articles about cyanide gas and comets:

[link to news.nationalgeographic.com]


[link to coupmedia.org]

According to wiki exposure of Cyanide causes the following symptoms:
"
Cyanide poisoning is a form of histotoxic hypoxia because the cells of an organism are unable to use oxygen, primarily through the inhibition of cytochrome c oxidase. If cyanide is inhaled it causes a coma with seizures, apnea, and cardiac arrest, with death following in a matter of minutes. At lower doses, loss of consciousness may be preceded by general weakness, giddiness, headaches, vertigo, confusion, and perceived difficulty in breathing. At the first stages of unconsciousness, breathing is often sufficient or even rapid, although the state of the victim progresses towards a deep coma, sometimes accompanied by pulmonary edema, and finally cardiac arrest. Skin color goes blue from cyanide-hemoglobin complexes. A fatal dose for humans can be as low as 1.5 mg/kg body weight"