nowadays with verb or verb+ing form

Does anyone know why B is better than A ?

A. Nowadays, public health is a topic that starts to get growing attentions.

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B. Nowadays, public health is a topic that is starting to get growing attention.

Answer

Nowadays is a complex temporal adverb that means much the same thing as Positive anymore.
That is, Nowadays, S asserts that S is true at the present time,
and also presupposes that there was a time in the past when S was false.

• Nowadays, everybody carries a phone.


• Everybody carries a phone nowadays.


• *%Any more, everybody carries a phone. *


• *%Everybody carries a phone any more. *
  (The '%' in front of the sentence means it's dialectal -- see the link for details)

This is the opposite of normal any more -- which is a Negative Polarity Item
and therefore can appear only in a negative clause.
Normally, Not S any more asserts that S is false in the present,
and presupposes that S was true in the past.

• Nobody wears a fedora any more.


• Nobody wears a fedora nowadays.

But the reason why the second sentence is preferable to the first has nothing to do with nowadays.
Start is an active inchoative predicate, and therefore its use in the present tense
is interpreted in a Generic sense. With a punctual predicate like start,
that would mean a repetitive sense, as in

• The motor starts to sputter every time I press the accelerator.

That is, the "present tense" starts to get is not used to refer to the present time;
the progressive is starting to is used instead.