Exposure to blue light decreases blood pressure, reducing the risk of developing cardiovascular disease, a new study from the University of Surrey and Heinrich Heine University Dusseldorf in collaboration with Philips reports. During this study, published in the European Journal of Preventative Cardiology, participants were exposed to 30minutes of whole-body blue light at approximately 450 nanometres, a dose comparable to daily sunlight — followed by exposure to a control light on a different day. Visible blue light, as opposed to ultraviolet (UV) light, is not carcinogenic.