Effects of exposure of the ear to GSM microwaves: in vivo and in vitro experimental studies

• Published in: International journal of audiology 2004-10, Vol.43 (9), p.545-554
• Main Authors: Aran, Jean-Marie, Carrere, Nathalie, Chalan, Yan, Dulou, Pierre-Emmanuel, Larrieu, Sophie, Letenneur, Luc, Veyret, Bernard, Dulon, Didier
• Format: Article
• Language: English
• Subjects: Adverse effects; Analysis of Variance; Animals; Animals, Newborn; Auditory Pathways; Cell Phone; Cochlea; Evoked Potentials, Auditory - radiation effects; Female; Guinea Pigs; Hair Cells, Auditory - radiation effects; Hearing; In Vitro Techniques; Microwaves - adverse effects; Mobile telephones; Organ of Corti - radiation effects; Otoacoustic Emissions, Spontaneous - radiation effects; Radiometry; Rats
• ISSN: 1499-2027; 1708-8186
• DOI: 10.1080/14992020400050069

The effects of mobile phone (GSM) microwaves on the ears of guinea pigs were investigated in two in vivo experiments and one in vitro experiment. In the first experiment, three groups of eight guinea pigs had their left ear exposed for 1 h day, 5 days week, for 2 months, to GSM microwaves (900 MHz, GSM modulated) at specific absorption rates (SARs) of 1, 2 and 4 W kg respectively, and a fourth group was sham-exposed. Distortion-product otoacoustic emissions (DPOAEs) were measured for each ear before exposure, at the end of the 2-month exposure period, and 2 months later. In the second experiment, the same protocol was applied to eight sham-exposed and 16 exposed guinea pigs at 4 W kg, but the auditory brainstem response (ABR) thresholds were monitored. Repeated-measures ANOVA showed no difference in DPOAE amplitudes or in ABR thresholds between the exposed and non-exposed ears and between the sham-exposed and exposed groups. In the course of the second experiment, acute effects were also investigated by measuring once, in all animals, ABR thresholds just before and just after the 1-h exposure: no statistically significant difference was observed. In vitro, the two organs of Corti (OCs) of newborn rats (n = 15) were isolated and placed in culture. For each animal, one OC was exposed for 24-48 h to 1 W kg GSM microwaves, and the other was sham-exposed. After 2-3 days of culture, all OCs were observed under light microscopy. They all appeared normal to naive observers at this stage of development. These results provided no evidence that microwave radiation, at the levels produced by mobile phones, caused damage to the inner ear or the auditory pathways in our experimental animals. Sumario Se investigaron los efectos de las micro-ondas (GSM) de los teléfonos móviles sobre los oídos de los cobayos en dos experimentos in vivo y en uno in vitro. En el primer experimento, 3 grupos de 8 cobayos (GP) tuvieron su oído izquierdo expuesto durante 1 hora día, 5 días semana, por 2 meses, a micro-ondas GSM (900 MHz, con modulación GSM) con Tasas de Absorción Específica (SAR) de 1, 2 y 4 W kg, respectivamente, y un cuarto grupo tuvo una exposición fingida. Se midieron emisiones otoacústicas por productos de distorsión (DPOAE) antes, al final del período de exposición de 2 meses y 2 meses después. En el segundo experimento, se aplicó el mismo protocolo con 8 exposiciones fingidas y 16 GP expuestos a 4 W kg, pero se monitorizaron los umbrales de las Respuestas Auditivas del