Which is not a water pollutant?

Options

A. Automobile exaust
B. Plant nutrietns
C. Oxygen demanding wastes
D. Disease causing agent.

Answer

To determine which option is not a water pollutant, let's analyze each of the given choices step by step.

### Step 1: Analyze Automobile Exhaust
- **Definition**: Automobile exhaust refers to the gases and particulates emitted from the combustion of fuel in vehicles.
- **Impact on Environment**: Primarily contributes to air pollution rather than water pollution. It does not directly contaminate water bodies.

**Conclusion**: Automobile exhaust is not a water pollutant.

### Step 2: Analyze Plant Nutrients
- **Definition**: Plant nutrients include substances like nitrogen and phosphorus that are essential for plant growth.
- **Impact on Environment**: When these nutrients enter water bodies (e.g., through runoff from agricultural fields), they can lead to eutrophication, which depletes oxygen in water and harms aquatic life.

**Conclusion**: Plant nutrients can be a water pollutant.

### Step 3: Analyze Oxygen Demanding Waste
- **Definition**: This type of waste includes organic matter that requires oxygen for decomposition.
- **Impact on Environment**: When such waste enters water bodies, it is decomposed by bacteria, which consume oxygen. This can lead to a decrease in dissolved oxygen levels, harming aquatic organisms.

**Conclusion**: Oxygen demanding waste is a water pollutant.

### Step 4: Analyze Disease Causing Waste
- **Definition**: Disease-causing waste includes pathogens such as bacteria and viruses that can contaminate water.
- **Impact on Environment**: This type of waste can lead to waterborne diseases and is a significant concern for public health.

**Conclusion**: Disease-causing waste is a water pollutant.

### Final Conclusion
After analyzing all options, the only one that does not contribute to water pollution is **automobile exhaust**.

### Answer: Automobile exhaust is not a water pollutant.

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