Question

What is sewage? In which way can sewage be harmful to us?

Answer 1

Hint:Sewage is the waste water released from homes, industries into the natural water sources. They contain harmful chemicals and also disease causing microbes. It can be in the form of solid or liquid waste.

Complete Answer:
Sewage is the waste water which is discharged to lakes, rivers, ocean and seas. The wastewater can be discharged from the residences and institutions which carry feces and urine, or the commercial waste which is the industrial waste or surface runoff which can contain suspended particles from the soil or particulate matter from the atmosphere. It can also include certain microbes which can cause pathogenic effects.
The sewage can be harmful to us in many ways-
The sewage carries the pathogenic organism which can cause disease in both plants and animals.
The sewage causes foul odour which can attract flies and act as an irritant.
The sewage can cause disease to sea animals. This sea animal which when consumed causes disease in humans. For example minamata disease in Japan due to discharge of mercury in the sea which was eaten by the fishes. This fish when consumed by humans caused fatal effects.

Note:Due to increasing industrialization and population explosion, the sewage is increasing day by day. Nations have adopted ways and measures of treating the sewage before discharging into the water bodies. The treatment includes treating in biofilters. The treated sludge can be used as a bio-fertilizer.