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The influence of low-frequency magnetic field on plasma antioxidant capacity and heart rate.

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Ciejka EB, Goraca A · 2009

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Magnetic field exposure duration matters: 14 days of 40 Hz fields slowed heart rate and altered cellular antioxidant defenses in rats.

Plain English Summary

Summary written for general audiences

Researchers exposed rats to 40 Hz magnetic fields (7 mT strength) for different durations and measured heart rate and antioxidant levels in blood. They found that 14 days of exposure slowed heart rate and changed the body's antioxidant defenses, with effects varying based on daily exposure time (30 vs 60 minutes). The study shows that magnetic field exposure duration affects cardiovascular function and cellular protection systems.

Why This Matters

This research demonstrates that extremely low frequency magnetic fields can measurably alter cardiovascular function and cellular antioxidant systems. The 7 mT exposure level used here is significantly higher than typical household magnetic fields (which range from 0.01-0.2 mT), but it's within the range of occupational exposures for some workers near heavy electrical equipment. What makes this study particularly significant is that it shows duration-dependent effects - the same magnetic field produced different biological responses depending on whether animals were exposed for 30 or 60 minutes daily. The finding that heart rate decreased after 14 days of exposure adds to growing evidence that ELF magnetic fields can influence cardiovascular function. The changes in antioxidant capacity suggest these fields may be creating oxidative stress in cells, forcing the body to respond with protective mechanisms.

Exposure Details

Magnetic Field
7 mG
Source/Device
40 Hz
Exposure Duration
30 and 60 minutes

Exposure Context

This study used 7 mG for magnetic fields:

Building Biology guidelines are practitioner-based limits from real-world assessments. BioInitiative Report recommendations are based on peer-reviewed science. Check Your Exposure to compare your own measurements.

Where This Falls on the Concern Scale

Study Exposure Level in ContextStudy Exposure Level in ContextThis study: 7 mGExtreme Concern - 5 mGFCC Limit - 2,000 mGEffects observed in the Extreme Concern rangeFCC limit is 286x higher than this level
A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 40 Hz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 40 HzCell phones~1 GHzWiFi2.4 GHz5G mm28 GHzLogarithmic scale

Study Details

The aim of the study was to check whether a time-variable magnetic field of constant frequency and induction affects the heart rate and plasma antioxidant capacity.

The tests were performed on Spraque-Dawley rats exposed to the magnetic field of the following param...

A significant decrease of the heart rate was observed after 14 days of exposure. A variable magnetic...

The exposure time affects heart rate, plasma antioxidant capacity and the organism defense ability against free radicals.

Cite This Study
Ciejka EB, Goraca A (2009). The influence of low-frequency magnetic field on plasma antioxidant capacity and heart rate. Wiad Lek. 62(2):81-86, 2009.
Show BibTeX
@article{eb_2009_the_influence_of_lowfrequency_335,
  author = {Ciejka EB and Goraca A},
  title = {The influence of low-frequency magnetic field on plasma antioxidant capacity and heart rate.},
  year = {2009},
  
  url = {https://europepmc.org/article/med/20141054},
}
PubMed: 20141054

Cited By (12 papers)

Quick Questions About This Study

Yes, magnetic field exposure can affect heart rate. A 2009 study found that rats exposed to 40 Hz magnetic fields for 14 days showed significantly slower heart rates, demonstrating that electromagnetic field exposure can influence cardiovascular function in measurable ways.
Low frequency magnetic fields can affect cellular protection systems. Research shows 40 Hz magnetic field exposure changes the body's antioxidant defenses, either increasing or decreasing them depending on daily exposure duration, which impacts how cells defend against free radical damage.
Studies suggest 40 Hz electromagnetic fields may impact heart function. Research found that 14-day exposure to 40 Hz magnetic fields at 7 mT strength caused measurable changes in heart rate and cellular antioxidant systems in laboratory animals.
EMF exposure duration significantly affects biological responses. A study showed that 30-minute daily magnetic field exposure increased antioxidant defenses, while 60-minute exposure decreased them, proving that exposure time is a critical factor in determining health effects.
Magnetic field exposure can either increase or decrease your body's antioxidant capacity. Research demonstrates that 40 Hz magnetic fields affect antioxidant defense systems differently based on daily exposure time, altering how your cells protect themselves from oxidative damage.