A Wi-Fi system in a classroom is like having a cordless phone in your home with multiple handsets throughout the house. The base station is the headquarters, and all the peripheral phones connect with it wirelessly. A typical classroom may have a laptop for each student (for example 28 laptops for 28 students.) Wireless computers use transmitters to push data through the air, which gives resistance, and are less reliable than wired computer networks.  In a Wireless Local Area Network (WLAN), transformers send millions of bits of information to transmitters through the laptop antenna.  This data is packaged onto a signal and sent to a microwave antenna that is on the wall or ceiling in the room.  The wall/ceiling antenna downloads the information into its attached waveguide, which sends the information to computer users or to another antenna receiver/transmitter in the school for processing. 

The radiofrequency radiation is continuously transmitted while the system is on 24 hours a day every day. Connections from the computers and other wireless devices throughout the school to the wireless access points cause any user around it, (children, teacher, staff, etc.) to be continuously exposed. A child in a classroom can be irradiated simultaneously by any one computer associated with a different base station in the Wireless Local Area Network.

In a letter (link) dated February 24, 2000 from Bill P. Curry, Ph.D., Consulting Physicist at EMSciTek to Dr. Gary Brown, Dr. Curry provided investigation results from reviewing the microwave radiation environment for children learning in a classroom with computers on a Wireless Local Area Network (WLAN). Dr. Curry calculated an estimated radiation power density assuming 30 children working in a classroom with wireless computers. According to Dr. Curry, “I think one can conservatively say that any one child will receive a radiation dose commensurate with a radiation density of at least 6-8 microwatts per square centimeter.  Presumably, this will continue for the duration the child is in the classroom where the computers are being used, every school day.  I think this is likely to be a serious health hazard.”

Research has shown that biological effects from radiofrequency/microwave radiation exposure are dependent on compounding factors:

1.       The length of time a person is exposed to transmitters. In a Wi-Fi equipped school, children are exposed upon entry into the school and until they leave.  A child entering the school district in kindergarten may face 13 years of radiofrequency/microwave radiation exposure. 

2.       The distance between the transmitter and the person.  In a wireless classroom, transmitters and antennas could be found on the computer, printer, ceiling, walls, outside of classroom trailers, and outside of the main building.  Children could be as close as 1.5 feet away from a transmitter with using a wireless computer. 

3.       Frequency of the radiation is the third exposure factor.  The current radiofrequency/microwave radio signals in classrooms are in the 2.4 GHz to 5 GHz frequency range. Our bodies are made up of 65% water by weight and have a high absorption rate to radiofrequency radiation.  The rate of absorption of radiofrequency radiation in the body climbs as the frequency of radiation increases.