All of the following contribute to pollution $EXCEPT$:

The Bhopal gas tragedy is associated with which of the following?

What is the result of the presence of excessive nutrients in water bodies?

Use of lead-free petrol or diesel is recommended to reduce the pollutants emitted by automobiles. What role does lead play?

Delhi is one of the most polluted cities of the world. Which of the following steps were taken by the government to reduce vehicular pollution in Delhi?
$I.$ Phasing out of old vehicles
$II.$ Use of unleaded petrol
$III.$ Use of low sulphur petrol and diesel
$IV.$ Use of catalytic converters in vehicles
$V.$ Applying stringent pollution level norms for vehicles
$VI.$ Switch over of public transport from diesel/petrol to $CNG$
Which of the statements given above are correct?

Eutrophication results in the reduction of