O.K. I had it bit wrong. Check out this:https://en.m.wikipedia.org/wiki/Larry_SilversteinAnd again, neither the new owners, nor the old owners, were the US government or the CIA.....so what reason would the US government or the CIA become involved in conspiring to destroy the WTC in order to cover up an health/environmental issue there?
Also, for what it is worth, contrary to what you said, the WTC did not change owners shortly before the attacks.
The World Trade Center has been owned by the Port Authority of New York and New Jersey since the day they first began construction on it in August 1968. It is to this day still owned by the Port Authority of New York and New Jersey. It has always been owned by the Port Authority of New York and New Jersey.
Anyway you seem to (perhaps unintetionaly) be twisting what I was saying. I never said there was any need for any health issue cover up. It was an open information.