Posted on Nov 13, 2015, 6 a.m.
Smartphones, tablets, and laptops can reflect ultraviolet light from the sun and may indirectly increase users' exposure to the cancer-causing wavelengths.
An often under-recognized health concern, incidences of skin cancer have been on the rise. Ultraviolet (UV) radiation exposure has been associated with approximately 90% of nonmelanoma skin cancers. Most often addressed in terms of direct exposure, UV radiation also is experienced via indirect sources, such as reflected UVB. Mary E. Logue, from the University of New Mexico (New Mexico, USA), and colleagues completed a small observational study to assess UV exposure via light reflected from various personal electronic devices. Setting up a mannequin head wearing a UVA/B light meter and facing it toward a standard musician’s sheet stand, the team recorded UV readings for an hour of exposure, from 11 AM to noon, using a magazine, an iPhone5, various iPad models, two Macbook laptops and a Kindle e-reader. In the first trial the devices were 16.5 inches from the UV sensor. For the second, they were secured 12.25 inches away. The devices and the UV sensor were angled to mimic an adult looking down at the handheld device. In the first trial, when the devices were further away from the mannequin, an open magazine increased UV dosage exposure by 46% compared to the sheet stand alone, an iPad2 increased exposure by about 85% and an 11-inch Macbook increased UV exposure by 75%. Only the second trial, with devices held closer to the mannequin's “face,” included the iPhone5, which increased UV exposure by 36%. The lead investigator warns that: ““These devices are generally used for communication or entertainment, so it can be easy to overlook their reflective properties unless you happen to catch the glare off a screen.”
Mary E. Logue, Barrett J. Zlotoff. “Reflections on smart phones, tablets, and ultraviolet (UV) light: Should we worry?” J Am Acad Dermatology, Vol 73, No 3, Pages 526-528.