Are Cell Phone Towers Dangerous? Are Cell Phones Dangerous?
This is a common question I get from friends. Recently, I was talking to a Verizon expert who noted that he and colleagues have a general rule to not carry cell phone in pants pocket because of the risk of cancer: particularly testicular cancer
So far, no proof of cell towers nor of cell phones causing birth defects but there are reports as you likely know of cell phones associated with cancers. Below are some papers noting a possible link. However, there are no randomized, controlled, double blinded studies on cell phones or cell phone towers and the risk for future cancer.
Time will tell the truth. For now, it is likely best to keep your cell away from your body as much as possible.
While I would likely not buy a house right under a cell phone tower, I cannot say there is documented proof to say cell phone towers are a serious health concern.
Sandra Lora Cremers, MD, FACS
1. From a publication from PUBMED:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2569116/
Environ Health Perspect. 2008 Oct; 116(10): A422.
PMCID: PMC2569116
Environews
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Cancer: Strong Signal for Cell Phone Effects
With 3 billion cell phone users worldwide and more than 260 million in the United States alone—among them 46% of U.S. children aged 8–12, according to Nielsen Mobile figures released 10 September 2008—human exposure to low-energy radiation in the 800- to 2,000-megahertz range is at an all-time high. The most recent attempt to systematically review the epidemiologic evidence for increased risk of brain tumors related to cell phone use indicates that repercussions from this global experiment are coming to light. In a meta-analysis published in the May 2008 issue of the International Journal of Oncology, Swedish researchers found significant associations between long-term cell phone use and brain tumor risk.
“We found that cell phone use is linked to gliomas [malignant brain tumors] and acoustic neuromas [benign tumors of the brain’s auditory nerve] and are showing up after only ten years,” says lead author Lennart Hardell, an oncologist and cancer epidemiologist at University Hospital in Örebro, Sweden. Specifically, for studies that included at least 10 years of exposure, there was a doubling in the risk of gliomas for ipsilateral (same-side) but not contralateral (opposite-side) exposures to the head (as reflected by which hand the subject typically used to hold his/her cell phone). A 2.4-fold increase in risk was seen for acoustic neuromas due to ipsilateral exposures, whereas no increased risk occurred for meningiomas (tumors that occur in the membranes covering the brain and spinal cord).
“Clearly we need more studies of long-term cell phone usage to better assess the cancer risks,” says coauthor Michael Carlberg. Cell phones have been in mainstream usage for only a decade or so, and yet radiation-induced brain tumors normally take about 10–15 years to develop, according to the American Cancer Society.
Hardell’s research team was itself the source of several studies included in the meta-analysis. In the October 2006 issue of the World Journal of Surgical Oncology, the investigators reported a 70% increased risk of grade III–IV astrocytomas (highly aggressive brain tumors) for analog cell phone users. This same study found a nearly 4-fold increase in risk for acoustic neuromas after 15 years of exposure to analog cell phones. Notably, there was no increased risk for testicular cancer, B-cell lymphoma, or salivary gland tumors, suggesting that the findings were not due to observational or recall bias, as such bias should have existed for all tumor types.
To address whether their earlier studies may have skewed the conclusions of their 2008 meta-analysis, the team omitted their own studies from the analysis and still found significantly increased risk for gliomas and nonsignificantly increased risk for acoustic neuromas (50% and 210% increases, respectively) for ipsilateral exposures. “We are now seeing a consistent pattern of increased risk for glioma and acoustic neuroma,” says coauthor Kjell Hansson Mild, a radiation physicist at Umeå University, Sweden. “Not only our own studies are showing this but also all other studies that have included at least ten years as a latency period.”
Emerging evidence suggests that children may be more vulnerable to the potential carcinogenic effects of cell phones and other microwave-emitting technologies. “Concerns about children’s potential vulnerability to RF [radiofrequency] fields have been raised because of the potentially greater susceptibility of their developing nervous systems,” says Leeka Kheifets, an epidemiology professor at the University of California, Los Angeles, and former director of the Electric Power Research Institute EMF research program. “In addition, their brain tissue is more conductive, RF penetration is greater relative to head size, and they will have a longer lifetime of exposure [although the degree of risk for any carcinogen will be primarily determined by the exact timing and magnitude of exposure].”
The importance of a thinner skull and differing dielectric properties is confirmed by a study in the 7 June 2008 issue of Physics in Medicine and Biology showing that a child’s brain absorbs up to twice as much RF as an adult brain. Children today will experience a longer period of exposure because they start using cell phones at an earlier age, according to Hardell; this might be important, because cumulative dose seems to have a strong influence on increased risk of brain tumors. Kheifets adds, however, that “data are lacking on effects of exposures on brain tumors in children . . . [and] other health effects need to be looked at as well.”
The wireless industry takes a cautious view of the research. “The weight of the scientific evidence and the conclusions of a large number of expert scientific reviews show that wireless phones do not pose a health risk,” says Joseph Farren, assistant vice president for public affairs with CTIA–The Wireless Association. “The industry supports continued research as technology continues to evolve, but wishes to stress the fact that there is a consensus among leading health organizations regarding published scientific research showing no reason for concern.”
Hardell concedes it is too soon to determine a safe limit for cell phone use. “Can we say that a ten-minute call is equal to ten one-minute calls?” he asks. “Until we answer such questions, we cannot establish a new limit or even state which parameters or units help define that limit. Nonetheless, since we do see an increased risk of brain tumors, it is necessary to apply the precautionary principle in this situation, especially for long-range exposures that are likely to affect children in particular.” In practice, this might involve limiting children’s use of cell phones and using speaker phones to minimize direct exposure to the head.
Effect of cell phone-like electromagnetic radiation on primary human thyroid cells.
Abstract
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Cellular Phone Towers
Cellular (cell) phones first became widely available in the United States in the 1990s, but since then their use has increased dramatically. The widespread use of cell phones has led to cell phone towers being placed in many communities. These towers, also called base stations, have electronic equipment and antennas that receive and transmit radiofrequency (RF) signals.
How do cellular phone towers work?
Cell phone base stations may be free-standing towers or mounted on existing structures, such as trees, water tanks, or tall buildings. The antennas need to be high enough to adequately cover the area. Base stations are usually from 50-200 feet high.
Cell phones communicate with nearby cell towers mainly through radiofrequency (RF) waves, a form of energy in the electromagnetic spectrum between FM radio waves and microwaves. Like FM radio waves, microwaves, visible light, and heat, they are forms of non-ionizing radiation. This means they cannot cause cancer by directly damaging DNA. RF waves are different from stronger types of radiation such as x-rays, gamma rays, and ultraviolet (UV) light, which can break the chemical bonds in DNA.
At very high levels, RF waves can heat up body tissues. (This is the basis for how microwave ovens work.) But the levels of energy used by cell phones and towers are much lower.
When a person makes a cell phone call, a signal is sent from the phone’s antenna to the nearest base station antenna. The base station responds to this signal by assigning it an available radiofrequency channel. RF waves transfer the voice information to the base station. The voice signals are then sent to a switching center, which transfers the call to its destination. Voice signals are then relayed back and forth during the call.
How are people exposed to the energy from cellular phone towers?
As people use cell phones to make calls, signals are transmitted back and forth to the base station. The RF waves produced at the base station are given off into the environment, where people can be exposed to them.
The energy from a cellular phone tower antenna, like that of other telecommunication antennas, is directed toward the horizon (parallel to the ground), with some downward scatter. Base station antennas use higher power levels than other types of land-mobile antennas, but much lower levels than those from radio and television broadcast stations. The amount of energy decreases rapidly as the distance from the antenna increases. As a result, the level of exposure to radio waves at ground level is very low compared to the level close to the antenna.
Public exposure to radio waves from cell phone tower antennas is slight for several reasons. The power levels are relatively low, the antennas are mounted high above ground level, and the signals are transmitted intermittently, rather than constantly.
At ground level near typical cellular base stations, the amount of RF energy is thousands of times less than the limits for safe exposure set by the US Federal Communication Commission (FCC) and other regulatory authorities. It is very unlikely that a person could be exposed to RF levels in excess of these limits just by being near a cell phone tower.
When a cellular antenna is mounted on a roof, it is possible that a person on the roof could be exposed to RF levels greater than those typically encountered on the ground. But even then, exposure levels approaching or exceeding the FCC safety guidelines are only likely to be found very close to and directly in front of the antennas. If this is the case, access to these areas should be limited.
The level of RF energy inside buildings where a base station is mounted is typically much lower than the level outside, depending on the construction materials of the building. Wood or cement block reduces the exposure level of RF radiation by a factor of about 10. The energy level behind an antenna is hundreds to thousands of times lower than in front. Therefore, if an antenna is mounted on the side of a building, the exposure level in the room directly behind the wall is typically well below the recommended exposure limits.
Do cellular phone towers cause cancer?
Some people have expressed concern that living, working, or going to school near a cell phone tower might increase the risk of cancer or other health problems. At this time, there is very little evidence to support this idea. In theory, there are some important points that would argue against cellular phone towers being able to cause cancer.
First, the energy level of radiofrequency (RF) waves is relatively low, especially when compared with the types of radiation that are known to increase cancer risk, such as gamma rays, x-rays, and ultraviolet (UV) light. The energy of RF waves given off by cell phone towers is not enough to break chemical bonds in DNA molecules, which is how these stronger forms of radiation may lead to cancer.
A second issue has to do with wavelength. RF waves have long wavelengths, which can only be concentrated to about an inch or two in size. This makes it unlikely that the energy from RF waves could be concentrated enough to affect individual cells in the body.
Third, even if RF waves were somehow able to affect cells in the body at higher doses, the level of RF waves present at ground level is very low – well below the recommended limits. Levels of energy from RF waves near cell phone towers are not significantly different from the background levels of RF radiation in urban areas from other sources, such as radio and television broadcast stations.
For these reasons, most scientists agree that cell phone antennas or towers are unlikely to cause cancer.
Studies in people
Very few human studies have focused specifically on cellular phone towers and cancer risk.
In one large study, British researchers compared a group of more than 1,000 families of young children with cancer against a similar group of families of children without cancer. They found no link between a mother’s exposure to the towers during pregnancy (based on the distance from the home to the nearest tower and on the amount of energy given off by nearby towers) and the risk of early childhood cancer.
In another study, researchers compared a group of more than 2,600 children with cancer to a group of similar children without cancer. They found that those who lived in a town that could have exposed them to higher than average RF radiation from cellular phone towers in the previous 5 years had a slightly higher risk of cancer, although not of any certain type of cancer (like leukemia or brain tumors). This study estimated the children’s possible exposure based on the number of towers in their town and how strong the signals were from the towers. It did not look at actual exposure of any individual child based on how far their home or school was from a tower. This limitation reduces confidence in the results of the study.
One study looked for signs of DNA and cell damage in blood cells as a possible indicator of cancer-causing potential. They found that the damage was no worse in people who lived near a cell phone tower as compared with those didn’t.
The amount of exposure from living near a cell phone tower is typically many times lower than the exposure from using a cell phone. About 30 studies have looked at possible links between cell phone use and tumors in people. Most studies to date have not found a link between cell phone use and the development of tumors, although these studies have had some important limitations. This is an area of active research. For more information, see the document, Cellular Phones.
Studies done in the lab
Laboratory studies have looked at whether the types of RF waves used in cell phone communication can cause DNA damage. Most of these studies have supported the idea that the RF waves given off by cell phones and towers don’t have enough energy to damage DNA directly.
Some scientists have reported that the RF waves may produce other effects in human cells (in lab dishes) that might possibly help tumors grow. However, these studies have not been verified, and these effects weren’t seen in a study that looked at the blood cells from people living near a cellular phone tower.
Several studies in rats and mice have looked at whether RF energy might promote the development of tumors caused by other known carcinogens (cancer-causing agents). These studies did not find evidence of tumor promotion. Research in this area continues.
What expert agencies say
About cell phone towers
The 3 expert agencies that usually classify cancer-causing exposures (carcinogens) – the International Agency for Research on Cancer (IARC), the National Toxicology Program (NTP), and the US Environmental Protection Agency (EPA) – have not classified cell phone towers as to their cancer-causing potential.
The US Federal Communications Commission (FCC) has said this about cell phone towers near homes or schools:
“Radiofrequency emissions from antennas used for cellular and PCS [personal communications service] transmissions result in exposure levels on the ground that are typically thousands of times below safety limits. These safety limits were adopted by the FCC based on the recommendations of expert organizations and endorsed by agencies of the Federal Government responsible for health and safety. Therefore, there is no reason to believe that such towers could constitute a potential health hazard to nearby residents or students.”
About RF radiation
Some of the agencies that classify cancer-causing exposures have, however, made statements about radiofrequency radiation.
The International Agency for Research on Cancer (IARC) has classified RF fields as “possibly carcinogenic to humans,” based on limited evidence of a possible increase in risk for brain tumors among cell phone users, and inadequate evidence for other types of cancer. (For more information on the IARC classification system, see our document, Known and Probable Human Carcinogens.) IARC also noted that exposure to the brain from RF fields from cell phone base stations (mounted on roofs or towers) is less than 1/100th the exposure to the brain from mobile devices such as cell phones.
The Environmental Protection Agency (EPA) states:
“At very high levels, RF energy is dangerous. It can heat the body’s tissues rapidly. However, such high levels are found only near certain equipment, such as powerful long-distance transmitters. Cellphones and wireless networks produce RF, but not at levels that cause significant heating. In addition, RF energy decreases quickly over distance. At ground level, exposure to RF from sources like cellphone towers is usually very low.
Some people are concerned about potential health effects, especially on the developing brains and bodies of children. Some studies suggest that heavy long-term use of cellphones could have health effects. Other studies don’t find any health effects from cellphone use. Long-term studies on animals exposed to the RF found in wireless networks (Wi-Fi) have, so far, found no health effects. Scientists continue to study the effects of long-term exposure to low levels of RF.”
Can I limit my exposure?
Cell phone towers are not known to cause any health effects. But if you are concerned about possible exposure from a cell phone tower near your home or office, you can ask a government agency or private firm to measure the RF field strength near the tower (where a person could be exposed) to ensure that it is within the acceptable range.
What should I do if I’ve been exposed to cellular phone towers?
There is no test to measure whether you have been exposed to RF radiation from cellular phone towers. But as noted above, most researchers and regulatory authorities do not believe that cell phone towers pose health risks under ordinary conditions. If you have additional health concerns, you might want to talk with your doctor.
Additional resources
More information from your American Cancer Society
The following related information may also be helpful to you. These materials may be viewed on our Web site or ordered from our toll-free number, at 1-800-227-2345.
National organizations and Web sites*
In addition to the American Cancer Society, other sources of information and support include:
Environmental Protection Agency
Home page: www.epa.gov
Understanding radiation: www.epa.gov/
Home page: www.epa.gov
Understanding radiation: www.epa.gov/
Federal Communications Commission
RF Safety Program, Office of Engineering and Technology
Web site: www.fcc.gov/oet/rfsafety
RF Safety Program, Office of Engineering and Technology
Web site: www.fcc.gov/oet/rfsafety
Food and Drug Administration
Home page: www.fda.gov
Radiation-emitting products: Cell phones: www.fda.gov/Radiation-
Home page: www.fda.gov
Radiation-emitting products: Cell phones: www.fda.gov/Radiation-
National Cancer Institute
Toll-free number: 1-800-422-6237 (1-800-4-CANCER)
Home page: www.cancer.gov
Cellular telephone use and cancer risk: www.cancer.gov/
Toll-free number: 1-800-422-6237 (1-800-4-CANCER)
Home page: www.cancer.gov
Cellular telephone use and cancer risk: www.cancer.gov/
National Institute of Environmental Health Sciences
Home page: www.niehs.nih.gov
Electric and magnetic fields: www.niehs.nih.gov/
Home page: www.niehs.nih.gov
Electric and magnetic fields: www.niehs.nih.gov/
World Health Organization
Electromagnetic fields and public health: base stations and wireless technologies
Web site: www.who.int/mediacentre/
Electromagnetic fields and public health: base stations and wireless technologies
Web site: www.who.int/mediacentre/
* Inclusion on this list does not imply endorsement by the American Cancer Society
No matter who you are, we can help. Contact us anytime, day or night, for information and support. Call us at 1-800-227-2345 or visit www.cancer.org.
References
ANSI-C95.1, 1982, American National Standards Institute. American national standard safety levels with respect to human exposure to radiofrequency electromagnetic fields, 300 kHz to 100 Ghz. New York: IEEE.
Baan R, Grosse Y, Lauby-Secretan B, El Ghissassi F, Bouvard V, Benbrahim-Tallaa L, Guha N, Islami F, Galichet L, Straif K; WHO International Agency for Research on Cancer Monograph Working Group. Carcinogenicity of radiofrequency electromagnetic fields. Lancet Oncol. 2011 Jul;12(7):624-626.
Elliott P, Toledano MB, Bennett J, et al. Mobile phone base stations and early childhood cancers: case-control study.BMJ. 2010;340:c3077. [Epub]
Federal Communications Commission, Office of Engineering and Technology. Radio Frequency Safety. 6/25/2012. Accessed at www.fcc.gov/oet/rfsafety/rf-
IEEE-C95.1, 1991, Institute of Electrical and Electronics Engineers, Inc. Safety levels with respect to human exposure to radio frequency electromagnetic fields, 3 kHz to 300 Ghz. Piscataway, NJ: IEEE.
IEEE: Institute of Electrical and Electronics Engineers, Inc. Human exposure to RF emissions from cellular radio base station antennas; Washington, DC: 1992.
ICNIRP: International Commission on Non-Ionizing Radiation Protection. Health Issues related to the use of hand-held radiotelephones and base transmitters. Health Physics. 1996;70:587-593.
IRPA, 1988, International Radiation Protection Association. Guidelines on limits of exposure to radio frequency electromagnetic fields. IEEE United States Activities, COMAR, Washington, DC.
Li CY, Liu CC, Chang YH, Chou LP, Ko MC. A population-based case-control study of radiofrequency exposure in relation to childhood neoplasm. Sci Total Environ. 2012 Oct 1;435-436:472-478.
NCRP, 1986, National Council on Radiation Protection. Biological effects and exposure criteria for radiofrequency electromagnetic fields. Report 86, (Bethesda, MD: National Council on Radiation Protection and Measurements) pp. 1-382.
Repacholi M, van Deventer E, Ravazzani P, eds. Base stations and wireless networks: exposures and health consequences. World Health Organization. Accessed at http://whqlibdoc.who.int/
Röösli M, Frei P, Mohler E, Hug K. Systematic review on the health effects of exposure to radiofrequency electromagnetic fields from mobile phone base stations. Bull World Health Organ. 2010 Dec 1;88(12):887-896F.
Rothman KJ, Chung-Kwang C, Morgan R, et al. Assessment of cellular telephone and other radio frequency exposure for epidemiologic research. Epidemiology. 1996;7:291-298.
United States Environmental Protection Agency. RadTown USA: Non-ionizing radiation from wireless technology. Accessed at www.epa.gov/radtown/wireless-
Valberg PA. Radio frequency radiation (RFR): the nature of exposure and carcinogenic potential. Cancer Causes Control. 1997;8:323-332.
Wolf R, Wolf D. Increased incidence of cancer near a cell-phone transmitter station. Int J Cancer Prevention2004;1:123-128.
Yildirim MS, Yildirim A, Zamani AG, Okudan N. Effect of mobile phone station on micronucleus frequency and chromosomal aberrations in human blood cells. Genet Couns. 2010;21(2):243-51.
Last Medical Review: 12/02/2014
Last Revised: 12/02/2014
Last Revised: 12/02/2014
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Dangers of cell phone usage revealed in radiation level studies |
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Mon, 01 Jul 2013 16:54:00
Cell phones have become ubiquitous in today’s society. It’s almost as if you don’t have one, then you’re not living in the 21st century.
The great thing about cell phones is that they enable us to stay connected with other people nearly all the time. Cell phones happen to be handy in an emergency. They also come in handy when we are traveling. Today, the traditional landline has begun to go the way of the dinosaur, as many people have now canceled their landlines and rely only on cell phones. “All cell phones emit radiation by definition because they talk to or connect to a local tower,” said Erik Peper, Ph.D., professor of holistic health at San Francisco State University. As long as a cell phone is being used for talking, texting, streaming data, or audiovisual data, it is communicating with the tower and therefore emitting radiation. A radiation level of 0.2 watts per kilogram up to 1.6 watts per kilogram is considered safe by the Federal Communications Commission — FCC. If a cell phone has a radiation level above 1.6 watts per kilogram, it is illegal to sell it. Radiation is a concern especially for groups of people who are constantly on their cell phones. A 2012 survey conducted by Peper and others revealed that the average college student uses their cell phone and tablet/iPad for at least 118 minutes per day, including 40 minutes right before they go to sleep. This equates to 19.7 days per year of talking and texting on their smartphones, “and high school students use their cell phones even more,” Peper pointed out. The World Health Organization has classified mobile phones — and any wireless devices that use microwaves to communicate — as a group 2b risk — which means that they are “possibly carcinogenic to humans.” Mobile phones are in the same category as automotive fuel exhaust, according to Peper. It has been reported in research studies that adults who have used mobile phones for at least 10 years experience an increase in brain cancer, salivary gland cancer, and even rare eye cancers on the side of the head where the cell phone was predominantly held, according to Peper. Recently, women who habitually stored their cell phone in their bra have been diagnosed with a rare breast cancer located beneath the area of the breast where they stored their cell phone, Peper additionally noted. Further, some men diagnosed with testicular cancer had the cancer occur in the testicle that was closest to the pants pocket where they kept their cell phone. Stan Glantz, professor of medicine at the University of California at San Francisco — UCSF — and director of the Center for Tobacco Research and Education, compared the cell phone situation right now to the cigarette situation in the 1950s. “There was enough evidence to be concerned [about cigarettes in the 1950s], but the details were not really nailed,” Glantz said. “Cell phone companies have learned from cigarette companies how to contest science, and they’re doing it.” Joel Moskowitz, director of the Center for Family and Community Health at the University of California at Berkeley, has launched a social media campaign to raise awareness about the risk of cell phones, encourage safe cell phone use and promote better regulation and more research on the subject. “We don’t want to engage in scare tactics but safe cell phone use,” Moskowitz said. “We’re not telling anybody to give up their cell phone or ditch their cell phone carrier.” What are the best ways to reduce radiation from your cell phone? – Do not put it against your body. Put it in your purse, your backpack, or your case. Ellie Marks — who founded the California Brain Tumor Association with her son Zack in 2009 — knows first-hand about the effects of cell phone radiation. Her husband, Alan, a realtor, developed a brain tumor that was attributed to his cell phone use. Marks said that he still uses a cell phone, but now he never holds it next to his body. “We’ve learned the hard way how to eliminate risks without giving up technology,” Marks stated. “It has just devastated our family.” In 2008, just a few months after her husband’s surgery, Marks testified to the U.S. Congress in a hearing on cell phones and health risks. She said that her husband’s story has been told on such shows as Dr. Oz, The View, Larry King Live and Sanjay Gupta. Marks was extremely disappointed in May when the San Francisco Board of Supervisors approved a plan to repeal the Cell Phone Right to Know ordinance. The ordinance — approved by the Board in 2010 and amended in 2011 — sought to require cell phone retailers to provide customer with information about alleged possible dangers associated with radiation from the devices and ways that users could reduce their exposure. “Cell phone companies have won,” Marks said. “It was very sad. Many of us have worked on this for years. It was such a sad day. It felt like the politics in San Francisco has changed considerably, and no one was standing up for public health. It just didn’t seem like the Supervisors had the backbone that they used to have.” Inquiries may be sent to epeper@sfsu.edu. More information can also be found at http://www.sfsu.edu/~ihhs/ |
