Background: Exposure to an increasing amount of extremely low-frequency magnetic fields (MFs) causes some adverse effects. Considering a direct association between the sizes and numbers of argyrophilic nucleolar organizer regions (AgNORs) and cell proliferation, this study was conducted to evaluate the effect of 50-Hz MFs on the AgNORs of bone marrow (BM) cells.
Methods: Eighty male rats were randomly divided into four exposed groups and one control group. The exposed groups received 50-Hz MFs with magnetic flux densities of 1, 100, 500, and 2000 µT two hours a day for two months. BM cells were aspirated from sacrificed rats’ femoral bones, smeared on glass slides, and then stained with silver nitrate for AgNORs. The area (AA), length (AL), and number (AN) of AgNORs were calculated by a microscope equipped with a camera and Scion Image software in 100 BM cells of each rat. The mean of AA, AL, and AN was computed for each group.
Results: AA, AL, and AN significantly reduced in the 1 µT group compared with 2000 µT and control groups. Eventually, there was a nonlinear relationship between the effect of 50-Hz MFs and magnetic flux densities.
Conclusion: Overall, 50-Hz MFs with a magnetic flux density of 1 µT reduced AgNORs in BM cells. However, 100, 500, and 2000 µT did not affect AgNORs. Therefore, 50-Hz MFs with low density may suppress BM cell proliferation.