Raman investigation of human peripheral blood monocyte cells exposed to 1.8 GHz electromagnetic fields

In latest years, investigations about morphological and biochemical modifications occurring in lympho-monocyte cells from peripheral blood of healthy donors after exposure to non-ionizing electromagnetic fields have provided controversial results [1]. Therefore, this issue is still largely investigated, expecially by in vitro experiments, where some experimental parameters can be easily controlled. In this study, we exposed whole blood from healthy donors to electromagnetic fields at 1.8 GHz and intensity of 200 V/m for different times ranging from 1 to 20 hours. The exposure process occurred inside a home-made reverberation chamber, which provides a controlled electromagnetic field intensity and temperature [2]. After exposure, lympho-monocyte cells have been isolated from peripheral blood by density gradient centrifugation methods. Respirometric tests highlighted an increase of the oxygen consumption in lympho-monocyte population after exposure. Bright filed microscopy analysis based on the estimation of the ratio of number of altered and healthy cells after staining with May-Grünwald-Giemsa method showed that a cell morphological alteration occurred after exposure at electromagnetic field, independently on the exposure time. Raman spectra of control and exposed single monocytes were measured with the 514.5 nm laser excitation line and the average spectra, calculated from about 20 individual cells for each type of sample, were compared. Each single spectrum has been deconvolved by means of Voigt functions and the intensity of some specific peaks, related to vibrational modes characteristic of DNA (785, 1092 and 1578 cm-1) and proteins (1003 and 1615 cm-1), have been considered for comparison purposes. In particular, the intensity ratios I785/I1003, I1092/I1003 and I1578/I1615 is significantly larger in control cells with respect to exposed ones and the difference of such intensity ratio between control and exposed cells decreases with decreasing exposure time. Such results suggest a radiation-induced biochemical modifications occurring in nucleic acids larger than in proteins and proportional to exposure time. References [1] E. Jirillo et al., Adv. Res. 2, 478 (2014) and references therein. [2] P.F. Biagi et al, J. Instr. 6, T07002 (2011).