Question

what problem did manual scavenger face?

Answer 1

Low concentrations of the gas irritate the eyes, nose, and throat, causing respiratory distresses. Headaches, dizziness, and nausea increase with increased exposure. H2S results in ‘olfactory fatigue’, where the brain loses its ability to distinguish the smell, and over time, the entire stimulus gets de-sensitised. This fatigue is one of the main reasons behind men losing consciousness in septic tanks. The presence of the gas goes unnoticed by the olfactory sensors, and when the H2S accumulation in septic tanks or sewers exceeds 300 parts per million (ppm), the gas gets absorbed by the lungs rapidly, causing unconsciousness and increased risk of death.