Asbestos analysis

DNLM 1. Asbestos—adverse effects. 2. Asbestos—analysis. 

A list of 221 laboratories receiving initial accreditation to perform bulk asbestos analysis during the second quarter of 1989 has been released by the National Institute of Standards and... 

Given the need and financial incentives for improved, faster asbestos analysis, studies are ongoing to improve these areas. Intense activity is underway in the areas of automation and computerization, especially with TEM and analytical electron microscopy. Another area of investigation is to identify the fiber types and sizes most closely identified with risk of lung cancer and mesothelioma and develop methodology that will give results that are most closely correlated with risk (Berman et al. 1995). 

Reliability of asbestos analysis should be improved by new regulations requiring accreditation of asbestostesting laboratories. The National Institute of Science and Technology (formerly the National Bureau of Standards) is conducting programs for accreditation of polarized light microscopy and TEM laboratories. 

Sheehan MJ, Reynolds JW. 1992. Airborne asbestos analysis of low fiber density samples A comparison of the A and B counting rules of the NIOSH method 7400. Applied Occupational Environmental Hygiene 7(1) 38-41. 

X-ray diffraction, light scattering, light mod-nlation, IR spectroscopy, and j6-ray absorption are some of the techniques for asbestos analysis. Indnstrially processed asbestos fibers may be characterized by laser microprobe mass analysis (LAMMA). Organic components adsorbed on the asbestos snrface at... 

The EDX system will normally be similar to that described for SEM for energy range and resolution. Additional specifications are required for asbestos analysis in that a backgroimd-subtracted sodium Ka peak from a SOnm-diameter crocidolite fiber should have an integrated count rate of at least one count per second when irradiated by a probe of dimension 250 nm or smaller at an acceleration potential of 80 kV. The peak-to-ground ratio in this analysis should also be at least 1.0. 

All individuals performing asbestos analysis must have taken the NIOSH course for sampling and evaluating airborne asbestos dust or an equivalent course. 

At this time, there is no known method to determine the absolute accuracy of the asbestos analysis. Results of samples prepared through the Proficiency Analytical Testing (PAT) Program and analyzed by the OSHA-SLTC showed no significant bias when compared to PAT reference values. The PAT samples were analyzed from 1987 to 1989 (N=36) and the concentration range was from 120 to 1,300 fibers/mm. ... 

Send the samples to the laboratory with paperwork requesting asbestos analysis. List any known fibrous interferences present during sampling on the paperwork. Also, note the workplace operation (s) sampled. 

Serpentine A mineral family consisting of minerals with the general composition Mg3(Si205(OH)4 having the magnesium in brucite layer over a silicate layer. Minerals important in asbestos analysis included in this family are chrysotile, lizardite, antigorite. 

Because of the subjeotive nature of asbestos analysis, oertain concepts and procedures need to be discussed in more depth. This information will help the analyst understand why some of the procedures are carried out the way they are. 

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. 

Microscopists in every technical field use the microscope to characterize, compare, and identify a wide variety of substances, eg, protozoa, bacteria, vimses, and plant and animal tissue, as well as minerals, building materials, ceramics, metals, abrasives, pigments, foods, dmgs, explosives, fibers, hairs, and even single atoms. In addition, microscopists help to solve production and process problems, control quaUty, and handle trouble-shooting problems and customer complaints. Microscopists also do basic research in instmmentation, new techniques, specimen preparation, and appHcations of microscopy. The areas of appHcation include forensic trace evidence, contamination analysis, art conservation and authentication, and asbestos control, among others. 

Fig. 7. Thermal analysis curves for asbestos (a) chrysotile (b) crocidoHte (in inert atmosphere) (10). Reprinted with permission.

Roh-alkohol, m. crude (or raw) alcohoL -analyse, /. rough or approximate analysis, -antimon, n. crude antimony, -arbeit, /, (Metal.) ore smelting, -asbest, m. crude asbestos. -aufbereitung, /. preliminary preparation, -benzol, n. crude benzene, benzol (or benzole), -blei, n. crude lead, -blende, /. (Mining) crude blende, -block,... 

The standard unit normally used for measuring dust particles is the micron (pm one-thousandth of a millimeter). The smallest particle visible to the unaided eye is between 50 and 100 pm and the most dangerous sizes are between 0.2 and 5 pm. Particles larger than this are usually unable to penetrate the lung defenses and smaller ones settle out too slowly. Some dusts can be both toxic and fibrous (e.g. asbestos) and are therefore harmful even outside these parameters. It may therefore be assumed that dusts which are visible (i.e. between 50 and 100 pm), are quite safe. However, this is not the case, as dust clouds never consist solely of particles of one size. Analysis would show percentages of all sizes, and it is for this reason that special care is needed in measuring dust clouds and concentrations. 

As a consequence of the inhalation of mineral dusts, infiltration into the lung of inflammatory phagocytic cells, namely PMN and macrophages, occurs (Rola-Pleszczynski et al., 1984). Analysis of the cell populations of the rat pleural cavities after injection with asbestos and silica dust also showed both degranulation and reduction of the mast cell population (Edwards etal., 1984), and it is of interest to note that histamine augments the particle-stimulated generation of macrophage superoxide production (Diaz et al., 1979). 

There are two main types of proficiency testing scheme. First, there are those set up to assess the competence of a group of laboratories to undertake a very specific analysis, e.g. lead in blood or the number of asbestos fibres in air collected on membrane filters. Secondly, there are those schemes used to evaluate the performance of laboratories across a certain sector for a particular type of analysis. Because of the wide range of possible analyte/matrix combinations it is not practicable to assess the performance of laboratories when analysing all the possible sample types. Instead, a representative cross-section of analyses is chosen (e.g. determination of different pesticide residues in a range of foodstuffs or the determination of trace levels of metals in water samples). 

Purified asbestos wool ( Gooch crucible asbestos for analysis ). Coarse and fine copper oxide. 

During the analysis the calcium chloride tube is attached directly to the sodium hydroxide-asbestos tube. When the apparatus is not in use this calcium chloride tube is closed with a rubber cap.-... 

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. 

In the early stages of the disease, fibrotic lesions can be found in the bronchioles and alveolar ducts of the pulmonary tree. If exposure to asbestos is not documented in the patient s life history, laboratory examination (tissue analysis), to demonstrate of the presence of asbestos fibers and ferruginous bodies is necessary. However, the demonstration of these bodies in the ab-... 

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