Budak, G. G.; Muluk, N. B.; Ozturk, G. G.; Budak, B.; Apan, A.; Seyhan, N., and Sanli, C. Effects of GSM-like radiofrequency on distortion product otoacoustic emissions in pregnant adult rabbits. Clin Invest Med. 2009; 32(2):E112-6.
Possible effects of 1800 MHz GSM-like radiofrequency radiation (RFR) on cochlear function in pregnancy have not been studied yet. Distortion product otoacoustic emissions (DPOAEs) can be assessed as indicators of cochlear status.
The objective of this experiment was to study potential effects of 1800 MHz GSM-like RFR on cochlear functions of pregnant rabbits by DPOAEs.
Eighteen 13-month old non-pregnant and eighteen 13-month old pregnant New Zealand White rabbits were randomly divided into four groups: 9 pregnant rabbits and 9 non-pregnant rabbits were exposed to 1800 MHz GSM-like RFR 15 min daily for 7 days. A total of 9 pregnant rabbits and 9 non-pregnant rabbits were not exposed to RFR. Cochlear functions were examined by DPOAEs at 1.0 – 8.0 kHz.
There was no difference in DPOAE amplitudes between RFR exposed and RFR unexposed pregnant rabbits in all groups except 2.0 KHZ. In the RFR exposed non-pregnant rabbits, DPOE amplitudes at 1.0-4.0 kHz were lower and at 6.0-8.0 kHz – no different from the unexposed non-pregnant rabbits.
Harmful effects of GSM-like RFR were lower in the pregnant animals compared to the non-pregnant group. Increased endolymph production due to estrogen levels and higher corticosteroid levels may protect the inner ear from hazardous effects of RFR in pregnancy.
The authors have concluded that exposure to GSM-like RFR may result in decreases in DPOAE amplitudes. In pregnancy, increased inner ear volume may reduce the damage. Because this study shows only early effects of GSM-like RFR, future studies of late RFR effects are needed.