Assessment of Health Risks of Intermediate Frequency Magnetic Fields

Abstract

Health effects of electromagnetic fields have been studied mainly focusing on extremely low frequency magnetic fields and radio frequency fields. Less attention has been paid to intermediate frequency magnetic fields (IF MFs) even though number of applications is increasing and information on potential health effects is sparse. We are conducting a series of studies to assess the exposure to IF MFs and the consequences of exposure.

Based on our measurements near electronic article surveillance (EAS) devices, cashiers are a group with exceptional IF MF exposure. Reproductive health effects are studied among female cashiers in an epidemiological study.

Behavioural and cognitive effects in mice exposed to 7.5 kHz MF were assessed. Post-mortem histochemical analyses were also performed. Blood cell samples from animals exposed to IF MFs are being assayed for genotoxicity. Male fertility indicators were measured in exposed mice. A behavioural teratology study is being conducted: mice are exposed to IF MFs in utero and the pups are tested for cognitive effects.

In vitro studies were performed with rat primary astrocytes. Cells were exposed to a vertical 7.5 kHz MF. DNA damage and DNA repair, and micronucleus formation were analyzed. To assess joint effects, genetic damage was induced with two known genotoxic agents. Selected endpoints were measured immediately after exposure and 36 days after exposure to assess induced genomic instability.

No adverse effects of IF MFs were observed on fertility in male mice or genotoxicity in cell cultures. However, interesting findings indicating protective effects were observed, which need to be confirmed in further studies. The behavioural studies suggested impaired spatial learning and memory. The behavioural teratology study, in vivo genotoxicity and the epidemiological study are still ongoing. Assessment of health risks will be done when all results are available.