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).
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.
Exposure duration: continuous for 4 hr/day (from 10:00 to 14:00) on 30 days
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 duration||continuous for 4 hr/day (from 10:00 to 14:00) on 30 days|
|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||-||-|
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.