Which of the following cannot be adulterated in petrol or diesel?

$A$: High concentration of atmospheric $SO_2$ reduces primary productivity.
$R$: $SO_2$ converts the chlorophyll $a$ into phaeophytin.

$A$ location with luxuriant growth of lichens on the trees indicates that the

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

Identify the year of establishment for the Central Pollution Control Board $(CPCB)$ based on the following context:
$(i)$ Environment (Protection) Act: $1986$
(ii) Central Pollution Control Board $(CPCB)$: ?

Exposure to a noise level of $............$ or more for a short period can damage the eardrums,leading to permanent hearing impairment. (in $,dB$)