The catalyst for Return of the Living Dead is when James Karen's character slaps the side of a drum releasing some gas into the atmosphere. The result of this is that every dead organism in the building is brought to life, including a cadaver which is eventually cremated. This in turn revives everything in the nearby cemetery. It's implied that the gas within the cadaver was released by the cremation and deposited into the soil by rain. My question is, how did the amount of gas released cause all of that? Did I miss a line about Trioxin spreading or am I reading too much into this?