Detecting lung overload by magnetometry.
Ferin-J; Morrow-PE; Oberdorster-G
Department of Environmental Medicine, University of Rochester, Rochester, New York 1996 Jul; :1-27
A magnetic test aerosol and a magnetometric system were developed for the measurement of dust clearance rates in rodents. Fischer-344 rats were exposed to micronized 1 to 5 micrometer diameter magnetite and micronized 250 micrometer diameter titanium-dioxide aerosols, alone or as a mixture. Magnetometry was performed using eight flux gate magnetometers in two arrays. A rat was placed in a restraint tube and exposed to a brief magnetization pulse; the tube was then moved between the arrays. The results indicated that the present geometric design gave reproducible measures of magnetite dust in the lungs of rats. At low lung burdens of magnetite the in-vivo method of magnetometry reflected the retention behavior of these particles reasonably well. At high lung burdens, the measured retention of magnetite may not accurately reflect the actual behavior of these particles. The relaxation rate of the magnetic signal of the retained particles may be useful as an indicator of the localization of the particles. The authors suggest that further development of the magnetometric method for noninvasive measurement of the pulmonary particle clearance function in humans should be based on a thorough analysis of the observed discrepancy in measured retention half times between low and high magnetite lung burdens.
NIOSH-Grant; Pulmonary-system-disorders; Dust-inhalation; Laboratory-animals; Lung-burden; Inhalation-studies
Environmental Health Scis Ctr University of Rochester 601 Elmwood Ave, Box Ehsc Rochester, NY 14642
Final Grant Report
NTIS Accession No.
Department of Environmental Medicine, University of Rochester, Rochester, New York
University of Rochester, Rochester, New York