There is no evidence that cellphones can negatively affect human health, according to a review by the U.K.’s Health Protection Agency (HPA). The agency looked at hundreds of significant studies that examined the effects of exposure to radiofrequency (RF) electromagnetic fields, the kind produced by cellphones, TV and radio transmitters, and Wi-Fi. The review, which updated a previous one done in 2003, found no evidence that cellphones can cause cancer, including brain tumors. There was also no link between exposure to RF fields below the international guidelines and infertility or cardiovascular problems. In spite of the clean bill of health for cellphones, committee members highlighted the need for ongoing monitoring. Cellphones have only been in use since the 1990s, so there is little known about the risks beyond 15 years. "One can't know what the long-term consequences are of something that has been around for only a short period,” said Anthony Swerdlow, who chaired the review group. The report also suggested that more research be done on newer technologies like smart electric meters and airport security scanners. Children should also be discouraged from using cellphones excessively, although more work was needed on whether cellphones can affect children’s behavior.