To　investigate　the　potential　adverse　effects　of　mobile　phone　radiation,　we　studied　reactive　oxygen　species　(ROS),　DNA　damage　and　apoptosis　in　mouse　embryonic　fibroblasts　(NIH/3T3)　after　intermittent　exposure　(5　min　on/10　min　off,　for　various　durations　from　0.5　to　8　h)　to　an　1800-MHz　GSM-talk　mode　electromagnetic　radiation　(EMR)　at　an　average　specific　absorption　rate　of　2　W/kg.　A　2＇,7＇-dichlorofluorescin　diacetate　fluorescence　probe　was　used　to　detect　intracellular　ROS　levels,　immunofluorescence　was　used　to　detect　gamma　H2AX　foci　as　a　marker　for　DNA　damage,　and　flow　cytometry　was　used　to　measure　apoptosis.　Our　results　showed　a　significant　increase　in　intracellular　ROS　levels　after　EMR　exposure　and　it　reached　the　highest　level　at　an　exposure　time　of　1　h　(p　＜　0.05)　followed　by　a　slight　decrease　when　the　exposure　continued　for　as　long　as　8　h.　No　significant　effect　on　the　number　of　gamma　H2AX　was　detected　after　EMR　exposure.　The　percentage　of　late-apoptotic　cells　in　the　EMR-exposed　group　was　significantly　higher　than　that　in　the　sham-exposed　groups　(p　＜　0.05).　These　results　indicate　that　an　1800-MHz　EMR　enhances　ROS　formation　and　promotes　apoptosis　in　NIH/3T3　cells.