Industries are necesary for the development of a nation by the following ways. 

1. When goods made in factories and exported to other countries, we get revenue. 

2. A few decades before, three-fourths of income from goods exported from manufacturing industries alone. 

3. Even today, nearly two-third of goods exports is contributed by industries and particularly small industries. 

4. Factory goods exported range from gems, jewellery, chemicals, cars, machinery, cashewnuts, etc.

5. The money or foreign exchange earned in this process enable us to import from other countries a large number of goods that we want from other countries. 

At the same time industrial activities are increasing environmental pollution by the following ways. 

1. The production process in industries involves the use of electricity and application of different chemicals. 

2. In the course of production, these industries release a lot of other materials. They are causing pollution in the industrial locations. 

3. The industrialization led to the indiscriminate exploitation of minerals, forests, soils, air, etc.

4. It leads to deforestation and damages the natural habitat of animals. 

5. Underground water is being contaminated due to the release of wastes by the industries. 

6. Some animals are endangered and some creatures have become extinct. 

7. The depletion of ozone layer, pollution of water, air, soil has increased ecological problems.