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As of December 2007, there was an estimated 255.4 million cell phone subscribers in the U.S. That’s 84% of the population. In fact, global mobile coverage is expected to reach 90% by 2010 says a study commissioned by the GSM Association, the global trade association for all mobile operators. With such incredible penetration, the cellular phone is fast becoming the single most important piece of personal electronics -- but at what cost and do cell phones cause brain cancer?
In May 1993, a Florida man filed a lawsuit against a cell phone manufacturer, claiming that radiation from his wife’s cell phone caused her to develop a fatal brain tumor. The case was tossed out of court for lack of evidence, but the ripple effect is still felt today and the question of "do cell phones cause cancer?" remains. The question has also become more specific: Do cell phones cause brain cancer?
What is the concern?
Obviously the main concern is the question itself: Do cell phones cause brain cancer? What, however, is behind the concern?
Cellular phones operate on radio frequencies (RF), a form of electromagnetic radiation -- waves of electric and magnetic energy that radiate at the speed of light -- that is located in the ultra-high frequency end of the electromagnetic spectrum, somewhere between FM radio waves and the waves used in microwave ovens, radars and satellites. Currently, there are no federally mandated RF standards, although the FCC does mandate a specific absorption rate (SAR) that dictates the allowable amount of RF energy that can be safely absorbed into the body. The SAR value, however, is based on the thermal effect of RFs or, in other words, how much heat your body can safely absorb rather than the cancer-causing non-thermal effects.
The amount of RF a person is exposed to from a cell phone depends on a number of factors, such as:
What does the research say?
The best way to summarize the majority of the epidemiologic data on cell phone use and brain tumors is to say that the results are mixed. And by saying that, science naysayers can immediately fall back to their comforting slogan of dissent: “Well, there’s always a study that shows one way or the other.” It’s when you combine the results of multiple studies, however, that a true trend begins to appear. Enter the meta-analysis.
A meta-analysis combines the results across many studies, which allows you to create one huge sample of test patients that can increase your ability to find a difference between specific populations of interest.
Getting closer to answering the question: Do cell phones cause brain cancer?
Three meta-analyses published on the topic of mobile phones and brain tumors have somewhat conflicting results. A meta-analysis of 12 studies by Lahkola et al. (2006) found little indication for increased risk of analog or digital phone use and brain tumors. Similarly, a meta-analysis of nine studies by Kan et al. (2008) found no overall increased risk for brain tumors with cell phone use, but a statistically significant 95% increase in the risk of brain tumors for long-term cell phone users (10 years or longer) according to five studies that recorded long-term data. Lastly, in two meta-analyses by Hardell et al. (2006 and 2008), long-term cell phone users were almost twice as likely than non-users to have developed acoustic neuromas (evaluated in three studies) and gliomas (evaluated in four studies), two types of brain tumors, on the same side of the brain (called ipsilateral cancers -- something that studies often fail to investigate).
Before conclusions are made, understand that meta-analyses are not the definitive answer when it comes to unraveling a mystery of this complexity; indeed they suffer from various methodological problems. If studies in a meta-analysis are too different, then combining the results can provide an incorrect summary. This is where large narrative reviews of studies come in handy. In 2007, the UK’s Mobile Telecommunications and Health Research (MTHR) Programme published a comprehensive report concluding that there is no evidence for increased risk of brain tumors with short-term cell phone use, but that further clarification is needed to confirm long-term use of 10 years or more. A less optimistic opinion was reached by Dr. Vini Khurana in his 2008 narrative review of studies; he claims that tumor risk from long-term cell phone use is no longer a myth. The FDA has yet to update its stance to include studies beyond 2006.
So, do cell phones cause brain cancer?
With such detailed and conflicting literature, it is difficult to draw a definitive conclusion, but as of now, consider this the bottom line:
Short-term cell phone use does not appear to be associated with brain tumors of any kind; however, there is a convincing trend toward an increased risk of ipsilateral brain tumors with long-term use of mobile cell phones and possibly cordless home phones. Despite this, the area requires further research, particularly in children who may be at higher risk than adults. A more definitive answer should be available in the next five to 10 years when larger studies with digital-only (not analog) cell phones can ensure long enough follow-up of patients.
How can I protect myself?
Though the risk of getting cancer from your cell phone seems minimal at the moment, if you are concerned, there are a number of ways you can go about to minimize your risk:
In May 1993, a Florida man filed a lawsuit against a cell phone manufacturer, claiming that radiation from his wife’s cell phone caused her to develop a fatal brain tumor. The case was tossed out of court for lack of evidence, but the ripple effect is still felt today and the question of "do cell phones cause cancer?" remains. The question has also become more specific: Do cell phones cause brain cancer?
What is the concern?
Obviously the main concern is the question itself: Do cell phones cause brain cancer? What, however, is behind the concern?
Cellular phones operate on radio frequencies (RF), a form of electromagnetic radiation -- waves of electric and magnetic energy that radiate at the speed of light -- that is located in the ultra-high frequency end of the electromagnetic spectrum, somewhere between FM radio waves and the waves used in microwave ovens, radars and satellites. Currently, there are no federally mandated RF standards, although the FCC does mandate a specific absorption rate (SAR) that dictates the allowable amount of RF energy that can be safely absorbed into the body. The SAR value, however, is based on the thermal effect of RFs or, in other words, how much heat your body can safely absorb rather than the cancer-causing non-thermal effects.
The amount of RF a person is exposed to from a cell phone depends on a number of factors, such as:
- The physical distance from the base station (the actual cell phone itself or, in the case of a cordless phone, the docking station).
- The duration and frequency of cell phone use, including the preferred side of the head.
- The type of phone (older analog models induce greater exposure than newer, digital ones).
What does the research say?
The best way to summarize the majority of the epidemiologic data on cell phone use and brain tumors is to say that the results are mixed. And by saying that, science naysayers can immediately fall back to their comforting slogan of dissent: “Well, there’s always a study that shows one way or the other.” It’s when you combine the results of multiple studies, however, that a true trend begins to appear. Enter the meta-analysis.
A meta-analysis combines the results across many studies, which allows you to create one huge sample of test patients that can increase your ability to find a difference between specific populations of interest.
Getting closer to answering the question: Do cell phones cause brain cancer?
Three meta-analyses published on the topic of mobile phones and brain tumors have somewhat conflicting results. A meta-analysis of 12 studies by Lahkola et al. (2006) found little indication for increased risk of analog or digital phone use and brain tumors. Similarly, a meta-analysis of nine studies by Kan et al. (2008) found no overall increased risk for brain tumors with cell phone use, but a statistically significant 95% increase in the risk of brain tumors for long-term cell phone users (10 years or longer) according to five studies that recorded long-term data. Lastly, in two meta-analyses by Hardell et al. (2006 and 2008), long-term cell phone users were almost twice as likely than non-users to have developed acoustic neuromas (evaluated in three studies) and gliomas (evaluated in four studies), two types of brain tumors, on the same side of the brain (called ipsilateral cancers -- something that studies often fail to investigate).
Before conclusions are made, understand that meta-analyses are not the definitive answer when it comes to unraveling a mystery of this complexity; indeed they suffer from various methodological problems. If studies in a meta-analysis are too different, then combining the results can provide an incorrect summary. This is where large narrative reviews of studies come in handy. In 2007, the UK’s Mobile Telecommunications and Health Research (MTHR) Programme published a comprehensive report concluding that there is no evidence for increased risk of brain tumors with short-term cell phone use, but that further clarification is needed to confirm long-term use of 10 years or more. A less optimistic opinion was reached by Dr. Vini Khurana in his 2008 narrative review of studies; he claims that tumor risk from long-term cell phone use is no longer a myth. The FDA has yet to update its stance to include studies beyond 2006.
So, do cell phones cause brain cancer?
With such detailed and conflicting literature, it is difficult to draw a definitive conclusion, but as of now, consider this the bottom line:
Short-term cell phone use does not appear to be associated with brain tumors of any kind; however, there is a convincing trend toward an increased risk of ipsilateral brain tumors with long-term use of mobile cell phones and possibly cordless home phones. Despite this, the area requires further research, particularly in children who may be at higher risk than adults. A more definitive answer should be available in the next five to 10 years when larger studies with digital-only (not analog) cell phones can ensure long enough follow-up of patients.
How can I protect myself?
Though the risk of getting cancer from your cell phone seems minimal at the moment, if you are concerned, there are a number of ways you can go about to minimize your risk:
- Use a landline phone.
- Limit your cell phone use.
- Do not let small children use cellular or cordless phones.
- Use the speakerphone or “in-vehicle hands-free” mode to increase the distance from the antenna to your head; Bluetooth devices and unshielded headsets should likely be avoided