Contributions of Electron Microscopy to Environmental Science

Abstract

Heightened concern about the environment, and particularly the increasing rate of dispersion of toxic substances and irritants has placed severe demands on analytical techniques to define the nature and occurrence of potentially hazardous constituents and devise control technologies as well as to determine the risk to human life. In many cases, environmental contamination involves the presence of very fine particulates, which may pose some health risk in their own right or may simply serve as carriers for hazardous chemicals that fall within the respirable range, i.e. 10 microns or less in major dimension. Electron microscopy, widely used to observe and identify fine particulates in the atmosphere, has already contributed significantly to environmental science but advances in instrumentation are needed to overcome technical and economic limitations to its use.Sources of Environmental ParticulatesAtmosphere particulates, popularly considered to originate primarily from heavy industrial operations such as mining, primary metal production or power generation, can also come from natural sources such as volcanoes, forest fires, silt residue from flooding, and botanical emissions (spores, pollen). Paniculate pollutants also derive from smoking, debris from road wear of automobile and truck tires, fragmentation of asbestos-containing insulation and building materials, food processing, earth moving operations, open burning of agricultural residues and waste dumps and unfiltered emissions from incinerators.