Q:

Virulent , Pernicious and Detrimental

I would like to compare the words virulent, pernicious and detrimental in a certain contexts in terms of meaning so order to make sure I use them correctly.
From the definitions on dictionaries I can say that the words detrimental and pernicious overlap more in a sense of something harmful, while virulent has a sense of something poisonous or deadly. It is not hard to see virulent reminds of the noun virus. However,  apparently being used in certain context, virulent still conveys a sense of something harmful because viruses are harmful or detrimental.
I will give some examples and would like to ask if they sound correct.

Being exposed to second-hand smoking in public places is as virulent
  as active smoking.
Being exposed to second-hand smoking in public places is as
  detrimental as active smoking.
Being exposed to second-hand smoking in public places is as
  pernicious as active smoking.

However I am less sure about these following examples:

Being exposed to violence at early ages is likely to has virulent
  effects on children's psychological developments.
Being exposed to violence at early ages is likely to has detrimental
  effects on children's psychological developments.
Being exposed to violence at early ages is likely to has pernicious
  effects on children's psychological developments.

Virulent also has a meaning of stern or harsh as in "virulent/harsh criticism/remarks" or  can be said to imply that you have negative feelings or you are disapproving. Do other words work in the following sentence as well?

Virulent individualism can cause fall apart relationships in a society.
Pernicious individualism can cause fall apart relationships in a society.
Pernicious individualism can cause fall apart relationships in a society.

A:

Detrimental is the most general of these, as it simply means "mildly harmful":

Smoking can be detrimental to one's health.

Virulent means "like a virus":  spreads quickly, hard to get rid of, and usually detrimental:

There has been a virulent sense of disenfranchisement spreading through the Western world.

Pernicious is perhaps the most specific of these, as it means "bad, but often in a way that is subtle, sneaky, and generally difficult to detect."

Both the FBI and the CIA have now claimed that Russian hackers exerted a pernicious influence on the recent US election.

So these three words are distant synonyms at best, and should not be swapped for each other.

