$SO_{2}$ pollution is indicated by

Which of the following metals is a water pollutant and causes sterility in human beings?

Lead concentration in blood is considered alarming if it is

Match the columns:

Column-$I$	Column-$II$
$(1)$ Mercury	$(a)$ Low blood pressure,blindness
$(2)$ Lead	$(b)$ Hyperkeratosis,liver cirrhosis
$(3)$ Arsenic	$(c)$ Bone deformation,testicular atrophy
$(4)$ Cadmium	$(d)$ Abdominal pain,haemolysis
	$(e)$ Anaemia,convulsions

Assertion: $A$ suspended particulate matter $(SPM)$ is an important pollutant released by diesel vehicles.
Reason: Catalytic converters greatly reduce pollution caused by automobiles.

$BHC$ and $DDT$ belong to which class of pesticides?