The science is still out on whether the long-term use of cell phones - which emit electromagnetic radiation when they send and receive signals from towers or WiFi devices - can affect human health. But for people who want to reduce their exposure to this type of energy, the California Department of Public Health has published new guidelines on how to do just that. The guidelines, issued last week, note that "some laboratory experiments and human health studies have suggested the possibility that long-term, high use of cell phones may be linked to certain types of cancer and other health effects." These include brain cancer, tumors of the acoustic nerve and salivary glands, lower sperm count, headaches and effects on learning, memory, hearing, behavior and sleep. The guidelines recommend keeping phones away from the body when they're not in use ... and sleeping with phones away from the bed. People can also reduce their exposure by limiting cell-phone use when the cellular signal is weak; when traveling in a high-speed car, bus or train; to stream audio or video; or to download or upload large files. All of these circumstances cause phones to put out higher-than-normal levels of RF energy. In 2011, the World Health Organization's International Agency for Research on Cancer published a review stating that cell-phone radiation is "possibly carcinogenic." And earlier this year, an Italian court ruled in favor of a plaintiff who argued that his brain tumor was the result of excessive work-related cell-phone use over a 15-year period.