• Measuring device and non-invasive magnetometric method for determination of the long-term contamination level of the human lungs with ferromagnetic dust

Measuring device and non-invasive magnetometric method for determination of the long-term contamination level of the human lungs with ferromagnetic dust

Project: APVT No. 51-017802

Investigators: A. Cigáň, K. Jurča, P. Jurdák, A. Koňakovský, J. Maňka, F. Martinická, I. Šimáček, V. Zrubec

Applicators: St. Cyril and Metod Hospital, Bratislava and Institute of Occupational Medicine and Toxicology, Faculty Hospital, Bratislava

The measuring apparatus and the method for the measurement of the contamination level of the human lungs of people working long-term in the environment, where they are exposed to ferromagnetic dust particles (with possible harmful influence), were developed. The measuring device utilizes the magnetometers with unique SQUID sensors, superconducting gradiometers of own design and other tools for reducing the disturbing signals of the ambient. The measuring method is based on the strengthening of the magnetic properties of particles in the lungs by magnetizing them by external field and after switching off this field, measuring the magnetic field originating from these particles. The measured signal of remanent magnetic induction upon the tested human chest is proportional to the amount of contaminating ferromagnetic particles, their physical properties, it depends on their distribution in the human organs, on their physical, physiological and anatomical properties. Other factors influencing this dependence are the intensity and duration of the applied field. The crucial role in the quantification of the ferromagnetic contaminants play the shape and the volume of human lungs and the volume of the contaminated space. The correction factors corresponding to the anatomy of tested lungs were estimated by theoretical analysis and used in the quantification. They have been tested by measurement on models and people too. We also concentrated on the evaluation of the relaxation characteristics of the industrial ferromagnetic particles (FMP) in solid and liquid environment with different viscosities with the aim to estimate the rate of the decrease of the remanent magnetic induction of tested powders in the measurement time window. The results have been verified by measurements on selected retired welders from the Slovak Shipyard in Komárno and on groups of controls.

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