Medical/biological study (experimental study)

Extremely low-frequency magnetic field decreased calcium, zinc and magnesium levels in costa of rat med./bio.

By: Ulku R, Akdag MZ, Erdogan S, Akkus Z, Dasdag S

Published in: Biol Trace Elem Res 2011; 143 (1): 359-367

Aim of study (acc. to author)

To study possible changes in some elements (e.g. magnesium, zinc, calcium) in the costa of rats exposed to long-term extremely low frequency magnetic fields.

Background/further details

21 rats were divided into three groups: sham exposure group (n=7) and two exposure groups (n=14). Five ribs of each animal were excised.

Endpoint

levels of magnesium, calcium, phosphorus, zinc, iron, copper in the costa

Exposure

- 50/60 Hz
- magnetic field

Exposure	Parameters
Exposure 1: 50 Hz Exposure duration: continuous for 2 h/day, 7 days/week during 10 months	magnetic flux density: 100 µT (standard safety limit for public exposure) magnetic flux density: 500 µT (standard safety limit for occupational exposure) I = 0.12 A for B = 100 µT I = 0.5 A for B = 500 µT

Exposure 1

Main characteristics

Frequency	50 Hz
Type	magnetic field
Exposure duration	continuous for 2 h/day, 7 days/week during 10 months

Exposure setup

Exposure source	Helmholtz coils
Setup	pair of Helmholtz coils with a diameter of 25 cm and 225 turns of 1 mm diameter insulated copper wire placed in a 130 cm x 65 cm x 80 cm Faraday cage, 25 cm apart; rats placed in a Plexiglas cage inside the coil system
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	100 µT	-	measured	-	standard safety limit for public exposure
magnetic flux density	500 µT	-	measured	-	standard safety limit for occupational exposure
cf. remarks	-	-	-	-	I = 0.12 A for B = 100 µT
cf. remarks	-	-	-	-	I = 0.5 A for B = 500 µT

Additional parameter details

50 Hz stray fields during sham exposure: 0.1 µT static earth's magnetic field parallel to the exposure field: 14 µT static earth's magnetic field perpendicular to the exposure field: 34 µT

Exposed system:

Methods Endpoint/measurement parameters/methodology

levels of magnesium, calcium, phosphorus, zinc, iron, copper in the costa (atomic absorption spectrophotometry and UV spectrophotometry)

Investigated system:

costa homogenates

Investigated organ system:

muscular/skeletal system

Time of investigation:

after exposure

Main outcome of study (acc. to author)

Calcium levels decreased in the 500 µT exposure group in comparison to the sham exposure group. Statistically significant decreases were found in magnesium and zinc levels in the 500 µT exposure group in comparison to sham exposure and 100 µT exposure groups. No significant differences were found between groups in terms of the levels of phosphorus, copper and iron.
The authors conclude that long-term extremely low frequency magnetic field exposure can affect the bone metabolism in rats by changing the levels of some important elements such as calcium, zinc and magnesium.

Study character:

medical/biological study
experimental study
full/main study
blind study

Study funded by

not stated/no funding

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