Study type: Medical/biological study (experimental study)

Exposure to extremely low frequency electromagnetic fields alters the behaviour, physiology and stress protein levels of desert locusts. med./bio.

Published in: Sci Rep 2016; 6: 36413-

Aim of study (acc. to author)

The effects of exposure to a 50 Hz magnetic field on the neuro-muscular system and motor activity of locusts should be investigated.

Background/further details

A well-studied insect was used to investigate the effects of strong magnetic fields in close proximity to the high voltage power lines on flying insects.
Locusts were divided into the following groups: exposure to a magnetic field with a magnetic flux density of 1) 1 mT, 2) 4 mT or 3) 7 mT. For each exposure group and test, a separate sham exposure group was used. Different groups with different numbers of locusts were used in the individual tests:

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 24 hours
Exposure 2: 50 Hz
Exposure duration: continuous for 24 hours
Exposure 3: 50 Hz
Exposure duration: continuous for 24 hours

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 24 hours
Exposure setup
Exposure source
Chamber circular glass chamber (15 cm diameter x 7.5 cm height)
Setup a coil of 20 cm diameter and composed of 282 turns of insulated copper wire produced a homogeneous, vertical field; glass chamber with 6 locusts was placed inside the coil; temperature during exposure was monitored (at 1 mT, no change was observed (room temperature, 21°C), at 4 mT it was 24.5°C ± 1°C and at 7 mT it was 29.3°C ± 1°C)
Sham exposure A sham exposure was conducted.
Additional info during sham exposure, a hot plate under the coil was used to ensure the same temperature in the glass chamber as during exposure (not necessary for 1 mT)
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 mT - measured - -

Exposure 2

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 24 hours
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 4 mT - measured - -

Exposure 3

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 24 hours
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 7 mT - measured - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Motor activity was significantly reduced in locusts exposed to the 4 mT and 7 mT magnetic fields (groups 2 and 3) compared to the respective sham exposure groups.
The muscle force of the hind leg was significantly decreased in group 3 while the latency and duration of the FETi action potential was significantly increased compared to the sham exposure group.
Protein expression of Hsp70 was significantly increased in metathoracic ganglia of group 3 compared to the sham exposure group.
The authors conclude that exposure to a 50 Hz magnetic field of more than 4 mT might lead to a fatigued neuro-muscular system and reduced motor activity in locusts.

Study character:

Study funded by

Related articles