Sewer Gas Toxicity: A Literature Review

Abstract

Sewer gas toxicity is still a major concern even today, and we still have deaths reported from sewer gas toxicity
especially among the people who work within sewers. These gases are highly toxic when inhaled in large amount
or when inhaled for prolonged period of time. Sewer gas is a combination of Hydrogen Sulphide, Ammonia,
Carbon-dioxide, Sulphur dioxide, Nitrogen dioxide, and carbon monoxide. Hydrogen sulphide, in combination
with CO2 and Methane, formed in sewers, is known as ‘sewer gas.’ Sulphuretted hydrogen is the principal and
dangerous component in sewer gas. It produces multi organ involvement and it is crucial to timely diagnose and
provide high quality resuscitation and care to prevent complications including deaths. Therefore, clinicians must
be aware about this toxicity.Though manual scavenging has been prohibited by Indian law, still a lot number of
lives are lost while cleaning sewage and in manholes. This is due to the toxic gases formed within the sewage
due to decomposition, collectively known as sewer gases. The clinical presentation is wide and varied and has
high mortality rate, if not treated in time. The treatment includes timely identification. decontamination, specific
antidotes including amyl nitrite, sodium nitrite, bronchodilators and even hyperbaric oxygen therapy would be
helpful in severe cases. But as always prevention is better than cure. Hence people involved in manual scavenging
should be given all safety equipments and adequate protective gears because ‘all lives matter’. This is a narrative
literature review on sewer gas toxicity to create awareness among clinicians that this toxicological emergency
exists, though not widely discussed. According to the National Commission for Safai Karamcharis (NCSK), 1298
deaths were reported from 1993 to 28thFebruary 2025.