In the metropolitan cities of India , many children are suffering from allergy/asthma. What are the main causes to this problem. Give some symptoms of allergic reactions.

Explanation

### Step-by-Step Solution:

1. **Identify the Problem**: In metropolitan cities of India, many children are suffering from allergies and asthma.

2. **Determine the Causes**:
- **Pollution**: The primary cause of allergies and asthma in metropolitan areas is high levels of pollution. This includes:
- **Air Pollution**: Emissions from a large number of vehicles contribute to poor air quality.
- **Industrial Emissions**: Factories in and around metropolitan areas release pollutants into the air.
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