Which can be used as industrial pollution indicators ?

Answer

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks for indicators of industrial pollution.

2. **Understand the Concept of Bioindicators**: Bioindicators are organisms or biological responses that can provide information about the health of an environment or the presence of pollutants.

3. **Research Lichens**: Lichens are a symbiotic association between algae and fungi. They are sensitive to environmental changes, particularly air quality.

4. **Lichens and Air Quality**: Lichens absorb their nutrients from the air rather than the soil. This makes them particularly vulnerable to air pollution.

5. **Sensitivity to Pollutants**: Lichens are sensitive to sulfur pollutants and other contaminants. In areas with high levels of air pollution, especially sulfur dioxide, lichens tend to disappear.

6. **Conclusion**: Due to their sensitivity to air pollution, lichens can be used as indicators of industrial pollution.

**Final Answer**: Lichens can be used as industrial pollution indicators.

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