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Determination of ferromagnetic dust levels in the lungs by magnetic measurements using a SQUID system

This thesis is an account of research carried out in the Department of Physics, University College of Swansea, on the development of a magnetopneumography system and the assessment of its performance. Magnetopneumography (MPG) is one area within the rapidly growing field of biomagnetism and the development of this field, with detailed references to MPG, is presented in Chapter 1. Physical, chemical and biological aspects of the major iron and nickel-bearing dusts (detection of which is the main aim of MPG) are discussed in Chapter 2. Exposure, toxicity and other biological effects (e.g. carcinogenecity) of these dusts are also reviewed in an industrial context. Details of construction and principles of operation of a SQUID magnetometer are considered in Chapter 3, with particular reference to the Swansea biomagnetometry system. The performance of this system is then investigated by means of remanent magnetisation studies on small polyurethane samples containing known quantities of magnetite and nickel powders. These measurements are presented and discussed in Chapter 4 where the detection limits of the SQUID system are established for this type of study. These results are also used in a study of <i>post mortem</i> lung samples from asbestos miners which forms the subject of Chapter 5. The relevance and benefits of the magnetic technique to occupational health and industrial hygiene are also discussed. In Chapter 6, as a logical continuation of the <i>in vitro</i> work, remanent magnetisation studies (similar to those of Chapter 4) are reported for anatomically accurate whole-lung phantoms. These measurements are compared with a simplified lung model for which an analytical solution is derived. Finally, to demonstrate the suitability of both the technique and the apparatus, <i>in vivo</i> studies on a random selection of healthy volunteers were conducted, the results and implications of which are examined in Chapter 7.

Identiferoai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:635723
Date January 1991
CreatorsAl-Sewaidan, H. A. I.
PublisherSwansea University
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation

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