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How Does Microwave Radiation Affect Different Organisms?
Transcript of How Does Microwave Radiation Affect Different Organisms?
By: Roberto Panayotti, Alejandro Mendoza
This experiment will determine how microwave radiation affects plant life, fungi and bacteria.
Does microwave radiation destroy all life?
Will varying lengths of radiation affect organisms differently?
A microwave oven is a kitchen appliance that heats and cooks food by exposing it to electromagnetic radiation in the microwave spectrum. Microwave ovens heat food by producing radiation which is absorbed by water molecules in the food. This makes the water molecules vibrate and produce heat, which cooks the food.
Much has been said about the dangers of radiation in microwave ovens. An experiment shows that microwaved water given to a plant causes the plant to die within days; however, another identical plant given water that was boiled on a conventional stove grew normally during the same time period.
Therefore I have to ask the following questions: Does microwave radiation affect the cooked food? Does microwave radiation destroy all life forms?
Any life exposed 30 seconds in the microwave will not be able to grow at all.
Independent Variables: What I changed is the amount of radiation the different life organisms were exposed to.
Dependent Variables: What I measured in the case of the radish seeds is the growth of the plants. In the case of the yeast ( fungi ) is how vigorous the reaction and the amount of bubbles were. In the case of the bacteria is the amount and size of colonies grown.
Control Variable: What I kept the same was
Radish seeds: amount of water, the setting, time of exposure, amount of sunlight, quality of soil and the amount of seeds.
Yeast ( Fungi ): amount of water, amount of yeast, water temperature and the time of exposure.
Bacteria: the place of collection, the setting, the room temperature and the time of exposure.
1- Packet of radish seeds
2- Paper towels
3- Four small containers filled with sterilized potting soil
4- Four packets of bakers’ yeast
Four small bowls
5- Four prepared Petri dishes with agar
6- Sterilized swabs
9- Notepad and pen
Procedure: Radish Seeds
1- Plant several radish seeds in a small container. Put them in a sunny, warm location. This is the control sample.
2- Place several more radish seeds on a paper towel. Microwave the seeds for five seconds.
3- Plant these seeds in another pot and place in the same location as the control group.
4- Repeat Step 2 and 3 for two more samples, except microwave one group of seeds for fifteen seconds and the other for thirty seconds.
5- Tend the samples by watering the pots once a day and ensuring they get enough sunlight.
6- Take pictures everyday and note if and how quickly the samples grow.
Procedure: Bakers Yeast
1- Dump a packet of bakers' yeast into a small bowl of warm water. Stir. This is the control sample.
2- Take note of how long it takes for the yeast to bubble up and how vigorous the reaction is. Take photos.
3- Dump another packet of bakers' yeast onto a plate. Microwave for five seconds.
4- Mix this yeast into another bowl of warm water. Repeat Step 2.
5- Repeat steps 3 and 4 for the other packets of yeast, except microwave one sample for fifteen seconds and the other for thirty seconds.
1- Wearing gloves, use the sterilized swab to collect a sample of bacteria and swab it on a prepared Petri dish. Good places to find bacteria are areas where lots of people touch something, like doorknobs, faucets or money bills. Seal the dish and label it "control." Put it in a warm, dark place. This is your control sample.
2- Swab another sample from the exact location as the control sample. Smear it on another Petri dish. Seal and label the dish. Place it in a warm, dark place.
3- Repeat Step 2 for the other two samples.
4- Let the samples alone overnight.
5- Take one sample out (not the control) and microwave it for five seconds. Place it back in the warm, dark place.
6- Repeat Step 5 for the other two samples, except microwave one for fifteen seconds and the other for thirty seconds.
7- After another day, take out all the samples. Note how many colonies of bacteria are growing and their size.
8- Analyze all this data. Does microwave radiation affect all life equally? Does time matter? How does each type of organism respond to the radiation?
Analysis: Plants ( Radish Seeds )
1- In the pictures and the graph provided you can notice that the control sample radish seeds ( not microwaved ) were the plants that grew the highest ( 9cms ) and the healthiest.
2- The seeds that were microwaved for 5s grew up to 8cms.
3- The seeds that were microwaved for 15s grew up to 7.5cms, and didn’t look healthy.
4- The seeds that were microwaved for 30s didn’t grow at all.
Analysis: Bakers Yeast
1- In the pictures provided you can observe that the control sample yeast ( not microwaved ) was the one that grew the most. When mixed with warm water, the yeast grew more vigorously and a great amount of tiny bubbles surfaced.
2- The yeast that was microwaved for 5s grew almost the same as the control sample, but the reaction was not vigorous and the bubbles were not as many as the control sample. You can observe some deflated areas.
3- The yeast that was microwaved for 15s didn’t grow as much as the first two samples. The reaction was less vigorous with a lot less bubbles. You can observe more deflated areas than the 5s sample.
4- The yeast that was microwaved for 30s did not grow at all compared to the first 3 samples. There was no reaction at all and no bubbles were formed.
Analysis: Bacteria ( Petri Dish )
In the pictures provided you can observe that the control sample of bacteria ( not microwaved ) was the one that grew the most. As you can observe there are more and bigger bacteria colonies than the rest of samples.
The bacteria that was microwaved for 5s grew up a couple of big colonies and many more scattered in the dish.
The bacteria that was microwaved for 15s grew up only small colonies on one side of the dish.
The bacteria that was microwaved for 30s didn’t grow colonies at all.
NOTE: it is interesting to observe how bacteria and worms grew in the control sample ( not microwaved ) from smearing a swab on a doorknob or a money bill and placing in the prepared Petri Dish.
From this experiment I can conclude that microwave radiation does affect any type of life. The radish seeds, the yeast and the bacteria all grew normally in the control ( not microwaved ) samples, where as the seeds, yeast and bacteria didn’t grow at all when microwaved during 30s.
I can also conclude that the longer amount of time a living organism is exposed to microwave radiation, the more it is affected. You can observe this from the growth of the living organisms microwaved during 5s and 15s. The organisms microwaved less time grew more than those microwaved for a longer time.
Therefore, I conclude that my hypothesis was correct, since no form of life grew at all when microwaved during 30s.
Tests performed by manufacturers at a distance of 2 inches show that microwave radiation does leak out of the devices no matter how expensive or well made the model is.
Much research is being made on microwaves and how they might affect the human body. The fact that many scientific questions about exposure to low-levels of microwaves are not yet answered require FDA to continue the enforcement of radiation protection requirements. If you use a microwave oven it would be a good idea to stand back.