Office of the Chief Technology Officer → Frequently Asked Questions
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
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
View Appendix B Raw Data
as well as Appendix C Data Analysis
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.
on AECOM and its services can be found at www.aecom.com
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.
Based on the data collected in this study and the analysis
of the data, AECOM reached the following conclusions:
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.
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.
values measured in this assessment were collected while students were actively
using their Chromebooks.
values measured represent actual and expected RF exposure during Chromebook
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.
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
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
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
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
Expert Group, Literature Evaluated, Year
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.
Superior Health Council.
No proven health risks.
Long-term health risks cannot be ruled out.
Cell phone towers are not
No evidence of adverse effects from Wi-Fi.
Since the last revision of safety code 6, no new adverse health effects have
STUK. Some topics.
Mobile phone use is not
detrimental to health.
ANSES. All topics.
No new proven health
SSK. All topics.
DMF/BFS. All topics.
Julich Res Institute.
scientific evidence and risk perception.
No overall risks.
Risk perception is linked
to media coverage.
No indications of adverse
health effects in children.
Thermal and non-thermal
mechanisms were considered.
Insufficient evidence for adverse health effects from in vitro and in vivo
No evidence for medically
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.
No health problems when
complied with international guidelines.
A matter of informed choice
for children’s use.
Iceland, Norway and
No scientific evidence for
adverse health effects.
If the number of fixed antennas is reduced, mobile phone will need to use
to maintain the connection, thereby the exposure of the general public may
To date, do not show adverse health effects below the guidelines or limits
adopted in the Nordic countries. (2013).
NIPH. All topics.
No evidence that weak RF
fields cause adverse health effects.
Uncertainty in risk assessment is small.
To date, no scientific
evidence that exposure to the low emissions levels of these systems produces
adverse health effects in school children.
Potential heating is the
source for artifacts.
The observed cancer risk estimates below the unity may indicate a “protective
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.
No new confirmed health
“Absence of proof of health risks” does not automatically mean proof of their
No substantial evidence for
harmful health effects.
Many benefits of modern technology.
ISLE of MAN.
No convincing evidence in
adults or children for adverse effects below the recommended/guideline
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
Policy makers should consider all evidence including cost and benefits of
mobile phone use.
No definite demonstrable
effects on children.
ACS. Cell Towers.
FCC. All topics.
FDA. All topics.
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.
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
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.
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.
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).
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)
2B: Possibly carcinogenic to humans (287 agents)
• Group 3: Unclassifiable as to carcinogenicity in humans
• 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
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
The “Precautionary Principle” dictates that unless something
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
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
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
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:
Cancer Institute: “there is
currently no consistent evidence that non-ionizing radiation increases cancer
date, no adverse health effects have been established as being caused by mobile
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.”
for Disease Control:
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
of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI 53226.
the RF exposures from Wi-Fi and wireless networks are far below U.S. and
international exposure limits for RF energy.”
Canada (Canadian federal health agency)
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
Health England (UK federal health agency)
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.”
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
Radiations–Sources, Biological Effects, Emissions and Exposures
NRPB has made many measurements of exposure
levels at publicly accessible locations around base stations. One study 
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
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]
Workgroup Report: Base Stations and Wireless Networks—Radiofrequency (RF) Exposures
and Health Consequences
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.