Judging possible wifi health risks?

February 5, 2007 8:45 AM

My question has two parts: -What are some reliable resources that would allow me to form an intelligent opinion about the possible health-risks of wifi exposure - specifically for a pregnant woman surfing the 'net wirelessly from a laptop for a few hours a day. -Where is the built-in wifi antenna on a Dell Inspiron 1150 laptop? (If it's in the screen vs. the keyboard area, then at least it's a few inches further from the womb-area - but again, I have no idea if that even matters).

Our general attitude can be summed up as follows:

-Right now, we're not paranoid about having electronic devices (TV, computers, cell-phones) in the same room as us, but we probably wouldn't stand directly in front of a microwave while nuking our morning cereal
-We let our two-year-old son talk to his grandparents on the cordless phone, but not a cellphone.

So, we're looking for a range of opinions, focusing on the less-radical ends of the spectrum.

posted by ericbop to health & fitness (28 comments total)

Radiation basics discusses the difference between non-ionizing and ionizing radiation. Those terms should provide plenty of googling goodness for you. In general, it seems highly likely that there are zero damaging effects on living tissue from non-ionizing radiation, such as wifi, cordless phones, cell phones, TV signals, etc.

A recent study over a period of 21 years showed no link between cell phone use and cancer.
posted by knave at 9:08 AM on February 5, 2007

Decent article here (PDF). If youre this concerned will milliwatt radio radiation I would also be asking the same question of televisions, baby monitors, microwaves, cell phones (which are 10x stronger), high power electric cables, high power radio antennas nearby, cordless phones, remote key unlock/starters, etc for the unborn.
posted by damn dirty ape at 9:09 AM on February 5, 2007

To follow up on the ionizing vs non-ionizing thing: there is no known mechanism by which non-ionizing radiation can cause cellular damage (other than just heating them up, which you would notice). So either millions of scientists and thousands of studies have completely missed the ball on a very basic thing, or you're fine.
posted by 0xFCAF at 9:27 AM on February 5, 2007

all of those items that damn dirty ape listed above would certainly fall into the same category as a wireless laptop: i.e. things that so far I don't have a problem using, but really wouldn't want strapped to my wife's belly (or my son's head) for hours on end, so to speak. is the basic idea that proximity really wouldn't play a part in any theoretical health risks? that a cellphone or a wifi antenna would, for better or for worse, pose the same risk across the room as it would inches from a person? that seems counterintuitive to me.
posted by ericbop at 9:42 AM on February 5, 2007 [1 favorite]

What 0xFCAF said.

Yes, there's "a chance" that everyone is wrong. There's also "a chance" that your ceiling is going to fall on you while pregnant.

The latter chance is billions of times more likely. If you want to decrease your risk, spend your time having your house's ceilings inspected.
posted by dmd at 9:43 AM on February 5, 2007

You should be asking yourself the inverse question: What leads you to believe in the first place that exposure to electromagnetic radiation is something to be so concerned about? There was a recent period of hysteria about EM radiation and cell-phone towers and whatnot but it has proved to be unfounded, as knave shows, and nobody knows how this tulip-like hysteria got started.

Also, EM radiation is in the air whether or not you turn on your radio or Wi-Fi enabled laptop or whatever. Every single radio station is broadcasting through your body right now.

Also, your cordless phone is broadcasting back to the base station.
posted by vacapinta at 9:57 AM on February 5, 2007

Visible light is also a form of primarily non-ionizing electromagnetic radiation. Each photon of visible light actually has more energy than radio frequency photons. So before you worry about electronic devices, you might consider keeping your wife and child in the dark all the time.
posted by grouse at 10:06 AM on February 5, 2007 [1 favorite]

FWIW, my sister had to be in the hospital for a month or two before her baby was born and they supplied wireless internet access so she could surf the net with her laptop from her bed.
posted by Diskeater at 10:08 AM on February 5, 2007

As a serious, non-absurd suggestion, wear sunblock every time you go out on the street. Ultraviolet rays are ionizing, and do cause real damage to skin, which sometimes causes skin cancer. I don't think it will penetrate into the womb, though.
posted by grouse at 10:12 AM on February 5, 2007

ericbop, you're right to think that proximity matters, in terms of radiation. In fact, intensity of radiation exposure is proportional to the square of your distance from the radiation source. So the further away, the better, definitely!

However, the type of radiation also matters. As far as we know today, no source of non-ionizing radiation can cause cellular damage, regardless of intensity! Ok, there's an exception -- radiation around the microwave range, like your microwave oven, will cause a warming effect. No big surprise there. If the warming is intense enough, there will be heat damage. However, none of the mutative effects of ionizing radiation like UV light, x-rays, gamma-rays will be found from the most intense non-ionizing source.

Finally, as others have pointed out, you're practically bathing in this type of radiation all the time anyway. Cell phone towers, television and radio broadcasts, other people's cell phones and wifi networks, the EMF noise from every electronic device. It's all around and through you all the time. If it was capable of damage, you'd have the damaging effects with or without your personal use of wireless devices.
posted by knave at 10:39 AM on February 5, 2007 [1 favorite]

No offense, but this is a perfect example of a mis-aligned threat perception.

...you are worrying about hazards that either do not exist at all, or are so microscopic as to essentially not exist. In the absence of an identifiable real threat, humans seem to automatically create new threats out of nothingness -- as though the brain is wired to have a threat, and if no threat exists, it will make one.

Not standing in front of the microwave? Are you serious? You do realize that, right now, you are being washed by an unending stream of cosmic rays (which are ionizing) and even radiation from the natural dirt under your feet (also ionizing).

I'm prepared to bet that the stress hormones you're making while worrying about this stuff will have a far more significant impact on your unborn child than whether you use 801.11b or not.

There are far more meaningful things you can do with your time, like take care of your own nutrition, make sure your furnace is burning cleanly, and the like.
posted by aramaic at 10:44 AM on February 5, 2007 [3 favorites]

Not standing in front of the microwave? Are you serious?

Not to mention that your microwave has a built-in Faraday Cage to keep the microwaves inside.
posted by knave at 10:56 AM on February 5, 2007

If WiFi were dangerous, the game would already be lost. As a reference point, the legal power limit for a WiFi antenna is 100 mW. A 100W light bulb is emitting 10,000 times more power, and is definitely not limited to the visible spectrum. Sunlight is multiple times more powerful that that, and includes all sorts of nasty things like cosmic rays and ultraviolet light.

You're living at the bottom of a lake and worrying about a rain cloud that might make you wetter than you already are.
posted by 0xFCAF at 10:58 AM on February 5, 2007

aramaic, thanks for your advice about how I spend my time. rest assured that the five minutes I'm spending on AskMeFi to seek out the advice of this normally helpful community is about the extent of it. So I'll have plenty of time left to:

-inspect my ceilings
-keep my wife and child in the dark
-take care of my own nutrition
-make sure my furnace is burning cleanly

and plenty of other suggestions that might also range from irrelevant to sarcastic to snarky to dickish.

thanks at least to knave for being informative without being judgemental (or defensive?).
posted by ericbop at 11:19 AM on February 5, 2007

No need to be so touchy. I wasn't being judgmental myself, although I can't speak for others. Personally, I think it is good to wonder about the risks of various activities in our modern world. But it only makes since to consider the risk as relative to other risks. Obviously it would be absurd to worry about the risk from visible light, but you should now see that it is just as absurd to worry about a WiFi antenna.
posted by grouse at 11:59 AM on February 5, 2007

Could someone who argues that there is no possible way that non ionizing radiation could do any harm whatsoever explain this study to me?
posted by davar at 12:33 PM on February 5, 2007

davar: see knave's comment.
posted by matthewr at 12:43 PM on February 5, 2007

Matthewr: so the dangers from microwaves are only heat damage? But then, how much heat are we talking about here? Would just sitting around a campfire be much warmer than sitting in front of a microwave? Does sitting around a campfire cause the same diseases in rats?
posted by davar at 1:15 PM on February 5, 2007

davar: I hope that I am qualified to answer your question, despite never arguing that there is "no possible way" that non-ionizing radiation could do harm. I think that is a straw man, as several people here have pointed out that the question is one of relative risk. I would not argue that microwave radiation could not possibly do harm, just as I would not argue that visible light could not possibly harm either.

My conclusions are the same as this review which did not look at your specific study, but included several other studies of the health effects of microwaves on the brain:

At present, there is little evidence that pulsed or continuous microwave exposure in the non-thermal range confers elevated risk to the health of the brain. Although microwave-brain interactions have previously been reported in various fields of research, many of the positive experimental results reviewed above can be attributed to thermal effects evoked by SAR levels well above those relevant for mobile communication. For example, the blood–brain barrier disturbances, which have reproducibly been shown following microwave exposure in rodents, were closely related to local temperature elevations in the brain (see Section 6). As long as the power of microwave absorption remains below the threshold for thermal heating (Section 1), blood–brain barrier effects do not seem to be relevant for mobile communication. Similar to blood–brain barrier disturbances, many of the biochemical and electrophysiological effects described above were associated with thermal changes in the brain. Controversial observations should, therefore, be tested for spurious temperature effects.

From the abstract, it doesn't look like the researchers of the Turkish study controlled for temperature effects either, but if you have the full paper, please send it to me and I will take a closer look.

I'm not aware of a study on the cancer risk to rats from proximity to a campfire, but I would imagine that there would be some adverse health effects if they exposed the rat internal tissue to similar amounts of thermal radiation. Perhaps more due to the additional factor of smoke inhalation.

And again in the relative risk department, before I considered avoiding a microwave oven, I would also avoid anything baked, fried, or roasted, as these cooking processes produce acrylamide, a known carcinogen. No more coffee for you.
posted by grouse at 1:58 PM on February 5, 2007

Ok, there's an exception -- radiation around the microwave range, like your microwave oven, will cause a warming effect. No big surprise there. If the warming is intense enough, there will be heat damage.

Just to make sure this is clear, you have to be in the microwave for the radiation it produces to affect you. This is because, as knave says, of the Faraday cage. Of the things you could worry about, anything in a Faraday cage is very very low on the list. (If you've ever been to the Boston museum of science, you may have seen this demo -- that Faraday cage in the center has a person in it.)
posted by advil at 2:22 PM on February 5, 2007

Thanks grouse. I read this book by a neurobiologist that states that intense radio and microwaves (such as used in certain professions - she mentions physical therapists) can have a deleterious effect on the baby (she does mention that heating is the most obvious problem with higher levels of radiation) and that while home microwave ovens in the US are safe, it is probably a good idea to stay a few feet away from an older microwave oven when it is in use.

And yes: during a future pregnancy I would make sure to limit my fried potato intake as well (fried potatoes are by far the biggest sources of acrylamides). And I wish I had known about the unhealthful properties of trans fat when I was pregnant. In "my" pregnancy forum, we all laughed about the people who avoided donuts during pregnancy. It was just flour and oil right. What could possibly be wrong with that?

Just to make sure this is clear, you have to be in the microwave for the radiation it produces to affect you.
The rats in the study I quoted were not in the microwave. Microwaves, especially older ones, do sometimes leak.
posted by davar at 4:12 PM on February 5, 2007

If you want to get the laptop a little further away (leaving aside the question of whether you need to worry about this or not), you could put it on a table or desk and plug in a seprate keyboard. If you are actually using it on your lap I'm sure this would need to be changed in a few months at any rate.
posted by yohko at 4:36 PM on February 5, 2007

http://www.hps.org/hpspublications/articles/microwaveoven.html

In reality, ovens are notoriously resistant to leaking microwaves. In the past 10 years, I have only heard of two instances of oven leakage exceeding the FDA/CDRH standard of 5 mW cm–2 at 5 cm. The first oven had a physical puncture of the protective metal grid at the viewing window (caused by an exploding metal food container). The second oven had a defective door seal as a result of dropping the oven off the top of a refrigerator. In addition, I once found an oven that had been intentionally disassembled to remove the magnetron tube and power supply for use in a laboratory experiment (apparently research funds were short). In all of these cases, the oven had been severely damaged either through misuse or abuse.

Actually that whole site might be of interest, especially this part.
posted by advil at 6:42 PM on February 5, 2007

About the microwave leakage: not everybody is in the US. Regulations in other countries may well be less strict. The opinions in this thread seemed to be that there was no way that microwave radiation itself could do any harm, even if there was no door because it is non ionising radiation. The only harm that could be there is from a warming effect. That sounds so comforting, because surely, like 0xFCAF said, we would notice before our pregnant bellies got so hot that there was damage, right? But in fact, according to the neuroscientist book, strong microwave radiation is dangerous for pregnant women.
posted by davar at 2:48 AM on February 6, 2007

But in fact, according to the neuroscientist book, strong microwave radiation is dangerous for pregnant women.

Well, Dr. Eliot can write all sorts of things, but being a neuroscientist generally does not make one an expert in the effects of microwave radiation on biology. But actually she states something much less alarmist than what is reported here somewhat out of context:

Studies with rats, mice, and chicks have shown that intense exposure to radiation in the microwave and radio-frequency range is indeed dangerous during gestation. High-intensity levels can cause fetal death or malformations, especially of the brain and skull. These effects are not suprising, since the esposures also substantially elevate the animals' body temperature. Lower intensities do not cause heating and have generally been found to produce no harmful effects. In any case, the levels of radio- or microwave exposure in these animal experiments are well above those to which most women are normally exposed. [emphasis added]

I'm missing the part where it says to stay away from microwave ovens or refutes the idea that damage is due to heating. Seems like it is just the opposite, actually.

Let's look it the scientific background for this bit of the book. According to page 467 it comes from an article by Bentur on "Ionizing and nonionizing radiation." I believe this is a chapter in a book called Maternal-fetal toxicology, which has a section on microwave ovens which concludes that any known effects are due to heating. In one study, the threshold for damage was estimated to be 41.5 °C (107 °F, a rather nasty fever). The section then states:

Microwave ovens properly handled should be regarded as safe.

The whole chapter concludes:

So far, it has not been proven that exposure to nonionizing radiation (VDT, microwave, ultrasound, etc.) below the maximal permissible level is associated with measurable adverse repoductive outcome. At present, ultrasound not only improves obstetrical care but also reduces the necessity of diagnostic x-ray examinations. Nevertheless, continued surveillance and more studies of potential risks are necessary.

I think it is just a wee bit disingenuous to claim that either Dr. Eliot or the scientists upon whom she relied for her background for this subject would tell you to stay away from a microwave oven.
posted by grouse at 3:43 AM on February 6, 2007

Of course, I should note that davar never made such a claim. Still, using the Eliot book as support for a practice of staying away from a microwave oven is only taking one bit out of the context of a whole paragraph that basically says the opposite.
posted by grouse at 3:50 AM on February 6, 2007

Grouse, in the next page of the one you quoted she actually recommends you stay a few feet away from an older microwave oven. In the same chapter, she says that while most women are not exposed to this kind of radiation, people in certain occupations, like physical therapists, are exposed to higher levels of radiation, and that could have adverse effect on the baby.

I agree that her chapter is somewhat confusing, since she first said that the most obvious problem is the heating effect (I also mentioned this in my first comment about her book, I am really not trying to be disingenuous here), but later does indicate that there may be problems before you notice: "hey, my belly is getting way too hot here".

To make my point again: I think microwave ovens in the US are safe during pregnancy. However, I think that research suggests that that is because they are shielded, not because the radiation in itself is always harmless for unborn babies. For the record: I do agree that the risk is small and that the risk of eating lots of potato chips and donuts is probably higher. I still think some people in this thread are somewhat dismissive of the potential effects of non ionizing radiation that do seem to be there. If do not dispute the effects are due to heating, but they do seem to occur before the pregnant women notice their bellies getting very hot, contrary to what was suggested earlier in this thread.
posted by davar at 4:47 AM on February 6, 2007

in the next page of the one you quoted she actually recommends you stay a few feet away from an older microwave oven

You are right, I totally missed that. However in the very same sentence it repeats again that "microwave ovens are considered safe by pregnant women."

I personally am dismissive of the danger here, not because it does not exist, but because it is minuscule compared with some very real risks. If the same time and energy were expended on, recognizing the risk of automobile collisions maybe we could get somewhere.
posted by grouse at 5:53 AM on February 6, 2007