“Hydrogen sulfide is as lethal, molecule for molecule, as cyanide. This may explain why humans evolved such exquisite sensitivity to its smell.” — Mary Roach Copy Share Image
“Hydrogen sulfide is so swiftly lethal that farm- and workplace-safety organizations urge anyone who enters a manure pit or attempts to clear a blocked sewage pipe to wear a self-contained breathing apparatus.” — Mary Roach Copy Share Image
