[6] Why aren’t the results of the studies consistent?
Scientists have had to assess how much RF energy people have been exposed to by interviewing individuals involved in a particular study about their cellular telephone habits (including frequency of use and duration of calls). Because of this, the accuracy of the data collected is subject to the memory of the people interviewed. Recently, however, RF-energy-measurement meters have been developed that will accurately measure RF energy exposure (1).
Additionally, cellular telephones have only been widely available for a relatively short period of time (since the 1990s), and cellular technology continues to change (1). For example, older studies evaluated RF exposure from analog telephones; today, most cellular telephones use digital technology. (Analog and digital telephones operate at different frequencies and power levels.) Another new technology is Bluetooth, a wireless technology that allows devices, such as cellular telephones and headsets, to communicate with each other using short-range radio frequency.
Furthermore, brain tumors develop over many years. Scientists have been unable to follow cellular telephone users consistently for the amount of time it might take for a brain tumor to develop (1).
Although research has not consistently demonstrated a link between cellular telephone use and cancer, scientists still caution that more research needs to be done before conclusions can be drawn about the risk of cancer from cellular telephones (1).
[7] Do children have a higher risk of developing cancer due to cellular telephone use than adults?
There is no evidence that cellular telephone use poses more of a threat to children than to adults (2). However, no study populations to date have included children, who are increasingly heavy users of cellular telephones and are likely to accumulate many years of exposure during their lives (1).
In addition, children are at greatest risk from agents known to cause brain and nervous system cancers because their nervous systems are still developing. If RF energy from cellular telephones is proven to cause cancer, researchers would expect children to be more susceptible than adults. Again, however, there is no evidence of this to date (1).
[8] What can cellular telephone users do to reduce their exposure to RF?
The Food and Drug Administration (FDA) has suggested some steps that cellular telephone users can take if they are concerned about potential health risks from cellular telephones:
Reserve the use of cellular telephones for shorter conversations, or for when a conventional phone is not available.
Switch to a type of cellular telephone with a hands-free device that will place more distance between the antenna and the phone user.
Additionally, the Federal Communications Commission (FCC), which regulates interstate and international communications by radio, television, wire, satellite, and cable, provides consumers with information on human exposure to RF energy from cellular telephones and other devices at
http://www.fcc.gov/oet/rfsafety on the Internet. This Web page allows consumers to find information about the specific absorption rate (SAR) of cellular telephones produced and marketed within the last 1 to 2 years. The SAR corresponds to the relative amount of RF energy absorbed into the head of a cellular telephone user. Consumers can access this information using the phone’s FCC ID number, which is usually located on the case of the phone.
[8] Can cellular telephones interfere with medical equipment?
Yes. Cellular telephones can interfere with pacemakers (electrical devices, implanted in the chest, that stimulate or steady the heartbeat), implanted defibrillators (electrical devices that restore a normal heartbeat by applying an electrical shock to the heart), and hearing aids. However, standards have been established that will allow manufacturers to ensure that cardiac pacemakers and defibrillators are safe from cellular telephone RF (2).
Selected References
Ahlbom A, Green A, Kheifets L, et al. Epidemiology of health effects on radiofrequency exposure. Environmental Health Perspectives 2004; 112(14):1741–1754.
Food and Drug Administration (2003). Cell Phone Facts: Consumer Information on Wireless Phones. Retrieved May 10, 2005, from
http://www.fda.gov/cellphones/qa.html.
Muscat JE, Malkin MG, Thompson S, et al. Handheld cellular telephone use and risk of brain cancer. Journal of the American Medical Association 2000; 284(23):3001–3007.
Inskip PD, Tarone RE, Hatch EE, et al. Cellular-telephone use and brain tumors. New England Journal of Medicine 2001; 344(2):79–86.
International Agency for Research on Cancer (2004). The INTERPHONE Study. Lyon, France: International Agency for Research on Cancer. Retrieved May 10, 2005, from
http://www.iarc.fr/ENG/Units/RCAd.html.
Christensen HC, Schuz J, Kosteljanetz M, et al. Cellular telephone use and risk of acoustic neuroma. American Journal of Epidemiology 2004; 159(3):277–283.
Lonn S, Ahlbom A, Hall P, Feychting M. Mobile phone use and the risk of acoustic neuroma. Epidemiology 2004; 15(6):653–659.
Christensen HC, Schuz J, Kosteljanetz M, et al. Cellular telephones and risk for brain tumors: A population-based, incident case-control study. Neurology 2005; 64(7): 1189–1195.
Lonn S, Ahlbom A, Hall P, et al. Long-term mobile phone use and brain tumor risk. American Journal of Epidemiology 2005; 161(6):526–535.