Effects of mobile phone type signals on calcium levels within human leukaemic T-cells (Jurkat cells)

To test whether exposure to simulated GSM mobile phone signals (915 MHz, 2 W x kg(-1)) influences the concentration of calcium or calcium signalling patterns in a human lymphocyte cell line.The radiofrequency (RF) energy was delivered via a coaxial applicator to a perfused chamber where cells adherent to a thin glass coverslip were imaged by laser scanning confocal microscopy. Cell calcium concentration, estimated from Fluo-3 fluorescence, was monitored over two 10-min periods; control followed by exposed/sham, with exposure status assigned in a blind and randomized fashion. Both continuous wave (CW) and pulsed wave (PW) RF (on both phytohaemagglutanin-activated and unactivated cells) were studied (with an equal number of sham exposures) on 100 cells per category (total 800 cells).No significant changes were noted for the following: regression slope of calcium fluorescence; mean calcium concentration; number of calcium 'spikes' in each 10 min; or mean height of these 'spikes'. The average frequency from Fourier spectra of these periods showed significant alteration in one category only: PW exposure of activated cells.There is no clear indication that RF emissions from mobile phones are associated with any changes in calcium levels or calcium signalling in lymphocytes.