Ferromagnetic contamination in the lungs and other organs of the human body

Our plain-English summary of Ferromagnetic contamination in the lungs and other organs of the human body, by D. Cohen (Science, 1973).

The study

• Author: D. Cohen
• Journal: Science
• Published: 1973;180(4087):745-8
• Cited by: 104 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Contaminating particles which are ferromagnetic have been found in the human body. Their distribution was measured by applying an external magnetic field to the torso for a short time, and then, in a shielded room, mapping the steady magnetic field around the torso due to the magnetized particles. Maps of subjects show various distributions, including particles in the stomach from food cans and in the lungs from are welding. The fields from these two sources are strong enough to be detected with a flux-gate magnetometer, without the need for a shielded room. This simplicity of detection of larger amounts of ferromagnetic contamination suggests that this method may be used in two applications: in detecting the presence of large amounts of asbestos (ferromagnetic and harmful) in the lungs of asbestos workers, and in tests of the condition of the lung where FE(3)O(4) dust (ferromagnetic and harmless) would be used as an inhaled tracer material.

In plain English

This 1973 report described a way to detect ferromagnetic particles, called ferromagnetic contamination, inside the body. The author briefly magnetized each torso, then mapped the particles' steady magnetic field in a shielded room. Some 30 subjects were mapped. Most showed almost no lung contamination but a moderate amount in the abdomen. After one subject ate canned green beans, about 60 micrograms of can particles were estimated in the stomach. An arc welder had lung contamination. Among subjects with lung contamination from their jobs, the one with the most, about five times the welder's, had processed asbestos for many years. The asbestos worker described, who had processed chrysotile at a Quebec mine, had a lung reading of 150 x 10^-7 gauss although his chest x-ray was normal. This lung field was easily seen with a flux-gate magnetometer outside the shielded room. Assuming a magnetite-to-asbestos weight ratio of 0.04, the author estimated 75 micrograms of asbestos per cubic centimeter of lung. The author suggested that, if the magnetite-to-asbestos ratio was known, flux-gate measurements might help monitor asbestos in miners' lungs.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Methods report describing a magnetic measurement technique, with example measurements on human subjects
• Who was studied: Some 30 subjects, chosen both at random and for special contamination. They fell into three groups: a 'normal' group; people who voluntarily ate canned food or inhaled magnetite dust for the study; and people with lung contamination from their occupations, including an arc welder and an asbestos worker. Measurements were made in the M.I.T. shielded room. No dates were given.
• Exposure: Ferromagnetic particles from canned food, arc welding, inhaled magnetite (Fe3O4) dust, and occupational processing of chrysotile asbestos at a Quebec mine. The author attributed asbestos's ferromagnetism to magnetite particles adhering to chrysotile fibers.
• Main results:
  • Most subjects tested, called the normal group, showed almost no contamination in the lungs but a moderate amount in the abdomen.
  • In the subject who ate canned green beans, about 60 micrograms of can particles were estimated in the stomach.
  • In the arc welder, the lung region behind one grid point was estimated to contain 0.6 micrograms of magnetite or maghemite per cubic centimeter of lung. The welder's chest x-ray was normal.
  • Within the group whose lungs had accumulated contamination from their occupations, the subject with the most contamination, about five times as much as the welder, had worked for many years processing asbestos.
  • The asbestos worker who had processed chrysotile showed a lung field of 150 x 10^-7 gauss, but his chest x-ray was normal.
  • Measured outside the shielded room with a flux-gate magnetometer, this asbestos worker's lung field was easily seen above the noise.
  • The asbestos density in this worker's lungs was estimated at 75 micrograms per cubic centimeter of lung.
  • After magnetization, the fields from inhaled magnetite and other lung particles decreased continuously, by as much as a factor of 6 during the first hour.
• The authors' conclusion: The author concluded that a magnetic measurement can be a more sensitive indicator than an x-ray of the particles, including asbestos, actually present in the lungs. The author suggested that, if the ratio of magnetite to asbestos is known, flux-gate measurements may be useful to monitor accumulated asbestos in miners' lungs. The author also suggested inhaled magnetite as a harmless lung tracer.
• Limitations the authors state:
  • The asbestos estimate rests on an assumed magnetite-to-asbestos weight ratio of 0.04. The author noted the ratio is higher before milling and lower after refining.
  • Quantities were estimated by assuming the contamination is pure magnetite.
  • The maps had coarse spatial resolution, partly because of the magnetization method used.

Related studies

• Magnetic lung measurements of relation to occupational exposure in asbestos miners and millers of Quebec — D. Cohen, T.S. Crowther, et al. (1981)
• A procedure for the isolation of asbestos bodies from lung tissue by exploiting their magnetic properties: a new approach to asbestos body study — V. Borelli, C. Brochetta, et al. (2007)
• Magnetometric evaluation for the effect of chrysotile on alveolar macrophages — T. Keira, M. Okada, et al. (1998)
• A comparison of the ferruginous body and uncoated fiber content in the lungs of former asbestos workers — R.F. Dodson, M.G. Williams, et al. (1985)
• Presence of asbestos bodies in organs other than the lung — O. Auerbach, A.S. Conston, et al. (1980)
• Asbestos body concentrations in human lung: predictions from asbestos body counts in tissue sections with a mathematical model — R.T. Vollmer, V.L. Roggli (1985)

Browse more research in Science, or return to medical research.