The information in this report describes the results of an interdisciplinary environmental characterization of the World Trade Center (WTC) area following requests from other Federal agencies after the attack on September 11, 2001. The scientific investigation included two main aspects: 1) imaging spectroscopy mapping of materials to cover a large area around the WTC and 2) laboratory analysis of samples collected in the WTC area.

Spectroscopy is a tool that detects chemical bonds in molecules (solid, liquid or gas) through absorption (or emission) features in the spectrum of the material. Imaging spectroscopy obtains a spectrum for every spatial pixel in an image format. Data from the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) were collected over the WTC area by NASA/JPL for this study. The results of the imaging spectroscopy mapping are shown below.

The analytical techniques applied to this study include X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) with elemental analysis by Energy Dispersive Spectroscopy (EDS), laboratory Reflectance Spectroscopy (RS), leachable metals, and X-Ray Fluorescence Spectroscopy (XRF).

Reprinted with Permission from www.usgs.gov