Escherichia coil is used as an indicator organism to determine pollution of water in :

Options

A. Industrial effluents
B. Heavy metals
C. Pollen of aquatic plants
D. Faecal matter

Answer

To solve the question regarding Escherichia coli (E. coli) as an indicator organism for water pollution, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding E. coli**:
- E. coli is a type of bacteria that is commonly found in the intestines of humans and animals. It is part of the coliform group of bacteria.

2. **Role of E. coli in Water Testing**:
- E. coli is used as an indicator organism in water quality testing because its presence suggests that the water may be contaminated with fecal matter. This is important for assessing the safety of drinking water.

3. **Identifying the Source of Pollution**:
- The question presents several options: industrial influence, heavy metals, pollen of aquatic plants, and fecal matter.
- Among these, fecal matter is the most relevant source of contamination that E. coli indicates.

4. **Conclusion**:
- Since E. coli is specifically associated with fecal contamination, the correct answer to the question is that E. coli is used as an indicator organism to determine pollution of water in relation to **fecal matter**.

### Final Answer:
E. coli is used as an indicator organism to determine pollution of water in **fecal matter**.

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