Medical/biological study (observational study)

Effects of electromagnetic radiation exposure on bone mineral density, thyroid, and oxidative stress index in electrical workers med./bio.

By: Kunt H, Senturk I, Gonul Y, Korkmaz M, Ahsen A, Hazman O, Bal A, Genc A, Songur A

Published in: Onco Targets Ther 2016; 9: 745-754

Aim of study (acc. to author)

To investigate the effect of occupational exposure to magnetic fields on bone mineral density, thyroid parameters, and oxidative stress in electricity workers.

Background/further details

The exposure group consisted of 47 workers (mean age 38.4 years) employed in a power station for more than 10 years. Only workers without diseases that may affect bone metabolism were included. The control group consisted also of 47 healthy individuals (mean age 39.1 years) which were not exposed to ionizing and non-ionizing radiation.

Endpoint

endocrine changes: thyroid parameters
bone mineral density; oxidative stress

Exposure

- 50/60 Hz
- magnetic field
- power transmission line
- electrical substation
- occupational

Exposure	Parameters
Exposure 1: LF (< 10 MHz) Exposure duration: mean working period 15.9 years electricity workers	magnetic flux density: 0.53 µT (on work places and walking areas)

Exposure 1

Main characteristics

Frequency	LF (< 10 MHz)
Type	magnetic field
Exposure duration	mean working period 15.9 years
Additional info	electricity workers

Exposure setup

Exposure source	power transmission line, electrical substation

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	0.53 µT	-	-	-	on work places and walking areas

Additional parameter details

No measurements could be performed at the substations for safety reasons.

Exposed system:

human
whole body

Methods Endpoint/measurement parameters/methodology

endocrine changes: thyroid gland size, homogeneity of the thyroid parenchyma, presence of nodules, vascularization (Doppler sonography); serum concentration of the thyroid hormones thyroid stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4) (chemiluminescence kit)
bone mineral density (dual energy x-ray absorptiometry); serum concentrations of the proteins involved in bone metabolism osteoprotegerin (OPG), receptor activator of NF-κB (RANK), and its ligand (RANKL) (ELISA); oxidative stress: total antioxidant status (TAS) and total oxidant status (TOS) in serum (spectrophotometry), oxidative stress index (OSI=TOS/TAS); serum concentrations of alkaline phosphatase and phosphorus (no method stated)

Investigated system:

investigation on living organism

Investigated organ system:

Time of investigation:

after exposure

Main outcome of study (acc. to author)

Bone mineral density was significantly decreased in the vertebrae L1-L4 and femur of the exposure group compared to the control group. Additionally, blood levels of alkaline phosphatase, phosphorus, RANK and RANKL were significantly increased in workers from the study group compared to those from the control group while the level of OPG was significantly decreased. The level of thyroxine was significantly lower in the study group when compared to the control group while the left anteroposterior diameter of the thyroid gland was significantly higher in the study group. Furthermore, the total antioxidant status was significantly decreased and the total oxidant status was significantly increased in exposed workers compared to those from the control group which led to a significantly increased oxidative stress index.
The authors conclude that occcupational long-term exposure to magnetic fields could affect bone and thyroid metabolism and induce oxidative stress.

Study character:

medical/biological study
observational study

Study funded by

Afyon Kocatepe University, Turkey

Hosseinabadi MB et al. (2019): Effect of long-term occupational exposure to extremely low-frequency electromagnetic fields on proinflammatory cytokine and hematological parameters
Zhang Y et al. (2016): Effects of dietary green tea polyphenol supplementation on the health of workers exposed to high-voltage power lines
Lope V et al. (2006): Occupational exposure to ionizing radiation and electromagnetic fields in relation to the risk of thyroid cancer in Sweden