Primary Disciplines of Technical Expertise

The main environmental application of electron microscopy is in the characterization of particulate materials. The most commonly encountered kinds of particulates are a) asbestos in air, tissue, water, food, and construction materials, and b) fly ash and other fallout particles from combustion processes, but we are experienced in the characterization of almost any type of particle in virtually any matrix.

In the case of asbestos analysis, the appropriate analytical protocols prescribed by various regulatory agencies are followed. Our protocols for asbestos fibers in air filters (AHERA and NIOSH protocols) and water samples (EPA 600 protocols) are based strictly on TEM, the only method sure to resolve respirable fibers unambiguously.

In the case of tissue samples, primarily lung tissue, samples can be prepared and examined both qualitatively and quantitatively for the presence of any asbestos fibers. First, the tissue matrix is removed by oxygen plasma digestion in an SPI Plasma Prep II Plasma Etcher. Fiber structures are examined using selected area electron diffraction with confirmatory EDS data, all being done in the JEOL 100CX TEM to determine the concentration of fibers per unit dry weight of tissue. Structure Probe, Inc. was one of the first laboratories in the world to develop procedures for the quantitative determination of asbestos fibers in lung tissue, and this work since its inception has been done under the direction of Dr. Andrew W. Blackwood.