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

Purpose: To test whether exposure to simulated GSM mobile phone signals (91 5 MHz, 2 W kg(-1)) influences the concentration of calcium or calcium signa lling patterns in a human lymphocyte cell line. Materials and methods: The radiofrequency (RF) energy was delivered via a c oaxial applicator to a perfused chamber where cells adherent to a thin glas s 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 assi gned in a blind and randomized fashion. Both continuous wave (CW) and pulse d wave (PW) RF (on both phytohaemagglutanin-activated and unactivated cells ) were studied (with an equal number of sham exposures) on 100 cells per ca tegory (total 800 cells). Results: No significant changes were noted for the following: regression sl ope of calcium fluorescence; mean calcium concentration; number of calcium 'spikes' in each 10 min; or mean height of these 'spikes'. The average freq uency from Fourier spectra of these periods showed significant alteration i n one category only: PW exposure of activated cells. Conclusions : There is no clear indication that RF emissions from mobile ph ones are associated with any changes in calcium levels or calcium signallin g in lymphocytes.