Sunday, January 26, 2014

Should Wi-Fi be used in classrooms?

Teacher Newsmagazine  Volume 23, Number 1, September 2010  

Should Wi-Fi be used in classrooms?

By Lynn Quiring  
For years parents, teachers, administrators, and school boards have fought to keep cellular telephone transmitters away from their schools. Now we are installing them right into the classroom with Wi-Fi base stations.
The hot new craze in Internet access is Wi-Fi and its soon-to-be big brother Wi-Max. Wi-Fi is a wireless connection that allows users to access the Internet without the computer being connected to a cable. And yes, it’s very convenient. Imagine walking from the sofa to the bedroom with your laptop and never losing your connection. Imagine the freedom and flexibility afforded schools and office workers. No more ugly bothersome cables to tie you down. You’re free to roam the Internet with your fingers while roaming your home, school, or office with your feet. Freedom to move and freedom to surf. Perfect for the individual who is on the go and up-to-date with the latest technology. You can even have free Internet access at your local coffee shop. Same for airports. What a great idea. Or is it?
What exactly is Wi-Fi?  
Wi-Fi is a common term that stands for “wireless fidelity.” It simply means that a computer can access the Internet without wires or cables. In other words, it allows one to have a wireless connection to the Internet. It’s like taking a cell-phone base station and placing it in your home, schoolroom, or office area. Wi-Fi is basically the same type of connection as used to operate a cell phone.
Wi-Fi is really very similar to your cell phone. Radio signals are transmitted from the computer or Bluetooth device to a wireless router, sometimes called a wireless access point (WAP) or wireless local area network (WLAN). The router then sends the signal to the Internet through a cable modem. So this router or wireless access point is really the device responsible for transmitting the harmful radio waves. Any number of computers or devices can be configured to connect to one wireless router to make Internet connections. The workable distance is about a range of 300 feet or more from the wireless access point while most distances for good connections are maintained at about 100 feet. And, of course there are many variables that can affect this connection. Laptop computers and personal digital assistants (PDAs) are the most common devices utilizing Wi-Fi technology.
Wi-Fi emits radio frequencies 
Wireless connections emit radio frequency signals, or radiation, just like cell phones, cell-phone towers, and other wireless devices. Wi-Fi usually transmits its signal at frequencies in the range of 2.4GHz to 5 GHz. Cordless phones often transmit in the 2.4GHz to 5 GHz range, too, and this often causes the cordless phone to interfere with a wireless internet connection to a nearby computer. The Wi-Fi frequency is considerably higher than the frequencies used for cell phones, which operate in the 850 MHz to1900 MHz range. This higher frequency allows more data to be carried. However, as we’ll see later, it is not the frequency of the signal that may do damage to our health. So the higher Wi-Fi frequency isn’t really the issue at all when it comes to health considerations.
Wi-Fi hotspots now in schools 
Wi-Fi has become popular in the home, office, the airport, and coffee shops. Many cities are now installing “hot spots” where one can take a laptop computer and freely access the Internet over the provided network. This is what is known as a “hot spot.” It’s a place to make a wireless connection to the Internet. And they are springing up everywhere. Entire cities are becoming wireless allowing one to connect to the Internet from anywhere in the city. And due to the ease of convenience, Wi-Fi connections in schools are now becoming quite popular, too. No longer are computers hard-wired to a connection in a classroom. Connections are now virtual and allow the user, student or teacher, the freedom to connect anywhere in the school without the burden of being restricted by cable connections.
Why wireless connections can be harmful  
There are two potentially harmful mechanisms in which Wi-Fi users, including school children, may be harmed. The first mechanism involves the exposure to radiation from the distance or proximity of the user to the computer monitor. This form of exposure originates from the electromagnetic field being given off by the monitor itself and has nothing to do with the wireless connection. Electromagnetic radiation is given off by the computer screen regardless of whether the connection is wired or wireless. Any and all computer screens produce electromagnetic radiation. These electromagnetic fields can be substantial in strength and can reach levels much higher than the 1 milligauss (1 mG) threshold level of exposure recommended by experts as being safe. Such a field can easily be measured with an inexpensive instrument called a gauss meter.
The second mechanism of harm comes from the radiation or radio wave itself. The wireless signal, oscillating at 2.4 to 5 GHz, moves much too fast for the body to recognize. So this wave isn’t doing the damage. However, anytime any data or information is transmitted, say through our voice, through text messages, or through the sending of information, the data is packaged and “piggy-backed” onto the first wave. This creates a second carrier wave and this wave is called the information-carrying radio wave, or ICRW. It is the information-carrying radio wave that is producing the harm. Here’s how this happens. This second carrier wave, or ICRW, oscillates in a much lower Hertz (Hz) range that is easily recognized by the body. When the ICRW comes in contact with the body, the body recognizes this wave and responds to it as if this carrier wave were some type of foreign invader. When this happens certain physiologic changes occur which are very significant. First, at the cellular level, the cell membrane changes and becomes less permeable. This occurs because the active transport channels shut down as the cell goes into a protection mode. This loss of permeability means nutrients can’t get inside the cell where they are needed. In other words, the cell doesn’t get nourished.
Conversely, since the cell membrane is now less permeable, the toxins and free radicals that build up inside the cell as a natural part of our daily metabolism can’t get out. The buildup of toxins and free radicals inside the cell causes other problems. These toxic products damage the mitochondria inside the cell. If you’ll remember from biology class, the mitochondria are where energy for the body is produced. When this energy-producing process is damaged the cell begins to lose its ability to function.
In addition, cells lose their ability to communicate with one another. When one cell can’t communicate with another cell and messages don’t get sent or received, the body can’t respond properly to any type of stress, injury, or invasion. Furthermore, the DNA inside the cell becomes damaged. Fragments of DNA break off and form something called micronuclei. Micronuclei are precursors to cancer formation. And when enough energy is lost and when enough malnourishment occurs, the cell eventually becomes dysfunctional and dies. When enough cells die the tissues are affected. When enough tissue is affected organs become damaged and don’t work properly. And the cascade of damaging events begin that can lead to a multitude of symptoms and failure of the body's defense mechanisms to act appropriately.
The Wi-Fi problem  
Think of Wi-Fi this way. It’s really nothing more than a small version of a cell phone tower placed in the classroom or office. Or, it could be similar to having a cordless phone in your home with multiple handsets throughout the house. The base station is the access point and all the peripheral phones connect with it wirelessly. The radio frequency radiation being emitted is the same. The information-carrying radio wave is being transmitted continuously 24 hours a day. The connections from the computers and other wireless devices throughout the school, office, or home to the wireless access points cause any user around them, (children, teacher, staff, etc.) to be continuously exposed. Everyone in the building is caught in the crossfire of the continual access to the wireless access points. Even non-users are exposed because of the blanketing effect of these wireless access points throughout the building. So no one escapes the exposure.
In understanding the danger of Wi-Fi we must remember that it is not the type of device, in this case a wireless access point or router that is important. Rather it is the type of radio frequency radio waves that are being produced by the device that are significant. Whether from a wireless router, a cell phone, a cell phone tower, or personal digital assistant (PDA), electromagnetic frequencies are produced by all these devices. We must look at the technology being used by these devices and not the device itself as the problem. This should be the primary concern as we evaluate their safety, particularly in the classroom.
Another important aspect of Wi-Fi exposure is that of modulation. Modulation refers to whether or not the signal frequency is constant or pulsed. The new digital cell phones operate on a pulsed frequency, as does all wireless technology. Studies have shown that these pulsed signals are a greater risk than analog, non-pulsed signals.
Certainly, by the addition of any type of wireless we are adding to the burden of electropollution we are all currently exposed to. Special consideration should be given to the additional exposure that Wi-Fi technology would bring to those in a classroom, including the teachers, staff, and certainly students.
Children are more vulnerable  
Concern about the increased vulnerability to electropollution by children has valid reasoning. Since the skull bones of the head don’t fully harden until about age 22, the skull bones of a child’s head are softer than that of an adult. A softer head bone translates to easier penetration through the skull and into the head by radio frequency radiation. Furthermore, the head of a child contains more water since the brain is not fully developed. It would make sense then that water will act as a conductor to electromagnetic radiation increasing the possibility of even further damage. And since a child’s brain and nervous system is still developing, it only stands to reason that the potential damage would be greater since cells that are in a growing phase are more easily damaged.
And finally, exposing children in the elementary schoolroom will add to both the amount of electromagnetic radiation exposure and the accumulated length of exposure over their lifetime that they will be exposed. No one can argue that the children of today’s generation will be exposed to far greater amounts of electromagnetic radiation and will be exposed to it for a much longer period of time than any generation before. We simply don’t know the consequences of this increased and cumulative exposure. And it’s an experiment that we shouldn’t place our children in. Why set up these networks without understanding any of the long-term consequences? Did we not learn a lesson from the tobacco and asbestos industries? 
Lynn Quiring currently owns and operates Logical Health LLC. He can be contacted by e-mailing to lynnquiring@msn.com. 
References available on request.
Part 2 of this report will appear in the October issue of Teacher.  

La loi pour limiter l'exposition aux ondes électromagnétiques adoptée à l'Assemblée (Law to limit exposure to electromagnetic waves passed the Assembly)

La loi pour limiter l'exposition aux ondes électromagnétiques adoptée à l'Assemblée

Le Monde.fr |  • Mis à jour le  |
Une antenne-relais de téléphonie mobile.

Un an après un « enterrement de première classe » aux yeux des écologistes, quand elle avait purement et simplement disparu de l'agenda parlementaire, l'Assemblée a adopté, jeudi 23 septembre, la proposition de loi « relative à la sobriété, à la transparence et à la concertation en matière d'exposition aux ondes électromagnétiques », déposée par la députée du Val-de-Marne Europe écologie-Les Verts (EELV), Laurence Abeille.


Fruit d'un an de travail avec les socialistes et le gouvernement, le texte a été rejeté par l'opposition UMP, qui s'est élevé contre des mesures « sans justification sanitaire bien établie », « pénalisant les zones les moins denses du territoire dans l'accès au très haut débit », allant contre « l'innovation numérique ».

Pour le ministre de l'écologie, Philippe Martin, le texte adopté apparaît comme un« compromis constructif » et « une première réponse » aux préoccupations portant sur les ondes. Il devra être maintenant examiné au Sénat.

« ESPRIT DE PRÉCAUTION » 
Mercredi, quelques dizaines de militants « anti-ondes » avaient déployé une banderole sur le pont de la Concorde à Paris, face à l'Assemblée nationale :« Ondes : votez la loi ». « On a besoin de cette loi. Alors que la population est systématiquement contre l'installation d'antennes-relais, neuf fois sur dix, elle n'est pas entendue », a estimé Pascal Julien, adjoint EELV au maire du 18earrondissement de Paris, venu à cette manifestation avec son écharpe tricolore. 

La « mesure phare » du nouveau texte porté par les écologistes est « d'introduiredans la loi l'objectif de modération de l'exposition », résume Mme Abeille. « Ce sera un grand progrès, même si j'aurais aimé qu'on aille plus loin, ajoute-t-elle. Il est assez rare, en France, de légiférer dans un esprit de précaution. »

12 500 AUTORISATIONS POUR LA 4G
Sa proposition de loi s'inscrit dans un paysage marqué par la croissance exponentielle des technologies sans fil (téléphones mobiles, tablettes, Wi-Fi, babyphones…), génératrices de radiofréquences – des ondes électromagnétiques au milieu desquelles baigne la population, qu'elle soit ou non utilisatrice de ces équipements. Et le déploiement de la téléphonie mobile à très haut débit, la 4G, va encore accroître cette imprégnation.
Au 1er janvier 2014, annonce l'Agence nationale des fréquences (ANFR), le nombre de « sites » – c'est-à-dire d'emplacements d'antennes-relais – autorisés en France pour la 4G s'élevait, tous opérateurs confondus, à 12 525, soit une hausse de 3,8 % en un mois. A la même date, 38 000 sites d'antennes-relais étaient déjà autorisés pour la 3G, et autant pour la 2G.

Même s'il n'existe pas de consensus scientifique sur les risques potentiels des radiofréquences pour la santé, plusieurs avis et études ont appelé à la prudence. En 2011, l'Organisation mondiale de la santé (OMS) a classé les radiofréquences comme « cancérogènes possibles ». Et, en octobre 2013, l'Agence nationale desécurité sanitaire de l'alimentation, de l'environnement et du travail (Anses), sansconclure à « un effet sanitaire avéré », recommandait « de limiter les expositions de la population aux radiofréquences – en particulier des téléphones mobiles –, notamment pour les enfants et les utilisateurs intensifs ».

PAS D'ABAISSEMENT DES SEUILS
D'où la mise en avant d'un principe de « modération » de l'exposition. Le texte soumis aux députés est en réalité lui-même très modéré, par rapport à sa précédente version. Celle-ci, qui visait à un seuil d'exposition « aussi bas que raisonnablement possible », aurait conduit – conformément à la recommandation du Conseil de l'Europe – à fixer à 0,6 volt par mètre (V/m) la limite réglementaire. Celle-ci s'échelonne aujourd'hui entre 41 V/m et 61 V/m, en fonction des générations de téléphonie mobile.

Il n'est plus question, désormais, d'abaissement des seuils. « Le nouveau texte est surtout symbolique, estime Etienne Cendrier. Son mérite est de mettre un pied dans la porte, en introduisant un peu de régulation dans la toute puissance des opérateurs de téléphonie sans fil. »

C'est aussi l'analyse de l'association Pour une réglementation des implantations d'antennes-relais de téléphonie mobile (PRIARTéM). « Une avancée à petits pas vaut mieux que pas d'avancée du tout, juge sa présidente, Janine Le Calvez. Même si, plutôt qu'une modération, nous aurions préféré une réduction ou une limitation de l'exposition. »

POINTS « ATYPIQUES »
De fait, la modération annoncée vaut surtout pour les « points atypiques », ceux où les niveaux d'exposition « dépassent sensiblement la moyenne observée à l'échelle nationale ». Cette moyenne est de 1 V/m, mais, jusqu'à présent, l'ANFR ne retient comme « points atypiques » que ceux où l'exposition dépasse 6 V/m. Selon une étude du Comité opérationnel sur les ondes de téléphonie mobile (Copic), portant sur seize communes représentatives du territoire français et publiée en août 2013, les niveaux d'exposition sont « inférieurs à 0,7 V/m » dans 90 % des cas, mais quelques pics sont observés « jusqu'à 10 V/m à puissance maximale des émetteurs ».

Pour ces points « chauds », dont le recensement devra être effectué tous les ans, la proposition de loi « met en demeure l'exploitant de le résorber dans un délai maximal de six mois ». L'opérateur devra aussi « apporter la preuve de l'efficacité des mesures décidées ». Cela, sous peine d'un retrait d'autorisation.

ÉLECTROHYPERSENSIBILITÉ
Le texte, souligne Mme Abeille, met aussi l'accent sur « l'obligation de concertation et de transparence, au niveau local et départemental », lors de l'implantation ou de la modification d'installations radioélectriques. « Il s'agit, commente la députée, derétablir le rôle des maires, qui avaient été complètement exclus de la boucle décisionnelle. » 
D'autres mesures sont prévues, dont l'interdiction de « toute publicité », pour les téléphones portables ou autres terminaux comme les tablettes, ciblant les « enfants de moins de 14 ans ». Pour les plus jeunes,  les équipements Wi-FI seront interdits dans les crèches et les garderies. Les écologistes souhaitent que cette mesure soit étendue aux écoles maternelles, où ils  demandent que soit réalisée, pour toute nouvelle installation d'un réseau de télécommunications, « l'étude d'une solution de connexion filaire ».
Enfin, sur la question difficile des personnes souffrant d'électrohypersensibilité (EHS) aux champs électromagnétiques, le projet se contente de demander au gouvernement, dans un délai d'un an après la promulgation de la loi, un rapport sur« l'opportunité de créer des zones à rayonnements électromagnétiques limités, notamment en milieu urbain, les conditions de prise en compte de l'électrohypersensibilité en milieu professionnel et l'efficacité des dispositifs d'isolement aux ondes ».


« PEURS IRRAISONNÉES »
En limitant leurs objectifs d'encadrement des radiofréquences, les écologistes ont en fait cherché un compromis, acceptable par la ministre déléguée aux PME, à l'innovation et à l'économie numérique, Fleur Pellerin, et par celui de l'éducation nationale, Vincent Peillon, attaché à « faire entrer l'école dans l'ère du numérique ».

Le texte n'en inquiète pas moins les opérateurs. Le 10 janvier, huit organisations professionnelles du numérique « s'alarm[ai]ent et appell[ai]ent le législateur à faireévoluer un texte dont le principal effet en l'état serait de susciter peurs irraisonnées, tensions et contentieux autour des réseaux et des servicesnumériques mobile et sans fil ». Pour les signataires (Afdel, FFTelecoms, Fieec, Gitep, SFIB, Simavelec, Syntec Numérique et Uspii), la proposition de loi, si elle est votée, aura pour conséquence de « multiplier les obstacles au déploiement des réseaux mobile » et « à la disponibilité des infrastructures et des terminaux innovants plus économes en énergie et respectueux de l'environnement ».

Aussi en appellent-ils « à la sagesse du législateur pour établir un équilibre entre la nécessaire transparence vis-à-vis du public et l'impérieuse nécessité depromouvoir l'investissement et l'innovation dans le numérique ». Cela, soulignent-ils, « au bénéfice de la croissance, de la compétitivité, de l'attractivité des territoires et de l'emploi ».



Weekly Innovation: A Radiation Detector In Your Smartphone

Weekly Innovation: A Radiation Detector In Your Smartphone


by ALAN YU
January 23, 201411:05 AM

Scientists tested their radiation detection app on four smartphones, concluding that it works well enough to be a useful warning system for first responders.i
Scientists tested their radiation detection app on four smartphones, concluding that it works well enough to be a useful warning system for first responders.
Idaho National Laboratory
Scientists tested their radiation detection app on four smartphones, concluding that it works well enough to be a useful warning system for first responders.

Idaho National Laboratory

In our Weekly Innovation series, we pick an interesting idea, design or product that you may not have heard of yet. Do you have an innovation to share? Use our form.

A smartphone camera can make you a walking gamma ray detector. Without needing any extra hardware, you could get a warning on your phone when you're approaching potentially harmful levels of gamma radiation.

Scientists at Idaho National Laboratory created an Android app (the system is called CellRAD) for turning smartphone cameras into radiation detectors, and tested it with four smartphone models (Samsung Nexus S, Samsung Galaxy Nexus, Samsung SIII and LG Nexus 4).

They concluded that the phones have the processing power to detect gamma radiation with their built-in cameras and to measure levels on the phone. With the help of a program on a remote server, the app captures and measures an average energy level, then uses a model to figure out what types of radioactive material could be emitting the radiation. Basically, once your phone has been calibrated with the app, you'll have a radiation detector in your pocket.

"Up until fairly recently, people weren't carrying around cameras with computers attached to them pretty much all the time," says Joshua Cogliati, a research scientist and co-author of the recent paper announcing their findings. "That's why it's happening now."

The app was funded by a grant from the Department of Defense's Rapid Reaction Technology Office and could be useful for firefighters, police officers and other first responders, according to its creator.

The principle behind this isn't new — scientists know that charge-coupled devices (or CCDs used in cameras) can detect X-rays. But now our phones have the computing power to figure out what the source of radiation is, and eliminate false positives that can happen just because your phone is warm.


The U.S. Nuclear Regulatory Commission says members of the public shouldn't be exposed to more than 0.1 rem of radiation a year; Cogliati says the app will be able to quickly pick up a source before a person receives a dose of that amount, and it's not so sensitive that it'll start beeping at bananas. Of course it won't be as sensitive as a regular detector, but it's definitely enough to detect radiation before it reaches deadly levels and it's useful enough as a warning system, he says.

For example, say you know there's a large radioactive source somewhere in New York City.

"New York has people who do have radiation detectors, but they're not able to go quite everywhere," Cogliati says. "All of a sudden you might be able to push [radiation detectors] to all the police officers who have cell phones and suddenly you've just increased your coverage."

The scientists are considering a commercial partnership to develop the app for the general public. In the meantime, there are other apps that can give you an estimate of the gamma radiation around you.

Environmental Protection Agency (EPA) on Wireless Technology

Environmental Protection Agency (EPA) on Wireless Technology

This page describes the non-ionizing radiofrequency used for wireless technology.
On this page:

Overview

Wireless technology, especially in schools, has become an increasingly controversial topic. The steady increase in youth cell phone use and the location of cell towers, as well as the increased use of wireless networks and devices in schools, has made the potential effects of wireless technology on students’ health and safety a concern to many parents and educators.
The type of energy used in wireless technology is radio frequency (RF). RF radiation is non-ionizing. In other words, it is not strong enough to affect the structure of atoms it contacts.
RF can be dangerous at very high levels because it creates heat, and has the ability to heat tissue rapidly. This is the principle by which microwave ovens cook food. Cell phones and wireless networks produce RF, but not at levels that can cause significant heating. For cell towers, RF energy decreases rapidly with distance and ground-level exposures are typically well below exposure limits set by the Federal Communications Commission (FCC).
Wireless technology is still relatively new, and world-wide, researchers continue to study the effects of long-term exposure. To-date, the scientific evidence linking long-term use of cell phones to cancer or other health effects is not conclusive. More research is needed to clarify the question of safety.

Who is protecting you

U.S. Federal Communications Commission (FCC)

The FCC requires that all wireless communication devices sold in the United States follow safety guidelines that limit radiation exposure. The FCC also authorizes and licenses transmitters and facilities that generate RF and microwave radiation.
Major RF transmitting facilities under the jurisdiction of the FCC, such as radio and television broadcast stations, satellite-earth stations, experimental radio stations and certain cellular, PCS and paging facilities are required to undergo routine evaluation for RF compliance whenever an application is submitted to the FCC for construction or modification of a transmitting facility or renewal of a license.
FCC has authority to take action if a wireless phone produces hazardous levels of RF energy.

U.S. Food and Drug Administration (FDA)

FDA, in collaboration with the FCC, regulates wireless technology devices such as wireless computer networks and cellular phones. FDA monitors the health effects of wireless phones and has authority to take action if wireless phones are shown to emit RF at a level that is hazardous to the user.

What you can do to protect yourself

Although there is not sufficient evidence to conclude that there is a definite risk associated with long-term cell phone use, people who are concerned can take simple steps to reduce exposure:
  • Limit use – reducing the number/length of calls
  • Use "hands-free" devices – Using “hands-free” devices can help to keep mobile phones away from the head.

Resources

Cell Phone Facts:  Questions and Answers
March 30, 2012. U.S. Food and Drug Administration, Radiation-Emitting Products
This page provides consumers with basic facts and information about cell phone regulation.
Electromagnetic fields and public health: mobile telephones and their base stations exit EPA
March 30, 2012. 2000. World Health Organization
This fact sheet provides information about the health effects from exposure to radio frequency fields.
Frequently Asked Questions about Wi-Fi
November 28, 2012. Health Canada
Frequently asked questions about exposed to RF from wireless networks, including exposure in schools.
Mobile Telephony and Health Protection Advice exit EPA
March 30, 2012. UK Health Protection Agency
This page provides summary information about cell phones and base stations and provides links to other pages that provide general background information relating to the radio waves from phones and base stations, typical exposure levels of people using phones and living near base stations and relevant scientific and policy positions.
Radiofrequency Safety 
March 30, 2012. U.S. Federal Communications Commission
This page contains answers to many questions about cell phones and other wireless devices.
IEEE Engineering in Medicine and Biology Society, Committee on Man and Radiation exit EPA
March 30, 2012. Institute of Electronics and Electrical Engineers
This site provides a list of the Committee’s published papers and reports on the biological effects of exposure to electromagnetic radiation.