Medical/biological study (experimental study)

Effects of extremely low frequency electromagnetic fields on distortion product otoacoustic emissions in rabbits med./bio.

By: Budak B, Budak GG, Ozturk GG, Muluk NB, Apan A, Seyhan N

Published in: Auris Nasus Larynx 2009; 36 (3): 255-262

To study the effects of extremely low frequency electromagnetic fields on cochlear function and auditory sensation in rabbits.

20 female rabbits were randomly divided into two groups (each n=10): 1) exposure to 50 Hz electromagnetic fields with 5.068 kV/m; 2) exposure to 50 Hz electromagnetic field with 10.182 kV/m. DPOAE measurements were performed on the day before exposure and on day 6 and 14 after exposure.

Exposure	Parameters
Exposure 1: 50 Hz Exposure duration: continuous for 3 hr/day on 14 days	electric field strength: 5.068 kV/m (at U = 2240 V) electric field strength: 10.182 kV/m (at U = 4500 V) magnetic flux density: 0.00218 nT (at U = 2240 V) magnetic flux density: 0.00445 nT (at U = 4500 V)

Frequency	50 Hz
Type	electric field magnetic field
Waveform	sinusoidal
Exposure duration	continuous for 3 hr/day on 14 days

Exposure source	copper sheets (74 cm x 50 cm x 0.2 mm) on the top and bottom of the cage
Setup	70 cm x 50 cm x 20 xm wooden cage with wooden blocks attached under it for insulation

Measurand	Value	Type	Method	Mass	Remarks
electric field strength	5.068 kV/m	-	calculated	-	at U = 2240 V
electric field strength	10.182 kV/m	-	calculated	-	at U = 4500 V
magnetic flux density	0.00218 nT	-	-	-	at U = 2240 V
magnetic flux density	0.00445 nT	-	-	-	at U = 4500 V

Exposed system:

effects on auditory system: cochlear functions, auditory sensation (distortion product otoacoustic emissions DPOAE; mean stimulus intensity and emission amplitudes for the frequencies 1, 1.5, 2, 3, 4, 6, 8 kHz); ear examination (otoscope)

Investigated system:

Investigated organ system:

Time of investigation:

In rabbits exposed to 5.068 kV/m (group 1), at 2 kHz the DPOAE amplitudes were significantly lower at 6 and 14 days after exposure than the values before exposure. In rabbits exposed to 10.182 kV/m (group 2), the DPOAE amplitudes were significantly increased at 2 and 4 kHz compared to before exposure. Also in group 2, at 6 kHz, amplitudes were significantly lower 14 days after exposure compared to 6 days after exposure.
The results suggest that extremely low frequency electromagnetic fields might affect hearing function. Higher exposure values caused an increase of cochlear activity.

Study character:

Budak GG et al. (2009): Effects of intrauterine and extrauterine exposure to GSM-like radiofrequency on distortion product otoacoustic emissions in infant male rabbits
Budak GG et al. (2009): Effects of extremely low frequency electromagnetic fields on transient evoked otoacoustic emissions in rabbits
Budak GG et al. (2009): Effects of GSM-like radiofrequency on distortion product otoacoustic emissions in pregnant adult rabbits
Budak GG et al. (2009): Effects of GSM-like radiofrequency on distortion product otoacoustic emissions of rabbits: comparison of infants versus adults
Morales J et al. (2009): Low frequency electromagnetic radiation and hearing
Adrian DJ (1977): Auditory and visual sensations stimulated by low-frequency electric currents