Laptop PCs that use Wi-Fi could affect male fertility by damaging the sperm and fragmenting DNA, the world's first study into portable computers has discovered. Men who rest the PC on their laps - rather than on a desk - are much more likely to be affected, say researchers from Nascentis, a reproductive medical centre in Cordoba, Argentina. Wi-Fi radiation affects sperm motility, or movement, and damages the DNA. Researchers discovered that virtually every laptop user had damaged sperm when samples were compared with those from men who didn't use a laptop and Wi-Fi. The researchers advise men only to use a laptop on a desk, and not on their knees and legs. The findings are controversial. Health agencies have maintained that Wi-Fi radiation has very low emissions, and even a year in a 'hotspot' is equivalent to 20-minutes mobile phone usage. (Source: Digital Journal, 26 July, 2010. Website: http://www.digitaljournal.com/article/295085).