The following water samples are given with their $BOD$ values. Which sample has the lowest level of pollution?
Sample $w - 6 \ mg/L$,Sample $x - 6.5 \ mg/L$
Sample $y - 7 \ mg/L$,Sample $z - 10.3 \ mg/L$

Name the states involved in the Ganga Action Plan.

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?

Particulate matter with a diameter of $2.5$ micrometres or less and a sound level of $150$ $dB$ or more causes the greatest harm to human health.

The 'Itai-itai' disease is caused by the poisoning of which of the following?

In Minamata Bay,Japan,which of the following animals remained free from Minamata disease?