This PubMed-listed in vitro study tested whether 1800 MHz RF-EMF exposure can modify chemically induced DNA damage in mouse embryonic fibroblasts under standardized, non-thermal conditions. The authors report RF-EMF alone did not produce detectable DNA damage and did not significantly increase damage from hydrogen peroxide, 4-nitroquinoline-1-oxide, or cadmium. However, co-exposure with hexavalent chromium (Cr(VI)) was reported to synergistically increase DNA damage in the comet assay, which the authors interpret as possible selective exacerbation of Cr(VI)-induced genotoxicity requiring further investigation.