To study the synergistic DNA damage effects in human lymphocytes induced by 1.8 GHz radiofrequency field irradiation with four chemical mutagens (mitomycin C (DNA crosslinker), bleomycin (radiomimetic agent), methyl methanesulfonate (alkylating agent), and 4-nitroquinoline-1-oxide (UV-mimetic agent)).
Cells were divided into four groups: 1) sham-control group, 2) radiofrequency field irradiation group, 3) chemical exposure group, 4) radiofrequency field irradiation + chemical exposure group. Three combinative exposure ways were: 1) radiofrequency field irradiation before chemical exposure, 2) radiofrequency field irradiation together with chemical exposure, and 3) radiofrequency field irradiation after chemical exposure.
Exposure duration: continuous for 2 h
|Exposure duration||continuous for 2 h|
|Chamber||The exposure setup was based on two R18 rectangular waveguide chambers, one for RF and one for sham exposure that were blindly activated by a computer controlled signal unit.|
|Setup||Cells were put in 35-mm dishes and placed into the two waveguide chambers (TEM cells).|
|Sham exposure||A sham exposure was conducted.|
|Additional info||The lymphocytes were divided into four groups: sham control, RF exposure, chemical exposure, and RF + chemical exposure group.|
The data showed no difference of DNA damage indices between radiofrequency field exposed group and control group at 0 and 21 h incubation after exposure.
There were significant differences of DNA damage indices between "mitomycin C group" and "radiofrequency field irradiation + mitomycin C co-exposure group" at 0 and 21 h incubation after treatment.
Also the significant difference of DNA damage indices between "4-nitroquinoline-1-oxide group" and "radiofrequency field irradiation + 4-nitroquinoline-1-oxide co-exposure group" at 0 and 21 h incubation after treatment was revealed.
The DNA damage in "radiofrequency field irradiation + bleomycin co-exposure groups" and "radiofrequency field irradiation + methyl methanesulfonate co-exposure groups" was not significantly increased, as compared with corresponding "bleomycin" and "methyl methanesulfonate groups".
The findings indicated that 1.8 GHz radiofrequency field irradiation for 2 h did not induce the human lymphocyte DNA damage effects in vitro, but it could enhance the human lymphocyte DNA damage effects induced by mitomycin C and 4-nitroquinoline-1-oxide. The synergistic DNA damage effects of 1.8 GHz radiofrequency field irradiation with bleomycin or methyl methanesulfonate were not obvious.