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Detecting Lung Overload Magnetometry.

PB97206361

Publication Date	1997
Personal Author	Ferin, J.; Morrow, P. E.; Oberdoerster, G.
Page Count	29
Abstract	A magnetic test aerosol and a magnetomeric 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 pulse was then moved between the arrays. The results indicated that the present goemetric 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.
Keywords	Diagnostic equipment Pulmonary system disorders Lung burden Aerosols Rodents Laboratory animals Dust inhalation Inhalation Magnetometry
Source Agency	National Institute for Occupational Safety and Health
Corporate Authors	Rochester Univ., NY. Dept. of Environmental Medicine.; National Inst. for Occupational Safety and Health, Cincinnati, OH.
Supplemental Notes	Sponsored by National Inst. for Occupational Safety and Health, Cincinnati, OH.
Document Type	Technical Report
Title Note	Final rept.
NTIS Issue Number	199724

Detecting Lung Overload Magnetometry.

Detecting Lung Overload Magnetometry.
PB97206361

Publication Date	1997
Personal Author	Ferin, J.; Morrow, P. E.; Oberdoerster, G.
Page Count	29
Abstract	A magnetic test aerosol and a magnetomeric 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 pulse was then moved between the arrays. The results indicated that the present goemetric 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.
Keywords	Diagnostic equipment Pulmonary system disorders Lung burden Aerosols Rodents Laboratory animals Dust inhalation Inhalation Magnetometry
Source Agency	National Institute for Occupational Safety and Health
Corporate Authors	Rochester Univ., NY. Dept. of Environmental Medicine.; National Inst. for Occupational Safety and Health, Cincinnati, OH.
Supplemental Notes	Sponsored by National Inst. for Occupational Safety and Health, Cincinnati, OH.
Document Type	Technical Report
Title Note	Final rept.
NTIS Issue Number	199724