Thomas L. Friedman
Discovery-NY Times Channel
documentary Thomas L. Friedman Reporting: Searching for the Roots of 9/11

or

click here

Discovery Channel and the New York Times are trustworthy sources of information, both on the Internet and in writing.

This documentary is excellent.

see also:

Canadian documentary 9/11 Toxic Legacy (Canadian Broadcasting) (Thanks Canada!)

at Wikipedia

or at Discovery Times Channel

Officials slow to hear claims of 9/11 illnesses