Study type: Medical/biological study (experimental study)

Extremely low frequency magnetic fields affect transposition activity in Escherichia coli. med./bio.

Published in: Radiat Environ Biophys 2003; 42 (2): 113-118

Aim of study (acc. to author)

To verify whether extremely low frequency magnetic fields could affect transposition activity like some environmental stress factors such as heat shock or UV irradiation.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: experiment 1: continuous for 34 h; experiment 2: continuous for 58 h

General information

The magnetic fields and the frequency used in the study were selected for the exposure as they are a common exposure in urban environments and in domestic appliances.

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration experiment 1: continuous for 34 h; experiment 2: continuous for 58 h
Exposure setup
Exposure source
Chamber incubator at 37°C
Setup five Petri dishes (9 cm in diameter) were placed in the center of the coil system
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 100 µT effective value measured - -
magnetic flux density 0.2 mT - - - -
magnetic flux density 0.5 mT - - - -
magnetic flux density 1 mT - - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Bacteria that had been exposed for a long time (58 h) to a 50 Hz low intensity magnetic field (0.1-1 mT) gave colonies with significantly lower transposition activity compared to sham-exposed bacteria. Such reduction in transposition activity was positively correlated to the intensity of the magnetic field, in a dose-effect manner. This phenomenon was not affected by bacterial cell proliferation, since no significant differences were found in number, diameter and perimeter between exposed and sham-exposed colonies.

Study character:

Study funded by

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