Study type: Medical/biological study (experimental study)

Studies on the synergistic effects of extremely low-frequency magnetic fields and the endocrine-disrupting compound atrazine on the thyroid gland. med./bio.

Published in: Int J Radiat Biol 2010; 86 (12): 1050-1060

Aim of study (acc. to author)

To study the effect of extremely low frequency magnetic fields and the endocrine-disrupting compound atrazine (each separately) on the thyroid gland of juvenile-peripubertal rats (postnatal days 23-53), and to investigate the possible synergistic effect of these two factors combined (co-exposure).

Background/further details

Animals were divided into six groups (each group n=12): 1) magnetic field exposure group, 2) atrazine treatment group (daily 20 mg/kg of body weight), 3) atrazine treatment group (daily 200 mg/kg), 4) magnetic field exposure with atrazine treatment (20 mg/kg), 5) magnetic field exposure with atrazine treatment (200 mg/kg), and 6) control group.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 4 hr/day (from 10:00 to 14:00) on 30 days

General information

Animals were divided into six groups: i) exposure to EMF ii) 20 mg/kg body weight of atrazine iii) 200 mg/kg body weight of atrazine iv) 20 mg/kg body weight of atrazine + exposure to EMF v) 200 mg/kg body weight of atrazine + exposure to EMF vi) control group

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous for 4 hr/day (from 10:00 to 14:00) on 30 days
Exposure setup
Exposure source
Distance between exposed object and exposure source 12 cm
Setup solenoid equipped with a cooling system; cages with animals placed on both sides of the solenoid; inhomogeneous field with the maximum field on the side of the cage near the coil
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 100 µT minimum measured - ICNIRP limit for public exposure
magnetic flux density 300 µT maximum measured - ICNIRP limit for working environment
electric field strength 54 V/m minimum measured - -
electric field strength 160 V/m maximum 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)

The data demonstrated no significant alterations in the thyroid structure between the treated groups and the control group. Significant results were found regarding the volume density of thyroid follicles and the connective tissue between the magnetic field exposed group and both atrazine treatments as well as between the magnetic field exposed group and the combined treatments (co-exposures).
Only the high dose of atrazine alone significantly affected the number of mast cells compared with the control group.
In conclusion, no synergistic effect of the magnetic field and the endocrine-disrupting compound atrazine on the thyroid gland was found. The specific histological alterations of the thyroid parenchyma observed in some treated groups require further investigation.

Study character:

Study funded by

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