Cytogenetic studies in human blood lymphocytes exposed in vitro to radiofrequency radiation at a cellular telephone frequency (835.62 MHz, FDMA)

Freshly collected peripheral blood samples from four healthy human voluntee rs were diluted with RPMI 1640 tissue culture medium and exposed in sterile T-75 tissue culture flasks in vitro for 24 h to 835.62 MHz radiofrequency (RE) radiation, a frequency employed for customer-to-base station transmiss ion of cellular telephone communications. An analog signal was used, and th e access technology was frequency division multiple access (FDMA, continuou s wave). A nominal net forward power of 68 W was used, and the nominal powe r density at the center of the exposure flask was 860 W/m(2). The mean spec ific absorption rate in the exposure flask was 4.4 or 5.0 W/kg. Aliquots of diluted blood that were sham-exposed or exposed in vitro to an acute dose of 1.50 Gy of gamma radiation were used as negative or positive controls. I mmediately after the exposures, the lymphocytes were stimulated with a mito gen, phytohemagglutinin, and cultured for 48 or 72 h to determine the exten t of genetic damage, as assessed from the frequencies of chromosomal aberra tions and micronuclei. The extent of alteration in the kinetics of cell pro liferation was determined from the mitotic indices in 48-h cultures and fro m the incidence of binucleate cells in 72-h cultures. The data indicated no significant differences between RF-radiation- and sham-exposed lymphocytes with respect to mitotic indices, incidence of exchange aberrations, excess fragments, binucleate cells, and micronuclei, In contrast, the response of the lymphocytes exposed to gamma radiation was significantly different fro m both RF-radiation- and sham-exposed cells for all of these indices. Thus, under the experimental conditions tested, there is no evidence for the ind uction of chromosomal aberrations and micronuclei in human blood lymphocyte s exposed in vitro for 24 h to 835.62 MHz RF radiation at SARs of 4.4 or 5. 0 W/kg. (C) 2001 by Radiation Research Society.