Intermediate frequency magnetic fields generated by an induction heating (IH) cooktop do not affect genotoxicities and expression of heat shock proteins.
OBJECTIVE
The aim of this study is to evaluate the effects of intermediate frequency (IF) fields generated by induction heating (IH) cooktops from the perspective of cellular genotoxicity and stress responses.


METHODS
We evaluated the effects of exposure to 23 kHz magnetic fields at 6.05 mT(rms) for 2 h on cellular genotoxicity and stress responses in vitro. The maximum output power in most IH cooktops is at this frequency. The magnetic flux density is approximately 1000 times higher than the reference level in the International Commission on Non-ionising Radiation Protection (ICNIRP) guidelines. For assessment of genotoxicity, we studied cell growth, comet assay, micronucleus formation and hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene mutation. Heat shock protein (Hsp) 27, 70, 105 and phosphorylated Hsp27 were evaluated as indicators of the stress responses.


RESULTS
We did not detect any effects of the IF magnetic fields on cell growth, comet assay, micronucleus formation, HPRT gene mutation, expression of phosphorylated Hsp27, or nuclear translocation of Hsp27, 70 or 105.


CONCLUSIONS
Our results indicate that exposure to an IF magnetic field at 6.05 mT(rms) for 2 h does not cause detectable cellular genotoxicity, and does not induce detectable cellular stress.
Department of Radiological Life Sciences, Division of Medical Life Sciences, Graduate School of Health Sciences, Hirosaki University, Hirosaki, Japan.
Tomonori
T
Sakurai
Tomoko
T
Kiyokawa
Kazuki
K
Kikuchi
Junji
J
Miyakoshi
D000818:Animals; D016466:CHO Cells; D045744:Cell Line, Tumor; D020552:Comet Assay; D003296:Cooking / Q000295:instrumentation; D006224:Cricetinae; D003412:Cricetulus; D004249:DNA Damage; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006361:Heating / Q000295:instrumentation; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics; D008280:Magnetics / Q000295:instrumentation; D015162:Micronucleus Tests; D009154:Mutation; D013312:Stress, Physiological / Q000528:radiation effects
D006360:Heat-Shock Proteins; D007041:Hypoxanthine Phosphoribosyltransferase