strong odor of ionization, an “electric smell” given off by the bomb’s fission) that they were sick from a gas the Americans had dropped.