An estimated 285 million Americans subscribe to cell phone service in the United States, according to the National Cancer Institute. As the number grows, so does concern surrounding possible health effects from cell phone use. Numerous scientific studies are examining whether the body's skin and tissues absorb radio frequency energy emitted from cell phones, causing adverse health effects. Scientists agree additional research is needed to study long-term health consequences.
Injury
Drivers who use cell phones are at four times greater risk of having a car accident serious enough to injure the driver, Anne T. McCartt and colleagues explain in a June 2006 issue of the journal of "Traffic Injury Prevention." Phone conversations while driving -- whether hand-held or hands-free -- result in greater distraction, slower reaction times and an increased likelihood of missing traffic signals, the authors add. Cell phone users are also more likely to drive drowsy, drive after drinking, drive 20 miles per hour or more over the speed limit or run a stop sign --- all factors which increase the chance of being in a serious car accident, Kenneth H. Beck and colleagues reported in a study in the November 2007 issue of the "Journal of Safety Research."
Pacemaker Interference
Radio frequency energy emitted from cell phones can interfere with pacemakers, devices implanted in the chest or abdomen to regulate abnormal heart rhythms, the U.S. Food and Drug Administration advises. In particular, cell phones can cause pacemakers to stop emitting the pulses that help control the heart rhythm, ignore the heart's own rhythm or cause irregular pulses to be delivered, the FDA adds. An October 2006 review of scientific studies by Johnson Francis and Michael Niehaus in the "Indian Pacing and Electrophysiology Journal," found about 14 percent of patients with pacemakers experienced interference when cell phones were used close to the pacemaker.
Male Fertility
Scientific studies suggest cell phone use may affect semen quality. A January 2008 article in the journal "Fertility and Sterility" by authors Ashok Agarwal and colleagues linked cell phone use to decreased sperm counts, motility and viability. At greater risk are men who keep carry a cell phone on a belt or in a hip pocket. According to a study by Sarah J. Kilgallon and Leigh Simmons in a March 2005 issue of "Biology Letters," these men display decreased sperm motility compared with men who do not carry cell phones or who carry cell phones elsewhere on the body.
Considerations
Many scientific studies have assessed the health effects of cell phone use on sleep, heart rate, blood pressure, cognitive function, fatigue and headaches. However, findings remain inconclusive. Additionally, the majority of studies have focused on the link between cell phone use and cancer. Both the FDA and World Health Organization say research studies have failed to find a clear association, and, in fact, a large study published in 2010 found no link with brain tumors. According to the WHO, additional research is necessary since phones have only been widely used since the 1990s and many cancers may not develop until years or decades after exposure.
