Most of the data was collected through the stories that the people told the researchers. This was the best way for them to collect data, since most conditions are best told through stories. They were then able to pull numbers out or ask specific questions catered to the story.
The real threats of air quality were covered up due to politics and other reasons, wanting to get america back to work. Instead, the reports were edited and people were sent back into the dirty air to clean up the scene or back to office jobs in the area, with contaminated air surrounding everything. Decontanimation efforts did not start until very late in the process. Bush did not wear a mask and the workers were told they didn't need to, so they didn't. As a result, there were severe health problems afterwards.
This article is not about a disaster. Just allow more medical stories to circulate.
The authors reference main research articles and books written about the subject from the past.
They also reference epidemiological and sociological studies in supporting their mental health arguements.
Other health references, such as the DSM and Indexes are referenced in the article.
Interviews were conducted with inmates and politicians.