Question

The presence of Escherichia coli in water in high amount is a strong indication of

• A. Industrial pollution
• B. Sewage or animal waste contamination
• C. Hardness of water
• D. Presence of chlorine in water

Hint:

E. coli is the "Universal Indicator" for fecal pollution. If you see it in a pond, it means there is a leak from a septic tank or livestock waste is washing into the water.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks for the interpretation of finding high concentrations of the bacterium Escherichia coli (E. coli) in a water source.

Step 2: Detailed Explanation:

• E. coli as an Indicator Organism: E. coli is a bacterium that lives naturally in the intestines of warm-blooded animals and humans. It is generally not found naturally in the environment (water/soil) in high numbers unless introduced recently.

• Fecal Contamination: Because E. coli is excreted in feces, its presence in water is a specific "indicator" of fecal contamination from sewage or animal waste runoff. While most strains of E. coli themselves are not harmful, their presence suggests that other dangerous waterborne pathogens (like Salmonella, Vibrio cholerae, or viruses) that live in feces may also be present.

• Public Health Significance: High E. coli counts in aquaculture ponds can lead to the contamination of fish/prawn products, making them unsafe for human consumption and leading to the rejection of export consignments.

• Other Options: Industrial pollution (A) is usually indicated by chemical markers or heavy metals. Hardness (C) is a mineral property. Chlorine (D) actually kills E. coli.

Step 3: Final Answer:
High E. coli indicates sewage or animal waste contamination.