EM Radiation on plant growth

[Feanaro Saralonde]

Im working on a project that doesn't have a due date yet, but I estimate it to be in April. My idea: The effect of EM radiation on plant growth and different methods of stopping the radiation from reaching the plant.

I need help figuring out which electronic devices emit how much EM radiation, ideas to use as protection, and suggestions on what plant to use (I was thinking bean or radish).

Also, if you have any other Ideas or comments on my project idea, please let me know as well.

Thanks in advance.

FS

[SciB]

Hi FS,

That's a very important question you are asking and I hope we can help you design a good project to test your hypothesis.

First--what are sources of EM radiation [EMR, for short]? The first thing i think of is a cell phone because they were in the news a couple years ago when their EMR was supposedly linked to brain cancer. That appears to be disproved now, but we don't know what might happen 20 years out because people haven't been using them that long.

Really, before you can think about devices as sources of EMR, you need to define the range of frequencies that scientists recognize as being potentially harmful to cells. Technically EMR is any form of energy traveling through space--microwaves, radio waves, visible light, UV, X-rays and gamma rays--so you need to first define the region of interest.

There are also magnetic fields, but that's a whole different area of study--although just as interesting, i think.

I am assuming you are thinking about radio frequency emissions in the megaherz range or maybe gigaherz also. Cell phones, routers and blue-tooth devices all use this frequency range but their outputs are in the microwatt range, I think. Maybe a strong walkie-talkie might have an output in milliwatts. You'll have to do some more research into this. I have no idea what field strength you would need to have any hope of seeing a visible effect on a plant in a relatively short time. Weak radiation effects often take years to show up because they affect the DNA and the effects are cumulative.

I wonder if you shouldn't test your theory on a small living organism such as daphnia [http://en.wikipedia.org/wiki/Daphnia] which are often used in science fairs to show effects of drugs, alcohol. light, magnetism, etc. You do need a microscope with a camera to observe them and take pictures, but they are easy to grow and you can see their heart action, blood flow, and the activity of other organs through their clear exoskeleton.

I hope this is helpful to you. Think about it and get back to us and we will guide you into a good project.

Sybee

[Feanaro Saralonde]

Sybee,

I forgot about daphnia. Those could work too, if not better, but I will have to get hold of a microscope.

I did some research, and I found that Ionizing radiation (as opposed to nonionizing) ionizes atoms and breaks chemical bonds. UV and up is considered Ionizing. Cell phones emit radio waves to send and receive signals. The chart displayed says that UV radiation/ionizing radiation begins around 10^16 Hz. This is saying that the radio waves that are emitted by cell phones aren't ionizing.

They can cause heat related reactions though, take microwave radiation for an example. The article also says that studies continue to contradict each other, but not about radiation being absorbed into cells, but about how much radiation is considered harmful and over what period of time. This is especially debated because of the seemingly harmless nonionizing radiation emitted by cell phones. The long term effects are the ones in question, so that makes me doubt the viability of my project showing much evidence in even a month or two, especially when the FCC places limits on the amount of radiation emitted by the devices. The specific absorption rate limit in the US is 1.6 watts per Kilo.

It does make me wonder if something larger, a tablet, computer or even a TV would work better.

I found this link to test the SAR of devices by the FCC: http://transition.fcc.gov/oet/ea/fccid/

The only thing that it would identify was contained in a Wii at 2412.0 to 2462.0 Mhz

Any reccomendations?

FS

[SciB]

Hi FS,

Remember, the effects of EMR depend on type, distance and duration. If you expose the daphnia to EMR continuously at close range you may be able to speed up the effects considerably. You are doing the right thing looking for a source that has the highest wattage output.

Do some online searching and see if there is anything published on the effects of radio-frequency EMR on daphnia. If not, you could be the first to show a biological change! I don't know what you would measure as an effect of EMR--activity? breeding? heart rate? survival? change in morphology?

I hope you can do this project because it really sounds interesting and promising. Make it work!

Best regards,

Sybee

[Feanaro Saralonde]

Sybee,

Originally, I had plants in mind and was going to test growth, and if necessary, survival. I am not very familiar with daphnia, but I know that they are relatively common to use with biology science fair projects. If growth is a viable dependant variable, I will use that. Otherwise, I would probably use survival. I did find this article though, that makes me think that survival may not be a good variable either:

The influence of electromagnetic radiation of industrial frequency on survival, efficiency, physiological parameters of Daphnia magna (Straus) was investigated. The electromagnetic field with intensity of a magnetic component 15 microTl and an electrical one 12 kV/m was generated. The research was carried out in acute and chronic experiments. The experimental group was exposed to electromagnetic radiation for 8 hours daily for 30 days. As a result of the study it was revealed that the influence of electromagnetic radiation with the given parameters did not have a lethal effect on the test objects. It was found that electromagnetic radiation negatively affected Daphnia fertility. On the average, a real fertility of the Daphnia in the experimental unit was 26.32% compared to the control. The age of puberty in the experiment increased twice in comparison with the control. Translated from Russian.
http://www.ncbi.nlm.nih.gov/pubmed/14658289

I don't understand all of this, or at least some of the measurements that they are using, like "industrial frequency" and the micro Tl thing.
I'm not sure if this is what I am looking for or not, but all this told me was that this has been tested, and that only fertility was affected in this experiment. At this point, what are your opinions?

[SciB]

The translation from the Russian is probably why you can’t understand it. I think ‘microTl’ stands for ‘microTesla’ which is a unit of magnetic field strength.

Plants are pretty resistant to radiation, both nonionizing and ionizing. That’s why I suggested using daphnia which are more sensitive and also have more animal features to measure so that you might be able to extrapolate your results to humans. You might also use the roundworm Caenorhabditis [http://en.wikipedia.org/wiki/Caenorhabditis_elegans] or that old genetic standby, the fruit fly, Drosophila [http://en.wikipedia.org/wiki/Drosophila_melanogaster].

I’m trying to think of test organisms that you could expose to EMR for a few weeks and see a statistically significant alteration in something measurable. Maybe there is no organism that sensitive unless you could use a really high EMR field strength. Is there any way to use a wave guide and concentrate the output energy from you Wii console into a smaller stronger beam? If you could give a high enough ‘dose’ of EMR then you would see a definite effect on something and what that something might be we don’t know—that would be the interesting part.

I wish I could give you a clearer idea how to go about this project because I really think it is worth doing. I’m just not sure how to do it! You need a stronger source of EMR.

Let us know what you decide and we can help you pick the right controls, doses, measurements, etc.

Sybee

[Feanaro Saralonde]

I haven't been in school for a while, but when I do, ill ask my science teacher for advice about which "test subjects" to use. I was thinking that it would probably be easier to have multiple sources of EM radiation instead of making one stronger or using one larger one. For an example, I could have the controll in the most isolated environment EM radiation wise.

I could do multiple experimental groups with a different number of devices, and do maybe 2 trials each. One with a cell phone, one with a computer, another with both, or something like that. Do you think that that would have the desired effect?

[SandbaggerOne]

Different sources will introduce lots of variables like intensity and frequency of EMR. You won't know which variable causes any observed effects. This could be a limitation of the approach you describe.

Cheers,
Colin

[SciB]

Yeah, I agree with Colin that at least at first you should limit your variables. Also, do you have any way of measuring field strength quantitatively? If all you have to go on is the equipment rating, that could be way off, depending on the age of the device. Maybe you could borrow a meter from someone in the engineering department.

I understand why you want to compare several devices. I would want to do that too; but first i think you need to be sure that your test organism will show a measurable response to the EMR in the time that you have to do the experiment. Do some more reading. Find out what cell, animal, algae, or whatever that scientists are using to study the effects of EMR on living organisms. There might be some critter that is very sensitive to EMR. You don't want to go to all the trouble of setting up these experiments if there is no chance of seeing an effect.

Get back to us with your plan and we will help you troubleshoot it and get this project going.

Regards,

Sybee

[SandbaggerOne]

Right, better would be to test one device and make the variable distance or presence of or type of barrier. That would be easier to interpret.

Cheers,
Colin

[kbmcgill]

Did anyone ever complete this experiment of EM Radiation on plant growth? I was thinking of doing something similar and wondered how you constructed your experiment.

Thank you.

RM