electromagnetic field(redirected from Electromagnetic fields)
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electromagnetic fieldPublic health
An invisible field of electromagnetic radiation on the spectrum of energetic particles that move as quanta (radiowaves, infrared, visible light, UV light and gamma radiation). EMFs are generated by moving electric charges that propagate outward from any object carrying an electric current, and result from:
(1) The electric field that pushes or pulls ions toward or away from the field; the electrical component of an EMF is blocked by most objects, from skin to concrete, and has a strength of 1 mV/m2, which is similar to the strength of the cells’ intrinsic electrical activity;
(2) The magnetic field that acts on moving particles, pushing them perpendicularly to their direction of motion, which passes through most matter without losing strength; the actual power generated by a magnetic field is a few milligauss (1% of the strength of the earth’s magnetic field).
Tumour cells exposed in vitro to extremely low electromagnetic fields (ELF) of 60-Hz electromagnetic radiation from electrical distribution systems (power lines, video display terminals, household appliances) have increased mitotic activity; some reports have suggested that ELF radiation is associated with a 1.5–2.5-fold increase in leukaemia, lymphomas and intracranial malignancy, especially in children living near either 765-kV power lines or 15-kV distribution lines. Although ELF increases ornithine decarboxylase activity or cell membrane resistance to spontaneous lysis, the relationship of ELF to malignancy is controversial and inconclusive.
electromagnetic fieldAbbreviation: EMF
The region in space in which the photons produced by moving electric charges have an effect. EMFs can be produced by power lines, radio waves, and microwaves. The energy produced in an EMF increases as the frequency of the photons increases, and EMFs produced by very high frequency photons (e.g., xrays and gamma rays) are sufficiently energetic to induce cancer.
See also: field