Asbestos chemical analysis

Asbestos can be determined by several analytical techniques, including optical microscopy, electron microscopy, X-ray diffraction (XRD), light scattering, laser microprobe mass analysis, and thermal analysis. It can also be characterized by chemical analysis of metals by atomic absorption, X-ray fluorescence, or neutron activation techniques. Electron microscopy methods are, however, commonly applied for the analysis of asbestos in environmental matrices. 

Detailed treatments of chemical analysis by x-ray diffraction are given by Klug and Alexander [G.39] and Zwell and Danko [14.1]. Nenadic and Grable [14.24] have reviewed diffraction methods of determining quartz, asbestos, and talc in industrial dusts all of these minerals can cause lung disease. 

Optical microscopy (OM), polarized light microscopy (PLM), phase contrast microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and scanning transmission electron microscopy (STEM) are the methods normally used for identification and quantification of the trace amounts of asbestos fibers that are encountered in the environment and lung tissue. Energy-dispersive X-ray spectrometry (EDXS) is used in both SEM and TEM for chemical analysis of individual particles, while selected-area electron diffraction (SAED) pattern analysis in TEM can provide details of the cell unit of individual particles of mass down to 10 g. It helps to differentiate between antigorite and chrysotile. Secondary ion mass spectrometry, laser microprobe mass spectrometry (EMMS), electron probe X-ray microanalysis (EPXMA), and X-ray photoelectron spectroscopy (XPS) are also analytical techniques used for asbestos chemical characterization. 

How do the general framework conditions for the substitution of hazardous chemicals differ from the conditions under which the case of asbestos was dealt with This analysis was so important for the SubChem project because the relevance of the historic case analyses for future substitution processes (cf Chapter 3) had to be assessed. 

XZ/N VI RON MENTAL APPLICATIONS OF CHEMOMETRics are of interest because of the concern about the effects of chemicals on humans. The symposium upon which this book is based served as an important milestone in a process we, the editors, initiated in 1982. As members of the Environmental Protection Agency s Office of Toxic Substances (OTS), we have responsibilities for the acquisition and analysis of human and environmental exposure data in support of the Toxic Substances Control Act. OTS exposure studies invariably are complex and range from evaluating human body burden data (polychlorinated biphenyls in adipose tissue, for example) to documenting airborne asbestos levels in schools. 

Recognizing the applicability of XRD to occupational health chemistry, Lennox and Leroux (1) suggested a number of chemical species which would be suitable for XRD analysis arsenic trioxide, beryllium oxide, mica, vanadium oxides, calcium fluoride in ceramic materials, as well as a number of organics such as DDT, lindane and chlordane. Unfortunately, the general application of XRD to the quantitation of industrial hygiene samples has not been realized and the majority of these analyses are restricted to free silica and to a lesser extent asbestos and talc. 

A major area of concern is the possibility that asbestos fibers adsorb carcinogens in smoke, such as benzidine, N,N-dimethylanaline, and benzo(a)pyrene, and carry them to cells. Investigations are being carried out to detect such chemical impurities on asbestos fiber surfaces by a technique known as laser microprobe mass analysis (Warner 1988). 

From an analysis of the published financial research on the chemical industry, the sustainability issues of concern in the mainstream investment world revolve first around exposure to hot-button issues such as asbestos and genetic modification. There are some indications that this concern may extend to issues that have not yet fully blossomed, such as endocrine disruptors. There is also lingering concern about the potential for European Union rules that, if adopted, would essentially shift the burden of proof from showing that a chemical caused harm to having to demonstrate the safety of a number of chemicals in current use. Among those analyzing the sustainability of the chemical industry, the primary task appears to be to evaluate the companies ability to deal with complex issues of safety, emission reductions, community relations, and so on. 

Prior to the processing of any lithium battery for recycling, the battery s material safety data sheet should be reviewed, and, if necessary, a complete analysis should be performed to determine the waste products. Components and chemicals are unique to each manufacturer and not each type of lithium battery. Many are similar but none are identical. Compoimds that can cause serious concern if overlooked include chrome, arsenic, fluorine, mercury, organic solvents, asbestos, lithium, and others. At the end of this chapter are two typical battery analyses performed by Toxco Inc., exemplifying the... 

Dixon, W.C., Applications of Optical Microscopy in Analysis of Asbestos and Quartz, Analytical Techniques in Occupational Health Chemistry, edited by D.D. Dollberg and A.W. Verstuyft. Wash. D.C. American Chemical Society, (ACS Symposium Series 120) 1980. pp. 13-41. 

The dose of a chemical causing cancer in human or animal studies is then used to set a standard PEL below which only a certain number of people will develop illness or cancer. This standard is not an absolute safe level of exposure to cancer-causing agents, so exposure should always be minimized even when levels of exposure are below the standard. Just as the asbestos standard has been lowered in the past from 5 fibers/cm to 0.2 fibers/cm, and now to 0.1 fibers/cm (50 times lower), it is possible that other standards will be lowered in the future as new technology for analysis is discovered and public... 

The effectiveness of this method was tested using the nuclear reaction C( He,a) C (Q > 0). The zirconium, irradiated by 7 MeV He particles, is practically not activated due to the coulomb barrier. On the other hand, the carbon that it contains is considerably activated via the above nuclear reaction. The thus formed is hence detectable non-destructi-vely, so that it is possible to undertake the chemical separation after this instrumental analysis. The quantity of extracted and trapped on the soda asbestos can consequently be compared to the value determined above, giving the true yield of the process. 

Similarly, the metallurgist must often analyze small areas or inclusions in an alloy or determine the nature of a fractured siuface. These problems can be solved ordy with microanalytical techniques. In the fields of environmental science and contamination corrtrol, the chemist most often analyzes single particles of material a few microns or less in size. Asbestos analysis, for example, as specified by the U.S. Environmental Protection Agency, is to be performed using a polarized hght microscope (PLM), which is the principal tool of the chemical microscopist. 

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