Your statement is based on rather short-term tests, I think. I suspect that lower levels of exposure could dull the sense of smell over time. People can lose perception of all kinds of low-level sensory inputs (e.g. their own body odor) with chronic exposure. Incidentally, really high levels of hydrogen sulfide apparently kill the olfactory sense for H2S permanently.
My response was based on the assumption that you were saying H2S has a specific effect at low levels of dulling the sense of smell. This is inaccurate. It has such an effect, one that occurs quite rapidly, but it is at relatively high levels not far below those immediately dangerous to life and health.
The issue you describe is called olfactory fatigue and is common to all odors, not specific to H2S. Anyone around a given odor for long periods of time will eventually decrease in his ability to detect it.
I’ve worked with clients who were positive their 14 cats didn’t create an odor problem in the home. Meanwhile I’m standing there with tears running down my cheeks from the ammonia levels.
No, The body loosing tolerance to low levels, then becoming able to experience the symptoms of higher level exposure at low levels, is based on OSHA/NIOSH longer term tests. Granted, all OSHA/NIOSH tests are generally done on healthy adult men, in the work place. OSHA/NIOSH has no research for CHRONIC (24/7 year after year) exposure to hydrogen sulfide, for infants, children, the elderly, sensitives and pets. In short, these families are the lab rats for such research. This chemical cocktail of sulfur compound gases has no business being found in peoples homes, which is why there have been no case specific studies to reference.