Me slides about cell phone radiation and stuff

1. Using different models and different distances (touching to
several centimeters), do cell phones emit harmful amounts of
radiation while making a call for people?
By Jason Xu

2. Rationale
 My topic is on the levels of microwaves cell phones
emit
 I thought it was intriguing how cell phones could
beam voices from such a long distance away
 Also I thought about if the waves would be damaging
to the head if you have hour long conversations
 If the cell tower is far away, the wave must be powerful

3. Research
 To start my hypothesis, I researched the following:
 Cell phones
 Cell phone calls
 Electromagnetic radiation
 Health effects

4. Hypothesis
 If different models of cell phones are making calls
from different distances (touching, 1cm, 2cm, 3cm,
and 5 cm), then their radiation (measured in
mW/cm2) will not be above industry standards and
will not have a significant impact on human health
(>5mW/cm2) because they cannot produce that much
power.

5. Control, Independent and
Dependant Variables
 Control group: Cell phone while not making a call
 Independent variable & units: Cell phone type and
distance (cm) from microwave meter
 Dependent variable & units: Microwave power density
(mW/cm2)
 Control variables & units: phone call, direction
(transmitter facing sensor), temperature (F),
humidity, radiometer

6. Materials
To conduct the experiment, I used
 3 cell phones
 (Samsung SGH-T239, Sony Ericsson W300i, LG KP500)
 A microwave meter
 (Technology Alternatives 7021 Cell sensor)
 A tissue box
 A ruler

7. Procedure
1. Buy/borrow materials: cell phones, microwave meter
2. Set up cell phone and meter with a tissue box (see images)
1. *The cell phone transmitter (the highest levels) will face the sensor*
3. Measure background radiation
4. Make a call with the phone
5. Measure microwave levels in mW/cm2 (non-ionizing radiation) with the
meter during the phone call
1. *Noting the peak microwave level to one decimal place*
6. Record microwave levels
7. Move meter back set amount and measure again
8. Repeat step 4-7 for all cell phone models
9. Compare data: are the levels higher than the standard?
10. Create a graph to visualize
11. Analyze data: Make a conclusion about the levels measured and their safety

8. Images
Making sure the
setup is correct
Sensor
Initial Setup (step 2)
Close up of cell phone, holder, and
sensor

9. More Images
Measuring the radiation levels while
Close up of radiation meter (in use) the cell phone is making a call

10. Data
 Link to data

11. Conclusion
 The problem was to see if different cell phones making
calls created harmful levels of radiation for people.
 The hypothesis was that cell phones would not create
harmful radiation and it was correct.
 From the data collected it can be concluded that cell
phones are not harmful when making calls.

12. Conclusion continued
 After collecting all my data from my experimentation,
some trends have observed
 As the radiation meter was farther from the cell phone, the
waves measured were lower in power.
 The maximum levels measured were well below safety limits
for the CCOHS
 It can be concluded from the data is that the levels are well below the
levels needed to be harmful for people
 In addition, the maximum readings were in a spike that
lasted for a few seconds
 The rest of the time levels were much lower than the spike
 In conclusion, cell phone’s electromagnetic radiation will
not hurt people.

13. What is happening?
 When cell phones make a call, they send out waves of
electromagnetic radiation (EMR).
 Cell phones create small amounts of radiation that can
be picked up by a meter.
 However, the waves are not strong enough to cause
significant changes to the body.
 Heating of body tissue

14. Control variables
 There were several control variables to ensure the
experiment would have valid results.
 The same call was sent to the same person, the cell
phone faced the same direction, the temperature and
humidity stayed the same and the radiometer itself did
not move
 Some possible sources of error are
 The power level of the waves does not stay constant and
the meter may not be entirely accurate
 The cell phone and/or meter may not have been
absolutely still during the whole experiment.

15. What else could be done
 Test more cell phones
 Conduct experiment again
 Try a different meter
 Test phones receiving calls too
 Have the cell phone face a different direction

16. Why does it matter
 There are good real life applications:
 Many people today use cell phones and usage has been
increasing as more people spend time with phones
close to their head and body
 Phones are becoming more powerful as there is more
phone call coverage across the world.
 Many could benefit from knowing if cell phones
become a hazard to human health

17. The End

 Any questions