Which of the following is a pollution-related disorder?

Define/Explain the following terms:
$(i)$ Eutrophication
$(ii)$ Jhum cultivation

Foul smell in the water bodies of tanks,ponds,etc.,is due to:

What is the effect of $DDT$ in birds?

What is Agent Orange?

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?