“Don’t go out in the sun in the middle of the day! Put your sunglasses on!” More and more people are heeding tips like these in order to protect themselves against the sun’s harmful ultraviolet (UV) rays. However, a few years ago Swiss scientists from the University of Lausanne1 suggested that such measures simply aren’t enough to counteract the biggest UV problem: scattered radiation – and we’re particularly at risk at times when we normally don’t wear our sunglasses. This could be while taking a stroll along a leafy shopping street, or when gardening on a cloudy day.
It’s true that direct UV radiation is normally stronger than scattered radiation, but over the course of the year we are exposed to considerably more UV through scattered radiation than direct sunlight. According to the findings of the Swiss researchers, the direct incident light we’re exposed to when we spend time out in the sun accounts for just 20 percent of our annual UV exposure. Scattered radiation can be responsible for up to 80 percent of our yearly dose, and we cannot avoid it completely – even when we keep to the shade.