PROJECT N°37
Free WLan everywhere = Free Health Problems for everyone?
Christoph Pieber, Dorothea Klemt, Stella Kowalsky
European School Brussels III
Boulevard du Triomphe 135, 1050 Ixelles, Belgique
S5 DE
Abstract
Free WLan is a buzzword of our modern times. Wherever we go, be it at home, at work, in restaurants
or cafes in hotels, in buses or trains, we expect to be connected to the internet with WLan. We took
this as a fact and asked ourselves, what does this means for our health? WLan uses electromagnetic
rays and their effects on human health are not entirely clear. While the European Commission
promotes WLan throughout Europe, already in 2011, the Council of Europe adopted a resolution that
strongly recommends not to install WLan in schools, because of possible negative health effects.
We wanted to make up our own mind and have set up a research design to assess possible effects of
electromagnetic rays caused by WLan electromagnetic rays/fields.
1
Do WiFi-rays (high frequency waves) affect the growing of garden cress?
Do they affect the cell division?
And if it affects the cress plants does it also affect human beings?
1. Introduction
Free WLan is a buzzword of our modern times. Wherever we go, be it at home, at work, in restaurants
or cafes in hotels, in buses or trains, we expect to be connected to the internet with WLan. We took
this as a fact and asked ourselves, what does this means for our health? WLan uses electromagnetic
rays and their effects on human health are not entirely clear. While the European Commission
promotes WLan throughout Europe, already in 2011, the Council of Europe adopted a resolution that
strongly recommends not to install WLan in schools, because of possible negative health effects.
We wanted to make up our own mind and have set up a research design to assess possible effects of
electromagnetic rays caused by WLan electromagnetic rays/fields.
Electromagnetic Waves
Wlan (Wireless Lan) is a wireless computer network using a wireless distribution method.
Electromagnetic waves are a form of energy waves that have both an electric and magnetic field.
Electromagnetic waves are classified according to their frequency. The different types of waves have
different uses and functions in our everyday lives. The most important of these is visible light, which
enables us to see.
Radio Waves: Radio waves have the longest wavelengths of all the electromagnetic waves. They range
from around a foot long to several miles long. Radio waves are often used to transmit data and have
been used for all sorts of applications including radio, satellites, radar, and computer networks.
Microwaves: Microwaves are shorter than radio waves with wavelengths measured in centimetres.
We use microwaves to cook food, transmit information, in radar that helps to predict the weather
wireless networks (WLan). Microwaves are useful in communication because they can penetrate
clouds, smoke, and light rain.
Microwaves are a form of electromagnetic radiation with wavelengths ranging from one meter to one
millimetre; with frequencies between 300 MHz (100 cm) and 300 GHz (0.1 cm).
2
First experimental series
2. Materials

Cress plate

Cress seeds

Water
3. Experimental set-up
One cress plate was put in a room in a house without WLan and the other cress plate was put besides
a router in another house.
We always watered the cress plants but did not measure the quantity of water nor the amount of
seeds.
We positioned the plates in a room with a lot of daylight and with a temperature of around 20 degrees.
3
4. Results and discussion
First trial series without WLan:
1. Day
2. Day
3. Day
4. Day
5. Day
6. Day
The cress plants grew normally.
Average height of the cress plant:
6.25 cm
Highest cress plant:
7.1 cm
Smallest cress plant:
5.4 cm
First trial series with WLan:
1. Day
2. Day
3. Day
4. Day
5. Day
6. Day
The cress plants didn’t grow on the edges of the plate.
Average height of the cress plants:
3.5 cm
Highest cress plant:
6.1 cm
Smallest cress plant:
0.9 cm
4
Do the rays of the WLan-Router affect the mitosis of the plant?
To verify whether the “Wifi-cress” did not grow abnormally by accident, we repeated the first series
several times. However, we did not measure the exact quantities of water and seeds, neither did we
record the temperature. Nevertheless, the WiFi-cress always showed abnormal growth.
Second experimental series
Materials

Cress plate

Cress seeds

Water

Thermometer

Scale
Experimental set-up
The basic set-up of the second series was identical to the set-up of the first series: One cress plate was
put in a room in a house without WLan and the other cress plate was put besides a WLan router in
another house.
Results and discussion
For the second series, we tried to obtain more reliable results by refining the set-up:
The cress plates were put in two different rooms with a lot of daylight and a temperature of around
20 degrees Celsius.
We did a test-try to determine how much water a cress plant needs per day. While we watered the
cress with the exactly same amount of water, we panned the plate carefully and we turned the plate
a quarter turn in the clockwise direction each time that we watered, because otherwise the cress
plants would grow into the direction of the daylight.
5
We also placed two thermometers in each room: one directly and permanently beside the plate and
the other one each time before we watered the plants for three minutes in the middle and on the
edges of the plate.
In addition, we watered and recorded the temperatures at the same time each day.
First trial series without WLan:
Days
Time
1. Day
2. Day
3. Day
4. Day
9:00
17:00
9:00
17:00
7:30
17:00
7:30
17:00
Room
temperature
19,3°C
21,1°C
20,1°C
21,2°C
19°C
21,8°C
19,3°C
17,9°C
Temperature in
the middle
19,4°C
20,4°C
20,3°C
18,2°C
17,3°C
20,3°C
17,9°C
17,8°C
Temperature
on the edges
19,4°C
21°C
20,1°C
19,4°C
17,9°C
21,1
18,3°C
18,8°C
Amount of
water
30ml
30ml
40ml
40ml
0ml
40ml
40ml
40ml
Picture
6
Days
Time
5. Day
6. Day
7. Day
8. Day
7:30
17:00
7:30
17:00
7:30
17:00
7:30
17:00
Room
temperature
18,2°C
21,3°C
18,6°C
20,2°C
18,8°C
20,3°C
20,8°C
20,5°C
Temperature in
the middle
16,6°C
18,9°C
17,4°C
19,6°C
17,5°C
19,2°C
18,7°C
18,2°C
Temperature
on the edges
17,3°C
19,6°C
17,3°C
19,1°C
17,4°C
19,1°C
19,8°C
18,3°C
Amount of
water
60ml
60ml
60ml
60ml
60ml
60ml
60ml
60ml
Picture
The cress plants grew normally.
Average height of the cress plants:
4,67cm
(4,1cm + 5,5cm + 2,7cm + 4,1cm + 5,2cm + 5,3cm + 3,5cm + 4,5cm + 5,3cm + 4,6cm + 4,4cm + 5,1cm +
5,5cm + 5,8cm + 4,4cm)/15
Highest cress plant:
5,8cm
Smallest cress plant:
2,7cm
7
First trial series with WLan:
At the moment, we cannot report the exact results. By accident, we took too much cress seeds for this
series, therefore the results achieved are not comparable.
After consulting Mrs Schallhorn, it was decided that we repeat the second trial series with WLan and
present the overall results during the meeting in Luxembourg.
5. Conclusion
According to the results achieved so far, our trial series did not provide evidence for our basic
hypothesis that WLan radio waves might affect the growing of cress plants. We cannot draw any
conclusions on the effects of those radio waves on human beings.
6. Bibliographical references
http://www.ducksters.com/science/physics/types_of_electromagnetic_waves.php
https://en.wikipedia.org/wiki/Microwave
7. Acknowledgements
We would like to thank Mrs Schallhorn for encouraging our participation and for her scientific support.
8