High Energy, Ultrashort Pulse Green Laser-Light Exposure of Cultured Human Cells Yields Evidence of DNA Damage

Abstract

Abstract : The use of laser light for targeting devices and weapons has sharply increased the likelihood that aircrew and support personnel will be exposed to laser light during operations. The increased potential for exposure of humans highlights the need for scientifically-based safety standards for laser exposure at the ultrashort pulse lengths. Current safety standards are largely extrapolations of exposure limits at longer pulse lengths using a minimal visible lesion endpoint in the Rhesus monkey retinal model. A non-animal model for assessing laser-light damage to tissue, particularly human, is necessary for obvious scientific, political, and fiduciary reasons. We assessed the sublethal insult to human cells using a tissue culture system for specific genes that have been shown to be important in several biological processes that could lead to cancer or cell death. Using the CAT-Tox (L) (Xenometrix, Inc.) assay, it appears that green (532 nm), picosecond pulses of laser light is sensed and induces several stress response genes, including FOS, a proto-oncogene, in a roughly dose dependent fashion. Numerous other genes were also induced harbingering the presence of DNA damage. This approach provides insight into a more global methodology for characterizing environmental stressors via genetic profiling.