Study type: Medical/biological study (experimental study)

Rescue of Moribund Chicken Embryos by Extremely Low-Frequency Electric Fields. med./bio.

Published in: Explore (NY) 2016; 12 (6): 451-454

Aim of study (acc. to author)

The effects of exposure of chicken eggs to a 1-50 Hz electric field on embryonal development should be investigated. This pilot study was conducted in view of identifying carcinogenic effects of electric fields.

Background/further details

Fertilized, un-incubated White Leghorn eggs were divided into different groups (10-12 eggs each) within two days after laying. Afterwards, eggs from all groups were first stored at 5°C for 1-36 days before being exposed to a 1-50 Hz electric field with 1-40 V/m at 38°C for 1-7 days. A total of 20 groups was tested with different combinations of storage duration at 5°C, exposure duration as well as field frequency and strength. For each of these groups, a separate control group was used, which was incubated at 38°C without exposure to electric field.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1–50 Hz
Exposure duration: for 1-7 days
groups 1-9
Exposure 2: 4 Hz
Exposure duration: for 3 days
group 10
Exposure 3: 2.5 Hz
Exposure duration: for 5 days
group 11
Exposure 4: 12.5 Hz
Exposure duration: for 4 days
group 12
Exposure 5: 20 Hz
Exposure duration: for 5 days
group 13
Exposure 6: 12.5 Hz
Exposure duration: for 6 days
group 14
Exposure 7: 12.5 Hz
Exposure duration: for 2 days
group 15
Exposure 8: 12.5 Hz
Exposure duration: for 3 days
group 16
Exposure 9: 31.25 Hz
Exposure duration: for 2 days
group 17
Exposure 10: 12.5 Hz
Exposure duration: for 3 days
group 18
Exposure 11: 12.5 Hz
Exposure duration: for 2 days
group 19
Exposure 12: 7.7 Hz
Exposure duration: for 2 days
group 20

Exposure 1

Main characteristics
Frequency 1–50 Hz
Type
Waveform
  • rectangular
Exposure duration for 1-7 days
Additional info groups 1-9
Additional info storage duration at 5°C prior to exposure: 1-18 days
Exposure setup
Exposure source
  • plate capacitor
Chamber styrofoam-insulated stainless steel box (60 x 45 x 25 cm3) kept at 38°C ± 0.2°C
Setup box with pre-warmed eggs (n=10-12) insulated by paper trays was placed between two horizontal aluminum plates (25 cm x 30 cm x 1.5 mm) held 10 cm apart by styrofoam spacers; the lower plate was grounded and the upper plate received an oscillating positive charge
Additional info eggs from control groups were incubated at 38°C in a similar box 20 cm away from the exposure system
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 1 V/cm minimum - - -
electric field strength 40 V/cm maximum - - -

Exposure 2

Main characteristics
Frequency 4 Hz
Type
Waveform
  • rectangular
Exposure duration for 3 days
Additional info group 10
Additional info storage duration at 5°C prior to exposure: 15 days
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 4 V/cm - - - -

Exposure 3

Main characteristics
Frequency 2.5 Hz
Type
Waveform
  • rectangular
Exposure duration for 5 days
Additional info group 11
Additional info storage duration at 5°C prior to exposure: 11 days
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 1 V/cm - - - -

Exposure 4

Main characteristics
Frequency 12.5 Hz
Type
Waveform
  • rectangular
Exposure duration for 4 days
Additional info group 12
Additional info storage duration at 5°C prior to exposure: 14 days
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 4 V/cm - - - -

Exposure 5

Main characteristics
Frequency 20 Hz
Type
Waveform
  • rectangular
Exposure duration for 5 days
Additional info group 13
Additional info storage duration at 5°C prior to exposure: 20 days
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 4 V/cm - - - -

Exposure 6

Main characteristics
Frequency 12.5 Hz
Type
Waveform
  • rectangular
Exposure duration for 6 days
Additional info group 14
Additional info storage duration at 5°C prior to exposure: 18 days
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 4 V/cm - - - -

Exposure 7

Main characteristics
Frequency 12.5 Hz
Type
Waveform
  • rectangular
Exposure duration for 2 days
Additional info group 15
Additional info storage duration at 5°C prior to exposure: 10 days
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 4 V/cm - - - -

Exposure 8

Main characteristics
Frequency 12.5 Hz
Type
Waveform
  • rectangular
Exposure duration for 3 days
Additional info group 16
Additional info storage duration at 5°C prior to exposure: 12 days
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 2 V/cm - - - -

Exposure 9

Main characteristics
Frequency 31.25 Hz
Type
Waveform
  • rectangular
Exposure duration for 2 days
Additional info group 17
Additional info storage duration at 5°C prior to exposure: 20 days
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 4 V/cm - - - -

Exposure 10

Main characteristics
Frequency 12.5 Hz
Type
Waveform
  • rectangular
Exposure duration for 3 days
Additional info group 18
Additional info storage duration at 5°C prior to exposure: 22 days
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 4 V/cm - - - -

Exposure 11

Main characteristics
Frequency 12.5 Hz
Type
Waveform
  • rectangular
Exposure duration for 2 days
Additional info group 19
Additional info storage duration at 5°C prior to exposure: 25 days
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 4 V/cm - - - -

Exposure 12

Main characteristics
Frequency 7.7 Hz
Type
Waveform
  • rectangular
Exposure duration for 2 days
Additional info group 20
Additional info storage duration at 5°C prior to exposure: 36 days
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 4 V/cm - - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Increasing storage durations at 5°C without subsequent electric field exposure (control groups) caused a steady loss of embryo viability with a half-life of about 18 days after more than 12 days of storage. Surprisingly, exposure to an electric field after storage increased the embryo viability significantly, resulting in a new half-life of about 21 days after more than 12 days of storage.
However, some of these rescued embryos showed malformations (e.g. two heads) which have not been reported in eggs from this supplier over many years.
The authors conclude that exposure of chicken eggs to a 1-50 Hz electric field might keep embryos alive which would otherwise not have survived. Carcinogenic effects of electric field exposure should be searched in these rescued embryos.

Study character:

Study funded by

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