In March of 2011, a magnitude 9.0 earthquake and subsequent 14 meter high tsunami caused major damage to the Fukushima Daiichi nuclear power plant in Japan. The release of radiation, along with other uncontrolled releases elsewhere, revealed the necessity of a portable high throughput minimally invasive biological dosimetry modality. Immediate and early radiation effects on vasculature could be used as a dosimetry modality. To test whether non-coronary vasculature exhibited transient perturbation in barrier function, video microscopy studies and electric cell-substrate impedance sensing (ECIS) technology were used to probe very subtle changes in primary human vascular endothelium. In our studies, human umbilical vein endothelial cell (HUVEC) monolayers exhibited a transient, significant decrease (