en Radiation Biology Radiation Biology تحقيق بديع Original Research <span style="font-weight: bold">Background: </span>Rapidly increasing possibilities of exposure to environmental extremely low-frequency electromagnetic fields (ELF-EMF) have become a topic of worldwide investigation. Epidemiological and laboratory studies suggest that exposure to ELF-EMF may increase cancer risk therefore assessment of chromosomal damage in various cell lines might be of predictive value for future risk estimation. <span style="font-weight: bold">Materials and Methods:</span> Primary cultures of fibroblasts from human skin biopsy were exposed to continuous extremely low-frequency electromagnetic fields (3, 50 and 60 Hz, sinusoidal, 3h, and 4 mT). Also immortalized cell lines, SW480, MCF-7 and 1321N1 were exposed to continuous ELF-EMF (50 Hz, sinusoidal, 3 h, 4 mT). Metaphase plates were prepared according to standard methods and stained in 5% Giemsa solution. Chromosomal aberrations of both chromosome and chromatid types were scored to evaluate the effects of ELF-EMF on primary or established cell lines. <span style="font-weight: bold">Results:</span> Results indicate that by increasing the frequency of ELF-EMF, chromosomal aberrations were increased up to 7-fold above background levels in primary human fibroblast cells. In addition, continuous exposure to a 50 Hz electromagnetic field led to a significant increase in chromosomal aberrations in SW480, MCF-7 and 1321N1 cell lines compared to sham control. <span style="font-weight: bold">Conclusion: </span>Results obtained indicate that ELF-EMF has the potential for induction of chromosomal aberrations in all cell types. Iran. J. Radiat. Res., 2010 8 (1): 25-29 ELF-EMF, chromosomal aberrations, continuous exposure, human fibroblasts, cancer cell lines. 25 29 http://ijrr.com/browse.php?a_code=A-10-1-347&slc_lang=en&sid=1 S.S. Seyyedi 790031947532846001815 790031947532846001815 No H. Mozdarani mozdarah@modares.ac.ir 790031947532846001941 790031947532846001941 Yes M. Rezaei Tavirani 790031947532846001942 790031947532846001942 No S. Heydari 790031947532846001943 790031947532846001943 No