A scientist with the Environmental Protection Agency (EPA) claimed in a letter to members of the New York Congressional Delegation that test reports in 2002 and 2003 distorted the alkalinity, or pH level, of the dust released when the twin towers collapsed. The EPA scientist is challenging the test results which indicated that larger particles of dust were highly alkaline, but found smaller dust particles (those most likely to reach into the lower airways of the lungs) were not alkaline and caustic.

These smaller dust particles present a greater risk, and residents of Lower Manhattan have sued the EPA and New York University as the parties responsible for the tests, claiming they bungled the cleanup.

During the cleanup, all workers and residents should have been advised to take precautions, such as wearing HEPA masks, which are necessary in any environment with potentially toxic dust or chemicals. Now, as reported by