CompuServe Messages

I think it's tough for people to understand even straightforward numbers like relative risk of dying in a car versus an airplane… Can you place those numbers in perspective? For example, what's a common way to produce H2S, and how much of those reactants would produce enough gas in a closed 10 x 10 room in order to reach 0.05 percent? What's a common reaction that produces the whiff of obvious odor?