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Is there is an odor in your home that smells like rotten eggs. Perhaps its coming from your water. Have you smelled it for a long time and were wondering if there were any long term health effects from breathing in low doses of this odor over a long period of time?
First, the rotten egg smell that you are experiencing is most likely hydrogen sulfide (H2S) gas. Hydrogen sulfide gas is a natural product of decay, and in a residential setting, is most commonly a result of decomposition in septic or sewer systems. Some communities that have high concentrations of sulfur in their soil also tend to have detectable hydrogen sulfide in their water.
While extremely high levels of hydrogen sulfide can indeed be harmful, even deadly, H2S is one of those chemicals that can be detected by the nose at an extremely low level. In fact, it can be detected by the human nose at a concentration 1/400 times lower than the threshold for harmful human health effects.
A sudden onset of a strong odor may cause for concern. Hydrogen sulfide rapidly fatigues the sense of smell, so while your nose is a good early detector, it cannot be relied upon over time. If you notice a sudden and a strong onset to the rotten egg odor, move to fresh air, and contact your local health department.
If you detect a faint odor from time to time, it is probably not at a concentration high enough to cause health effects. Hydrogen sulfide does not accumulate in the body; acute health effects don't occur until the exposure to H2S is greater than the body's ability to excrete the excess sulfur. Fortunately, our bodies do possess a natural mechanism to rapidly excrete hydrogen sulfide at concentrations that most people are exposed to under normal everyday circumstances. Most of the injuries related to H2S occur in occupational settings where the potential to be exposed to sudden bursts of H2S are much greater than the residential setting.