Health Risks Related to Cell Phone Usage


 * For a similar entry concerning cell phone usage and health, see Mobile phone radiation and health.

Recent health studies have purported to show a connection between the use of wireless mobile telephony and health issues. Research has focused on the electromagnetic radiation emitted by cellular phones and its possible relationship to cancers, including brain tumours such as malignant glioma, and nerve tumours such as vestibular schwannoma. However, there is much controversy over whether or not such research has enough breadth - that is to say, whether such studies can effectively measure the impact over time - to make substantial claims as to the dangers. In the same way, there are varying views as to the course of action that must be taken to ensure the safety of cell phone users. The goal of our group project is to explore the depth of certainty these studies confute, and as a result, what sort of action should be taken in regards to cell phone safety.

Radio Frequency


Cell phones essentially work along the same processes as radios. Radios transmit signals of a particular frequency channel in order to move information - be it music, conversations, or pictures, etc. Fluctuations of electric and magnetic fields move in wave-like patterns, known as electromagnetic radiation. The energy contained within the wave affects the length and frequency of the wave. Frequency is measured in Hertz, which the number of cycles per second. Radiofrequency radiation is a form of electromagnetic radiation operating within the frequencies of 900 to 1800 MHz, however, cell phones are capable of utilizing and commonly surpass frequencies of 1800MHz. This frequency of electromagnetic radiation is also particular to television and radio broadcasts. Traditional radio technologies such as walkie-talkies and CB radios relate to one another on the same frequency. Walkie-talkies are able to act on only one channel, whereas CB radios can be utilized on 40 seperate channels.[14][16]

Cell Phone Transmission
Radio frequency radiation is the means of the mobile phone to connect with the base station, even while the phone is not in use. In contrast to older radio oriented technologies, the range of frequency in which cell phones communicate allows them to transmit on over 1,664 channels.[15]

In order to keep a continuous connection between the transmitter in a mobile phone and a base station, each base station is networked with its peers, and each network of base stations is hooked up to a single control unit. This is known as a cellular network. Due to the commonality of frequencies, some mobile wireless carriers such as Rogers Wireless make use of SIM cards to create unique ID's to communicate between the mobile phone and the base station.[22]

The source of the radio frequency radiation can be tracked to a pair of transmitters and receivers that send out and receive sine waves through the antenna. The power of the mobile phone transmitter generally falls into the range of 1 watt which qualifies as an ELF(extremely low frequency), however, some of the more complex mobile phones require more power. The closer a transmitter is to a base station, the less power it uses, and the further away the transmitter is, the more power it uses. The extra power is required to increase the signal to noise ratio of the frequency to make sure that there is enough of the original signal to be received and processed. The transmitter also has a power amplifier that will autoregulate the power usage depending on the distance between itself and a base station.

Three common types of radio frequencies found in mobile technology are GCM, DCS, and PCS frequencies. The main differences between these are that GCM operates at 800MHz, DCS operates at 1800MHz, PCS operates at 1900MHz, and bands may be more common in specific regions(ex: PCS can only be found in North America). Similar to the auto regulation of power, the transmitter will autodetect and regulate which frequency to be used.[19][21]



Some common cellular networks that can be found in North America are EDGE(Enhanced Data Rates for GSM Evolution), 3G, GPRS(General Packet Radio Service), EVDO(Evolution Data Optimized), and GSM (Global System for Mobile communication) which happens to be the most common type. These are the protocols through which frequencies are actually transmitted and each type has its own bandwidth (rate of data transfer) and method of transmitting frequencies.

Regulations
Radiofrequency radiation is non-ionizing, meaning it does not remove electrons from affected atoms, but only incites electrons to a higher energy state. Since it does not result in negative or positively charged ions, it does not directly alter genetic material.[1] Nonetheless, there is potential for negative reprocussions of high concentrations of radiofrequency radiation in the body. The radiation penetrates approximately two inches into an adult brain and has been shown to penetrate past the center of a child’s brain.[2] Site-specific absorption rate (SAR) is a method of measuring the quantity of radiofrequency absorbed by the body. The measurement is a power-to-weight ratio that expresses the relationship between electrical output and produced heat. Higher concentrations of radiofrequency radiation creates thermal energy; regulations are in place to protect the public from the potential damaging effects of thermal radiation. FCC certification and certification within Canada requires the SAR to be below 1.6 W/kg[13]. The regulations vary country to country, but the allowable levels of frequency are gauged to studies conducted by the World Health Organization, the Institute of Electrical and Electronics Engineers, and the International Commission on Non-Ionizing Radiation Protection.[1]

Effects of Radiofrequency Radiation
The ambiguity and uncertainty surrounding this issue is largely a result from the uncertainty of radiofrequency radiation of human and mammalian cells.[1] Non-ionizing radiation assumedly does not have sufficient energy to directly cause DNA damage.[3]  Yet cell death and degeneration has been linked through a number of other theories of frequency affectation.

Thermal Effects
Exposure regulations and standards placed forth by health committees are based on the proportion of heat in regions of the head. The average is taken over 10g volumes of tissue region in 6 minute intervals. However, there can occur momentary higher intensities within a 10g volume, resulting in dangerous thermal effects.[4] Thermal effects of electromagnetic radiation include DNA damaging and gene mutations.[5]

Cellular Stress
Heat shock proteins act as signals that a cell is under physiological stress, be it a result of heat shock, oxygen deficiency, and toxic encounters. Radiofrequency fields activate specific transcription factor binding that stimulate cell proliferation and induce stress proteins. Not only is this an indication that such frequency emissions are harmful for cells encountered, but the stress induced persists for excessive time periods, resulting in a diminished effective protection of heat shock proteins.[6]

Genotoxicity
Cells that have genotoxic attributes are considered cancerous in that they are involved in the altercation of somatic cells. Although it is not the case that radiofrequency exposure induces genotoxic action to take place, genotoxic events are amplified. Radiofrequency that has a SAR under 2 W/kg does not thermally impact human cells. However, there is an observable microthermal mechanism that enhances genotoxic effects. Thus, radiofrequency causes structural anomalies within chromosomes, and single and double strand breaks within DNA.[7]

Genetic Affectations
Non-ionic radiation does not contain enough energy to directly damage DNA[1], since it is not incited by thermal energy or electrical current. However, genes regulating cell growth and function have been found to express different when in contact with radiofrequency. The altered expression of genes involved in cytoskeleton, transduction, and metabolistic cellular functions can result in DNA activation (as in stress response) and DNA damage. Brain cancers have also been linked to non-thermal DNA affectations and gene induction.[7].

Short Term Conditions
People who are chronically exposed to low-level frequency emissions report symptoms such as problems in insomnia, as well as other symptoms that include fatigue, headache, dizziness, grogginess, lack of concentration, memory problems, tinnitus, problems with balance and orientation, and difficulty in multi-tasking. Cognitive impairment including loss of mental concentration, distraction, speeded mental function but lowered accuracy, impaired judgment, delayed reaction time, spatial disorientation, slower motor skills and reduced learning ability in children and adults have been reported. [3]

Malignant Brain Tumours
The most substantial evidence for the harmful effects of radiofrequency exposure is the increased risk of malignant glioma – that is, cancers within the brain and spine – for persons who have utilized mobile phones for over ten years. Also, the risk is associated with ipsilateral use of phones, indicating a direct connection to the frequency exposure. The risk of malignant glioma increased by 50% with frequent use of mobile phones on one side of the head.[8] Other increased ipsilateral indicators include vestibular shwannoma (the risk for which increased by 210%), a benign intracranial tumour of the auditory nerve, and parotid gland tumours, which appear in the salivary gland of the cheek.[3]

The diagnosis of malignant glioma requires to be done. In most cases, an abnormality occurs and a referral to a neurosurgeon is recommended. Even though the tumors can be seen on a CT or MRI, often surgery is needed to correctly diagnose the tumor because it has very similar appearance to many other tumors. Malignant glioma often reoccurs, and in most cases, it re-occurs within months of a surgery being done. This is because often not all cells of the tumor can be removed. This poses a problem in the long term treatment of the condition.

Children's Susceptibility
A number of factors, including a thinner skull, thinner pinna in the ear, and a great susceptibility to environmental affects during developing years (due to an increased activity and division of cells), children’s brains absorb twice as much radiofrequency radiation than the average adult brain. Thus, the risk for children developing malignant brain tumours is 5.2 times that of an adult. There is also the possibility that such radiation will impact children’s ability for normal nervous system, behavioural, and cognitive development. Reactive oxygen radicals incited by radiofrequencies have resulted in brain function changes within children, including memory loss, slowed learning, decreased motor function, and performance impairment. These have also been accompanied with increased headaches, fatigue, and sleep disorders.[3] The concern for safety of children has escalated in recent years over the increased number of young people utilizing cell phones. In the US, 17 million teens (or 76%) are cell phone users.[11]

Criticisms
There have been numerous studies within the past few decades as to the possible effects of cell phones on persons. The causal connection to cancer seems to be uncertain, as there are many possible ways frequency can act on living organisms. Both the American Cancer Society and the Food and Drug Administration have stated that there is no consistent association between cell phones and brain tumours.[9] Further, many studies have had contradicting conclusions. The Swedish National Institute for Working Life claimed an increased risk by a factor of 2.4, whereas similar studies by British and Dutch researches have established no connection.

It has also been shown that many of the studies have operated on a tendency towards a [Wikipedia:Publication bias|publication bias]. The overall data of a meta-analysis of many studies has shown the difference between radiofrequency exposure and unexposed controls as well as the effect size or standardized mean difference was small with very few exceptions. Further, chromosomal anomalies were within the spontaneous levels reported in historical databases. However, the quality of such publications has increased from 2% in 1995-1999 to 48% from 2000-2005.[10] An issue presented is that most studies are the result of short-term usage of cell phones, generally within a period of three years. Evidently, there needs to be a deeper investigation into the long-term effects of radiofrequency radiation before scientifically certain conclusions can be drawn.[9]

LG 150 Recall
LG Electronics was notified that one of their cellphones did not meet a certification known as Radio Standards Specification 102 (RSS 102). The RSS 102 sets out to test and control the use of radio frequencies used within a certain vicinity of people. The only phone by LG that was affected was the LG 150. However, it was not a mandatory recall and only the people who wanted to have the phone replaced were required to.



Appropriate Courses of Action
Evidently the true facts behind cell phones and the possible health implications are not fully known. However, since a connection has been drawn to malignant brain tumours, it is clear that action must be taken to supercede the possible health and societal costs that impend the future. [12]

Firstly, it is the responsibility of wireless technology manufacturers to research new and dependably safe technologies. Not only is this in the interest of the health of the population, who may be adversely affected by the long term use of the current technologies, but also in the interest of investors and shareholders. The possibility of a definitive publication being posed as to the harmful effects of cell phones would be detrimental to a corporation involved in mobile telephony.

Furthermore, research needs to continue to be implemented to delve further into the causal connection between cell phones and health. There needs to be a greater understanding of the impact of radiofrequency on human cells, the long term effects of radiofrequency radiation (over a period greater than 10 years), the role cell phones play in the extent of radiofrequency effects, and what regulations must thereby be placed on cell phone technologies. This will also provide revelation into the concern for children’s safety, as we have a greater understanding of how high the levels of developmental risk is for children

Finally, education and preventative strategies must be made available to the public. Although the risk is currently small, many things can be done to limit the potential risk. Hands-free devices provide an alternative to direct contact with radiofrequency exposure. Although Bluetooth devices act along a microwave frequency, they are of considerably lower risk than mobile phones. Speakerphone is also a viable alternative. It is recommended that all persons attempt to keep conversation short when operating mobile technology, and children avoid using cell phones due to their increased susceptibility to the radiofrequency radiation.

Group Information
Tutorial 20 - Group 3

Members
Kevin Persaud

Cara Schulz

Brigitte Sullivan

Breanne Thompson

Dustin Thul

Notes & References

 * 1) Kohli, D., A. Sachdev, and H. Vats. "Cell phones and tumor: Still in no man's land.(Review Article)(Report). ." Indian Journal of Cancer.  46.1 (Jan-March 2009): 5.
 * 2) Pease, C. (2009, January). Do Cell Phones Cause Cancer?. Environmental Forum, 26(1), 18-18. Retrieved March 23, 2009, from Environment Complete database.
 * 3) Sage, C., & Carpenter, D. O. Public health implications of wireless technologies. Pathophysiology, In Press, Corrected Proof.
 * 4) Blackman, C. Cell phone radiation: Evidence from ELF and RF studies supporting more inclusive risk identification and assessment. Pathophysiology, In Press, Corrected Proof.
 * 5) Vijayalaxmi and Prihoda, T. J. Genetic Damage in Mammalian Somatic Cells Exposed to Radiofrequency Radiation: A Meta-analysis of Data from 63 Publications (1990–2005). Radiat. Res. 169, 561–574 (2008).
 * 6) Blank, M., & Goodman, R. Electromagnetic fields stress living cells. Pathophysiology, In Press, Corrected Proof.
 * 7) Ruediger, H. W. Genotoxic effects of radiofrequency electromagnetic fields. Pathophysiology, In Press, Corrected Proof.
 * 8) Khurana, V., Moulder, J., & Orton, C. (2008, December). There is currently enough evidence and technology available to warrant taking immediate steps to reduce exposure of consumers to cell-phone-related electromagnetic radiation. Medical Physics, 35(12), 5203-5206. Retrieved March 23, 2009, doi:10.1118/1.3013548
 * 9) Kharif, Olga. "Cell Phones and Cancer: More Research Needed; A large-scale study of the long-term effects of cell-phone use needs to be carried out, medical professionals said at a congressional hearing.(TECHNOLOGY). ." Business Week Online.  (Sept 26, 2008): NA. CPI.Q (Canadian Periodicals). Gale.
 * 10) Mead, M. (2008, October). Strong Signal for Cell Phone Effects. Environmental Health Perspectives, 116(10), A422-A422. Retrieved March 23, 2009, from Environment Complete database.
 * 11) Gauging cell phones' possible risk. (2009, January). Consumer Reports, Retrieved March 23, 2009, from Business Source Complete database.
 * 12) Hardell, L., Carlberg, M., & Hansson Mild, K. Epidemiological evidence for an association between use of wireless phones and tumor diseases. Pathophysiology, In Press, Corrected Proof.
 * 13) Seabury, David. An Update On SAR Standards And The Basic Requirements For SAR Assessment. Conformity(April, 2005): 3.
 * 14) How Cell-phone Radiation Works.  08 August 2001.  http://electronics.howstuffworks.com/cell-phone-radiation.htm
 * 15) Brain, Marshall, Jeff Tyson and Julia Layton.  "How Cell Phones Work: Cell Phone Frequencies"  14 November 2000. http://electronics.howstuffworks.com/cell-phone1.htm
 * 16) Federal Communications Commission FCC 02-305. Service Rules for Advanced Wireless Services in the 1.7 GHz and 2.1 GHz Bands. November 7, 2002. Retrieved on April 16, 2009.
 * 17) Industry Canada.  Spectrum Management and Telecommunications.  March 27, 2009.  http://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/h_sf06129.html. Retrieved on April 15th, 2009.
 * 18) LG Canada.  "LG Electronics Canada announces voluntary recall of the LG 150 mobile phone." January 27, 2009.  http://ca.lge.com/en/about/press_release/detail/PRE|MENU_6011_1.jhtml. Retrieved on April 15, 2009.
 * 19) Mobile Phone Functions For New Technicians. 01 August, 2007. http://forum.gsmhosting.com/vbb/index.php
 * 20) Acosta, Carlos.  Arlington Neurological Association.  Neurosurgical Treatment of Malignant Glioma.  June 18, 2005. http://www.dfw-neuronetwork.com/Malignant_Glioma.htm. Retrieved on April 15, 2005.
 * 21) Cellular Radiotelephone System for Different Cell Sizes. Richard H. Frenkiel (Bell Labs). Filed Sep 22, 1976, Issued March 13, 1979. http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=4144411.PN.&OS=PN/4144411&RS=PN/4144411
 * 22) Brain, Marshall, Jeff Tyson and Julia Layton.  "How Cell Phones Work: Cell Phone Codes"  14 November 2000. http://electronics.howstuffworks.com/cell-phone3.htm