Sewer gas

[1] Sewer gases may include hydrogen sulfide, ammonia, methane, esters, carbon monoxide, sulfur dioxide and nitrogen oxides.

Sewer gas is typically restricted from entering buildings through plumbing traps that create a water seal at potential points of entry.

The result is the most common means of sewer gas entering buildings and can be solved easily by using the fixtures regularly or adding water to their drains.

In some cases airflow around buildings and wind effects may contribute to sewer gas odor problems even with appropriately separated vents and air intakes.

During the mid-nineteenth century, when indoor plumbing was being developed, it was a common belief that disease was caused largely by miasmas, or literally "polluted air.

"[2] (Malaria, a disease spread by mosquitoes that breed in marshy areas, got its name from the Italian words for "bad air" because people initially blamed it on marsh gas.)

However, during the Broad Street cholera outbreak in London, in the summer of 1854, physician John Snow, among others, worked to prove that polluted water was the culprit, not the foul smells from sewage pipes or other sources.

Exposure to low levels of this chemical can irritate the eyes, cause a cough or sore throat, shortness of breath, and fluid accumulation in the lungs.