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MCPS Statement Concerning Deployment of Wireless Computing Technologies

It is important to note that the deployment of wireless computing technology in MCPS is occurring within a broader set of national educational practices in which federal and state educational policy efforts have prioritized providing students with greater access to technology as part of their everyday learning experiences. These ongoing efforts to improve student learning outcomes and provide students with the knowledge and skills to excel in college and careers demand that we incorporate greater use of mobile technology and digital content. Enabling wireless networks is the most impactful way to facilitate this transition. The wireless LAN systems in place in MCPS were specifically designed to provide greater wireless capacity and coverage to support online testing and mobile learning.

The devices that Montgomery County Public Schools (MCPS) uses in classrooms are fully compliant with Federal Communications Commission (FCC) guidelines. In fact, all wireless devices sold in the U.S. must go through a formal FCC approval process to ensure compliance with guidelines. Please review the information on the following website for further details: https://www.fcc.gov/guides/wireless-devices-and-health-concerns.

MCPS has made sure to review the exposure limits set by the FCC and the Occupational Safety and Health Administration and have ensured that the wireless networks in MCPS remain well below these established guidelines. MCPS will review the policy and procedures for wireless networks accordingly should new evidence about the safety of Wi-Fi be introduced.

Frequently Asked Questions

  1. Who conducted the Radiofrequency (RF) Monitoring for MCPS?

    Expand/Collapse Answer

    AECOM is a global provider of professional technical and management support services to a broad range of markets, including transportation, facilities, environmental and energy. With more than 31,000 employees around the world, AECOM is a leader in all of the key markets that it serves. AECOM provides a blend of global reach, local knowledge, innovation and technical excellence in delivering solutions that enhance and sustain the world’s built, natural and social environments. 

    More information on AECOM and its services can be found at www.aecom.com

  2. What protocol did AECOM use to evaluate RF levels in MCPS schools?

    Expand/Collapse Answer

    The evaluation monitoring conducted by AECOM for MCPS used the Narda Selective Radiation Meter Model 3006 (SRM 3006). The SRM 3006 was used to perform narrowband spectral analysis of application and individual classroom RF transmissions associated with the use of Chromebooks and access points (APs) across designated frequencies of 2 to 5 gigahertz (GHz). This device is able to focus on specific frequency bands so that the precise exposure levels from the 2.4 and 5 GHz bands of the access points could be accurately measured. More information on the SRM 3006 can be found at: http://www.narda-sts.us/products_highfreq_srm.php

    Monitoring was conducted while Chromebooks and access points were in use. Data were collected for six minutes while students were actively engaged in using their Chromebook devices. Monitoring involved approximately 550 millisecond sweeps, resulting in approximately 650 data sets being collected within the 6-minute monitoring time. Data were collected in 6-minute increments at set distances from the APs and Chromebook devices.

  3. What were the findings of the RF Monitoring conducted in MCPS schools?

    Expand/Collapse Answer

    Based on the data collected in this study and the analysis of the data, AECOM reached the following conclusions:

    None of the classroom readings exceeded FCC regulatory limits. In fact, all of the average power density results were several orders of magnitude below FCC regulatory limits. Note that measurements and regulatory limits were for 6-minute time-averaged, whole body exposure.

    Average power density results were also below recommended levels from non-regulatory agencies, including the Institute of Electrical and Electronics Engineers (IEEE), the International Commission on Non-Ionizing Radiation Protection (ICNIRP), and the Bioinitiative Report 2007.

    The values measured in this assessment were collected while students were actively using their Chromebooks.

    Thus, values measured represent actual and expected RF exposure during Chromebook usage.

    Because students are not expected to be using their Chromebooks continually during the day, actual RF exposure for any given day is expected to be similar or less than the measured values.

    Given the wide variety of scenarios evaluated and that the results were all several orders of magnitude below the regulatory limit, similar results would be expected in other MCPS schools and classrooms containing the same equipment evaluated.

  4. I heard from some parents that readings that activists took were higher than those conducted by MCPS? Why is that?

    Expand/Collapse Answer

    Activists who have been advocating against the usage of wireless networks have visited some schools and taken random readings using something called the Acoustimeter RF Meter Model AM-10. The Acoustimeter is sold by a company from England called EMFields who specializes in selling products that empower people to, “recognize, detect, and protect themselves against electromagnetic pollution from a wide variety of sources. If you aren't sure where to start looking, but want to protect yourselves from any of the following sources, use the images below and we'll do our best to find an answer tailored to your needs.” More information can be found here: http://www.emfields-solutions.com/index.asp.

    MCPS contacted EMFields to ask specifically if the Acoustimeter AM-10 is capable of isolating on a particular frequency band or if the meter readings include all signals. EMFields responded, “It’s a broad spectrum meter, not a frequency specific one (i.e., it measures the total exposure at all frequencies within that range). A frequency specific meter like a spectrum analyzer would typically set you back approx. 8-10 thousand pounds, and the Acoustimeter isn’t in that market.”

    This is important because the AM-10 is not capable of isolating on a particular frequency so one would not be able to determine what frequency in the 200MHz-8GHz band is causing the “graduated LED lights” to “update rapidly.” Because all fields are measured by the AM-10 it would be unclear as to what frequency was measured to determine the peak signal indicated by the graduated light.

    Manual found here: http://www.emfields-solutions.com/detectors/pdfs/acoustimeter-manual-v5w.pdf

  5. I read on a blog that the FCC guidelines are outdated. Is that true? 

    Expand/Collapse Answer

    The FCC guidelines are not outdated. The FCC works with international organizations to monitor the research on the health effects of Radiofrequency exposure. It relies on scientific evidence to justify its position. The FCC, the American Cancer Society (ACS), the Food and Drug Administration (FDA), and the National Cancer Institute (NCI)  all have conducted reviews as recently as 2013 and found that there is no basis to establish a different safety threshold.

    Please see the information from provided by the FCC:

        Some health and safety interest groups have interpreted certain reports to suggest that wireless device use may be linked to cancer and other illnesses, posing potentially greater risks for children than adults. While these assertions have gained increased public attention, currently no scientific evidence establishes a causal link between wireless device use and cancer or other illnesses. Those evaluating the potential risks of using wireless devices agree that more and longer-term studies should explore whether there is a better basis for RF safety standards than are currently used. The FCC closely monitors all of these study results. However, at this time, there is no basis on which to establish a different safety threshold than our current requirements.

    Please review information on this website for further details: https://www.fcc.gov/guides/wireless-devices-and-health-concerns.

  6. What do public health organizations have to say about radiofrequency?

    Expand/Collapse Answer

    The World Health Organization (WHO) has concluded that, “In the area of biological effects and medical applications of non-ionizing radiation approximately 25,000 articles have been published over the past 30 years. Scientific knowledge in this area is now more extensive than for most chemicals. Based on a recent in-depth review of the scientific literature, the WHO concluded that current evidence does not confirm the existence of any health consequences from exposure to low level electromagnetic fields.” Please review the information on the following website for further details:  http://www.who.int/peh-emf/about/WhatisEMF/en/index1.html.

    Public health bodies take action on well-designed and replicated studies. In reviewing the large body of existing scientific evidence, health organizations across the world have all reached the same conclusion: there are no proven negative health effects from Electromagnetic Fields (EMF) that is within existing safety guidelines. The following table summarizes international expert group evaluations of the biological and health effects reported in all animal and human cells (including human epidemiological investigations) exposed in vitro and in vivo to non-ionizing radiofrequency fields. The full review can be accessed here: http://www.mdpi.com/1660-4601/11/9/9376/htm

      

    Country

    Expert Group, Literature Evaluated, Year

    Conclusions

    Australia

    ARPANSA.
    All topics.
    2012–2014

    No substantiated evidence for health risk for people living near base stations. Insufficient evidence for higher risk for children.
    No need to reconsider exposure limits.

    Belgium

    Superior Health Council. All topics.
    2011–2014

    No proven health risks. Long-term health risks cannot be ruled out.

    Canada

    Health Canada.
    All topics.
    2012–1014

    Cell phone towers are not dangerous.
    No evidence of adverse effects from Wi-Fi.
    Since the last revision of safety code 6, no new adverse health effects have been established.

    Finland

    STUK. Some topics.
    2008–2014

    Mobile phone use is not detrimental to health.

    France

    ANSES. All topics.
    2013

    No new proven health effects.

    Germany

    SSK. All topics.
    2011

     

     

    DMF/BFS. All topics.
    2011

     

    Julich Res Institute.
    Children. 2009

    Discrepancy between scientific evidence and risk perception.
    No overall risks.

     

    Risk perception is linked to media coverage.

     

    No indications of adverse health effects in children.

    Latin
    America

    All topics.
    2010

    Thermal and non-thermal mechanisms were considered.
    Insufficient evidence for adverse health effects from in vitro and in vivo studies.

    Netherlands

    Health Council.
    All topics.
    2009–2013

    No evidence for medically unexplained symptoms.
    Limited data do not indicate adverse effect
    on brain and health of children.
    Insufficient and inconsistent association of tumors in brain and other regions of head.

    New Zealand

    NRL.
    All topics.
    2008

    No health problems when complied with international guidelines.
    A matter of informed choice
    for children’s use.

    Nordic
    Countries

    Denmark, Finland,
    Iceland, Norway and
    Sweden.
    All topics.
    2009–2013

    No scientific evidence for adverse health effects.
    If the number of fixed antennas is reduced, mobile phone will need to use higher power
    to maintain the connection, thereby the exposure of the general public may increase (2009).
    To date, do not show adverse health effects below the guidelines or limits adopted in the Nordic countries. (2013).

    Norway

    NIPH. All topics.
    2012

    No evidence that weak RF fields cause adverse health effects.
    Uncertainty in risk assessment is small.

    Spain

    CCARS.
    Wi-Fi.
    2011

    To date, no scientific evidence that exposure to the low emissions levels of these systems produces adverse health effects in school children.

    Sweden

    SSM/SSI.
    All topics.
    2008–2014

     

     

     

     

     

     

     

     

    FAS.
    All topics.
    2012

    Potential heating is the source for artifacts.
    The observed cancer risk estimates below the unity may indicate a “protective effect.”
    Some repetition studies were conducted. No adverse effects were reported.
    Most do not support earlier adverse effects.

     

    Overall data do not support increased cancer risk in mobile phone users.
    No new interaction mechanisms.

    Switzerland

    FOEN.
    All topics.
    2012

    No new confirmed health effects.
    “Absence of proof of health risks” does not automatically mean proof of their absence.

    Tanzania

    TCRA.
    All topics.
    2010

    No substantial evidence for harmful health effects.
    Many benefits of modern technology.

    UK

    HPA/PHE.
    All topics.
    2012–2013

     

     

     

     

    MTHR.
    All topics.
    2012

     

     

     

     

    IET.
    All topics.
    2013–2014

     

     

     

    ISLE of MAN.
    Phone Masts/
    Children. 2009

    No convincing evidence in adults or children for adverse effects below the recommended/guideline levels.
    Modulation has no significant role.

     

    No increased cancer risk from wireless technologies.
    No robust evidence of harmful effects.
    No definite demonstrable
    effects in children.

     

    No new robust evidence for adverse effects.
    Policy makers should consider all evidence including cost and benefits of mobile phone use.

     

    No definite demonstrable effects on children.

    USA

     

     

    ACS. Cancer.
    2012

     

    ACS. Cell Towers.
    2013

     

     

    FCC. All topics.
    2013

     

     

     

    FDA. All topics.
    2012

     

     

     

     

    NCI. Cancer.
    2013

    So far, no link between mobile phone use and cancer.

     

    No evidence that cell phone towers cause any health problems.

     

    No evidence for cancer or a variety of other problems, including headaches dizziness or memory loss.

     

    Studies on biological changes were not replicated.
    No evidence for health problems in adults, children and teenagers.

     

    Studies have not shown a consistent link with cancers of the brain, nerves, or other tissues of the head and neck cancers.

  7. My PTA is getting emails warning about “super industrial-strength” Wi-Fi. What is “super industrial-strength” Wi-Fi and should I be concerned?

    Expand/Collapse Answer

    The editors of the BioInitiative report and other groups use carefully selected wording in an effort to build support for their point of view. Using phrases like “industrial strength radiation,” “irradiating children,” “full body exposure to radiation,” “outdated FCC guidelines,” and “super strong industrial strength routers” are not based in fact.

    There is no such thing as “super industrial-strength” Wi-Fi. That term is used by bloggers to elicit a particular response. In reality, home-use access points and enterprise-use access points broadcast the same bands: 2.4 GHz and 5 GHz. The transmit power from the access point ranges from 2.5mW- 160mW in the 2.4 GHz band and 3.13 mW- 200 mW in the 5 GHz band. Furthermore, the access points deployed in MCPS schools are not even plugged into a wall outlet; they are powered by 7.5-15 watts of power over Ethernet. This amount of transmit power would not be considered industrial strength.

    The access points deployed in MCPS schools, however, do allow for more simultaneous connections per access point (approximately 30) than the typical home use access point that allows for 10 or more connections. This is because the chipsets in home-use access points are not able to process more than approximately 10 connections. The chipsets in enterprise-use access points are more advanced and are able to process up to 30 connections; additionally, enterprise-use access points have multiple antennas.  

  8. My PTA is getting emails warning that students are being constantly bombarded with radiation. What does this mean? 

    Expand/Collapse Answer

    Wireless networks use low powered radiofrequency transmitters called access points to communicate with low powered wireless internet cards located in the end device. The transmission occurs via a radio signal on either the 2.4 GHz or 5 GHz frequency. The time during which this transaction occurs is called the duty factor.

    The duty factor of a device is important because it quantifies the amount of time that the wireless device (access point or end device) is actually transmitting and, therefore, emitting a radio frequency. Logically, the duty factor for an access point is larger than that of an end device because the access point would need to service multiple devices in a classroom.

    The fact is that access points in schools are not constantly transmitting data so as a result, they would not constantly be sending out a radiofrequency signal. When bloggers claim, “constant bombardment,” they are confusing the transmission of data with the access point making itself available to wireless end devices. Wireless end devices do need to connect themselves to an access point in order to be able to communicate. The connection is accomplished when the access point sends out beacon frames and the end device recognizes the signal and connects to the network. These frames advertise the presence of an access point on a given network. The end device listens for these periodic beacons and connects to known networks. This process is called passive network scanning or discovery.

    The New Zealand Ministry of Health commissioned a study of radiofrequency fields in New Zealand schools and published a report titled Exposures to radiofrequency fields from Wi-Fi in New Zealand schools available here: http://www.moh.govt.nz/notebook/nbbooks.nsf/0/E56716622466312ECC257CAF006A3B3C/$file/wifi-in-nz-schools.pdf. The New Zealand report found that:

    Access points actively transmitted between 36 seconds and approximately 7 minutes per hour. The devices tested transmitted between 0.7 seconds and 33 seconds per hour with the average being 3 seconds. Moreover, the transmit power of devices tested varied between 5 and 17 milliwatts. The transmit power of access points varied between 3 and 28 milliwatts (0.028 watts).

      

  9. I’ve heard from some parents that Wi-Fi may cause cancer. What does the evidence about this say?

    Expand/Collapse Answer

    The International Agency for Research on Cancer (IARC) classification of exposure to radiofrequency as possibly carcinogenic was based on heavy mobile phone use. The decision to classify Radiofrequency as “possibly carcinogenic to humans” is explained in the IARC Monographs on the Evaluation of Carcinogenic Risks to Humans: Non-Ionizing Radiation, Part 2: Radiofrequency Electromagnetic Fields Volume 102, page 419. The IARC concludes that there is, “limited evidence in humans for the carcinogenicity of radiofrequency radiation.”

    The full report may be accessed here: http://monographs.iarc.fr/ENG/Monographs/vol102/mono102.pdf

    In the past 30 years, the IARC has evaluated the cancer-causing potential of more than 900 likely candidates, placing them into one of the following groups:

    • Group 1: Carcinogenic to humans (116 agents)

    • Group 2A: Probably carcinogenic to humans (73 agents)

     Group 2B: Possibly carcinogenic to humans (287 agents)

    • Group 3: Unclassifiable as to carcinogenicity in humans (503 agents)

    • Group 4: Probably not carcinogenic to humans (1 agent)

    Perhaps not surprisingly, based on how hard it can be to test these candidate carcinogens, most are listed as being of probable, possible, or unknown risk. Only a little over 100 are classified as “carcinogenic to humans.”

    Here is a sampling of Group 2B agents classified by the IARC: magnetic fields (extremely low-frequency), aloe vera (whole leaf extract), coconut oil, coffee, dry cleaning, engine exhaust (gasoline and diesel), ginkgo Biloba extract, nickel (metallic and alloys), pickled vegetables, talc-based body powder, titanium dioxide (found in personal care products and in sunscreen), and amaranth.

    According to the Office of the Provincial Health Officer in British Columbia the 2B classification was based on a group of studies that, “Reported an increased incidence of specific brain tumours for cell phone users reporting the most use (greater than or equal to 1640 hours over life). Past studies have also shown an increased risk of tumours on the same side as cell phone use in heavy users who used cell phones for 10 years or longer.  However, these findings are based on self-reported use, which can cause “recall bias” – when someone who has experienced a negative outcome is more likely to remember possible exposures than someone who has not had that outcome.” Again, this is cell phone use, not Wi-Fi.

    The Office of the Provincial Health Officer also states that, “Wi-Fi exposures are a small fraction (less than 1%) of radiation received during typical cell phone use. There is no convincing evidence that Wi-Fi exposures constitute a threat to the health of B.C. residents.” 

    Additionally, The Office of the Provincial Health Officer produced a video that discusses the concerns about Wi-Fi in schools that activists raise.

    The information may be accessed at the following link: http://www2.gov.bc.ca/gov/content/health/about-bc-s-health-care-system/office-of-the-provincial-health-officer/current-health-topics/radiofrequency-and-health/do-cell-phones-cause-cancer

    Using the Group 2B classification of the entire spectrum of radiofrequencies as an indication that Wi-Fi is harmful when the classification came about due to extremely heavy cell phone use and not Wi-Fi does not accurately represent the intention of the classification.

    The American Cancer Society also notes that testing to see if something can cause cancer often is difficult. For example, it is not ethical to test a substance by exposing people to it and seeing if they get cancer from it. That is why scientists must use other types of tests that may not always provide clear answers. These tests include both studies on animals and through epidemiologic studies of people. The information may be accessed at the following link: http://www.cancer.org/cancer/cancercauses/othercarcinogens/generalinformationaboutcarcinogens/known-and-probable-human-carcinogens 

  10. Why does MCPS not apply the Precautionary Principle and remove wireless networks in its schools?

    Expand/Collapse Answer

    The “Precautionary Principle” dictates that unless something is proven absolutely safe, then it should be avoided. However, it is important to note that, the “Precautionary Principle” is already implemented in the Wi-Fi guidelines and exposure limits set by WHO, FCC, Health Canada, Public Health England, and other public-health bodies. These organizations have distilled a deep body of research by scientists, doctors, and public health officials into current safety protocols. Additionally the radiofrequency measurements taken at MCPS schools are lower than the guidelines published in the BioInitiative Report.

    A majority of the evidence used by those advocating for the elimination of Wi-Fi in schools, comes from the BioInitiative Report.  This  report was compiled, self-edited, and published by Cindy Sage and David Carpenter in 2007 and claims to be based in science. One of the many organizations that have refuted the science behind the report is the Institute of Electrical Engineers, Inc., Engineering in Medicine and Biology Society, Committee on Man and Radiation (COMAR). The committee concluded that the weight of scientific evidence in the RF bioeffects literature does not support the safety limits recommended by the BioInitiative Group. For this reason, COMAR recommends that public health officials continue to base their policies on RF safety limits recommended by established and sanctioned international organizations such as the Institute of Electrical and Electronic Engineers International Committee on Electromagnetic Safety and the International Commission on Non-Ionizing Radiation Protection, which is formally related to WHO.

    The Australian Centre for Radiofrequency Bioeffects Research (ACRBR) published a position statement on the BioInitiative Report. The determined the following:

    Overall we think that the BioInitiative Report does not progress science, and would agree with the Health Council of the Netherlands that the BioInitiative Report is “not an objective and balanced reflection of the current state of scientific knowledge” (page 4). As it stands, it merely provides a set of views that are not consistent with the consensus of science, and it does not provide an analysis that is rigorous-enough to raise doubts about the scientific consensus.

    The full report can be accessed here: http://www.acrbr.org.au/FAQ/ACRBR%20Bioinitiative%20Report%2018%20Dec%202008.pdf  

    The above mentioned statement from the Health Council of the Netherlands:

    In view of the way the BioInitiative report was compiled, the selective use of scientific data and the other shortcomings mentioned above, the Committee concludes that the BioInitiative report is not an objective and balanced reflection of the current state of scientific knowledge. Therefore, the report does not provide any grounds for revising the current views as to the risks of exposure to electromagnetic fields.

    The full report can be found here: http://www.gezondheidsraad.nl/sites/default/files/200817E_0.pdf   

  1. Additional Information

    Expand this section to see some statements from major health organizations that have been involved in studying Radiofrequency for years but have not concluded that Radiofrequency poses any adverse health effects

    Expand/Collapse Answer

    Below are some statements from major health organizations that have been involved in studying Radiofrequency for years but have not concluded that Radiofrequency poses any adverse health effects:

    National Cancer Institute:  “there is currently no consistent evidence that non-ionizing radiation increases cancer risk

    http://www.cancer.gov/about-cancer/causes-prevention/risk/radiation/cell-phones-fact-sheet

    World Health Organization:  

    “To date, no adverse health effects have been established as being caused by mobile phone use.”

    “Studies to date provide no indication that environmental exposure to RF fields, such as from base stations, increases the risk of cancer or any other disease.”

    http://www.who.int/features/qa/30/en/

    Center for Disease Control:  

    “In the last 15 years, hundreds of new research studies have investigated whether health problems can be linked to cell phone use. Some of these studies have suggested the possibility that long-term, high cell phone use may be linked to certain types of brain cancer. These studies do not establish this link definitively.”

    http://www.cdc.gov/nceh/radiation/factsheets/224613_faq_cell-phones-and-your-health.pdf

    Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI 53226.

    Health physics metastudy

    “Unequivocally, the RF exposures from Wi-Fi and wireless networks are far below U.S. and international exposure limits for RF energy.”

    http://www.researchgate.net/publication/258102960_Wi-Fi_and_Health  

    Health Canada (Canadian federal health agency)

    “Based on scientific evidence, Health Canada has determined that low-level exposure to radiofrequency (RF) energy from Wi-Fi equipment is not dangerous to the public. This conclusion is consistent with the findings of other international bodies and regulators.”

    http://www.hc-sc.gc.ca/ewh-semt/radiation/cons/wifi/faq-eng.php

    Public Health England (UK federal health agency)

    “There is no consistent evidence to date that exposure to radio signals from Wi-Fi and WLANs adversely affects the health of the general population. The signals are very low power, typically 0.1 watt (100 milliwatts) in both the computer and the router (access point), and the results so far show exposures are well within the internationally-accepted guidelines from the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Based on current knowledge and experience, radio frequency (RF) exposures from Wi-Fi are likely to be lower than those from mobile phones.”

    “On the basis of the published studies and those carried out in-house, PHE sees no reason why Wi-Fi should not continue to be used in schools and in other places.”

    http://webarchive.nationalarchives.gov.uk/20140714084352/http://www.hpa.org.uk/webw/HPAweb&Page&HPAwebAutoListName/Page/1199451940308

    Non-Ionizing Radiations–Sources, Biological Effects, Emissions and Exposures

    NRPB has made many measurements of exposure levels at publicly accessible locations around base stations. One study [12] reported measurements taken at 118 locations from 17 different base station sites. Average exposures were found to be 0.00002% of the ICNIRP public exposure guidelines and at no location were exposure found to exceed 0.02% of the guidelines.

    The maximum exposure at any location was 0.00083 mWcm-2 (on a playing field 60 meters from a school building with an antenna on its roof). Typical power densities were less than 0.0001 mWcm-2 (less than 0.01% of the ICNIRP public exposure guidelines). (See Fig. 2) Power densities indoors were substantially less than power densities outdoors. When RF radiation from all sources (mobile phone, FM radio, TV, etc.) was taken into account the maximum power density at any site was less than 0.2% of the ICNIRP public exposure guidelines. [12, 13]  

    http://www.who.int/peh-emf/meetings/archive/en/keynote3ng.pdf

    Workgroup Report: Base Stations and Wireless Networks—Radiofrequency (RF) Exposures and Health Consequences

    The possibility of RF health effects has been investigated in epidemiology studies of cellular telephone users and workers in RF occupations, in experiments with animals exposed to cell-phone RF, and via biophysical consideration of cell-phone RF electric-field intensity and the effect of RF modulation schemes. As summarized here, these separate avenues of scientific investigation provide little support for adverse health effects arising from RF exposure at levels below current international standards. Moreover, radio and television broadcast waves have exposed populations to RF for > 50 years with little evidence of deleterious health consequences.

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1849947/

  2. See other studies done by school districts on this topic

    Expand/Collapse Answer

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