Do electromagnetic fields significantly affect thyroid cells and their functions? – A systematic review

Abstract

Background: This review aimed to emphasize the effects, mechanisms involved, conditions required to trigger impacts, and the adapted responses of EMF on thyroid gland. Methods: The included literatures were collected from the Oceania Radiofrequency Scientific Advisory Association (ORSAA) database which were published before April 2021. The searched was then refined with keyword ‘thyroid’. Results: A total of 15 experimental studies, 10 observational studies, 4 review articles, and 1 medical hypothesis were included. Hypothyroidism is the most reported functional abnormality. The identified morphological abnormalities of the thyroid gland include increased follicular epithelial and interfollicular tissue, decreased colloid volume of cubic cells, follicular fluid, interfollicular space, changes in lysosomes, granular endoplasmic reticulum, cell nuclei, changes in glandular structures including cell hypotrophy, glandular hypertrophy, and increased apoptosis via caspase-dependent pathways. The observational studies reported an increase in thyroid cancer incidence and the diameter of the left anteroposterior of the thyroid gland. Postulation that thyroid cancer is associated with thyroid cancer EMF exposure, is suggested by a medical hypothesis paper. The possibilities of hypothyroidism, thyroid cancer, and cell apoptosis due to EMF exposure have been highlighted in the review articles. Conclusion: Despite these findings, critical elements, such as the effects and mechanisms of EMF exposure on thyroid hormone transporters, genomic and non-genomic actions, conditions required for the effect to occur, and the resultant adapted responses, have not been explored suggesting the need of further research.