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Killer Apartment Vs. Persistent Microwave Exposure?
An anonymous reader writes "I am considering buying a penthouse apartment in Manhattan that happens to be about twenty feet away from a pair of panel antennas belonging to a major cellular carrier. The antennas are on roughly the same plane as the apartment and point in its direction. I have sifted through a lot of information online about cell towers, most of which suggest that the radiation they emit is low-level and benign. Most of this information, however, seems to concern ground-level exposure at non-regular intervals. My question to Slashdot is: should the prospect of persistent exposure to microwave radiation from this pair of antennas sitting twenty feet from where I rest my head worry me? Am I just being a jackass? Can I, perhaps, line the walls of the place with a tight metal mesh and thereby deflect the radiation? My background is in computer engineering — I am not particularly knowledgeable about the physics of devices such as these. Please help me make an enlightened decision."
Dont buy it. You will worry yourself sick whatever we say.
Tin foil suit.
Be you Admins? nay, we are but lusers!
If you're that close, you should be able to put a small coil of wire in your apartment and induce a nice free electric current. It won't make you popular with the owners of the antenna but what do they know? Otherwise no, I don't see a problem with RF.
Tubby or not tubby. Fat is the question
I wouldn't risk living there.
As far as I know (and I'm no expert, just good at googling) , the radiation levels from antennas are relatively safe about 3-5 meters away from them but depending on the type of antenna their beam can kind of focused in one direction so that 3-5 meters estimation could mean a measurement ouside the beam direction and if the apartment is inside the beam the radiation could be above safe levels. For example, I've heard that in my country, if you live on the last floor of a building and an antenna is above, the antenna must be on a pole at least 2-2.5 meters high so that distance between the apartments below and the emitter is around 3 meters.
Cellphone antennas would not be uni-directional so there shouldn't be any focused beam or whatever it's called but who knows what other antennas will be installed in the future on the same pole.
So from a radiation point of view you may be safe, but you never know how sensitive you are or how sensitive your family / children etc will be.
Second, while you may not care so much, the property will be harder to sell in the future because of that antenna.
1) Buy it. ...
2) Sue phone company
3)
4) profit!!!!!!!
At the bottom of the
The FCC enforces on a case-by-case basis. Unless someone has turned this situation (this SPECIFIC apartment being this close to a transmitting antenna) to the FCC, then chances are that they have no idea the situation even exists. As for my $0.02, you don't want to spend any more time than you have to being 20 feet from a transmitting antenna, LET ALONE living next to one.
There is a product called Scotch-Tint that is a EMF reducer for windows. Combine that with some metallic fabrics on the walls on that side. www.lessemf.com is one of many suppliers for those products. I've used a conductive plastic from those folks to make a shielded rack for some RF sensitive equipment.
Even if you get some information from /. and you buy it, you will need to explain that it's safe to every visitor who notices these antennas.
The facts about urban wireless towers is that they're very low power because of the high population density. They use very small cells in urban towers to achieve a very small coverage radius so that they can put up more towers in the city and reuse the same spectrum. Furthermore, just being in-doors cuts the power level 10-fold and I'd really doubt that you're getting more than -40 dBm which is equivalent to 100 nanowatts of power even if you're outside the windows. My Wi-Fi Access Point is 5 feet from me and it's got a power level of -13 dBm which is about 1000 times stronger than a -40 dBm signal. Now if you think that's high, your cell phone probably has a signal strength of +10 dBm which means the power density is 100,000 times stronger than a -40 dBm signal. And if you think the phone is dangerous, check out this article from me http://www.digitalsociety.org/2009/09/sar-ratings-are-not-a-measure-of-radiation/ and this article http://www.digitalsociety.org/2010/01/cell-phone-exposure-prevents-or-reverses-alzheimer-in-mice/. So really, worrying about that cellular tower is just silly. If you're really worried about it, buy one of those $100 "Electrosmog" meters and measure the signal strength yourself at various places.
Mobile company raised cell tower next to some village. Locals complained about health problems caused by this tower. When contacted cell company CEO replied:
- That's nothing. Wait and see what happens when we turn it on.
Ask the landlord to relocate the cell-phone towers.
This strategy is quite effective in dealing with obstinate landlords. I should know since I'm serving time for 1 count of voluntary manslaughter.
Every time you do you are holding the antenna of that right next to your head. Yes it's lower power, but there's an inverse square distance law at work to, so the intensity is massively greater than that from the one 20 feet away. So either buy the apartment, or stop using cell phones. They are the only two logical choices.
Are there any laws against passive shielding inside your flat? After all, you could simply put standard metal office furniture inside your flat, and that would cause massive interference, too. I'd say, if the phone company doesn't want the signal to be blocked by whatever is inside a flat, it should put the tower somewhere where it won't be blocked by something inside a flat.
The Tao of math: The numbers you can count are not the real numbers.
I work with high power RF for a living. There are a lot of variables that contribute to non-ionizing radiation. Proximity, transmitter power, antenna radiation pattern, materials between you and the antenna, etc. There are ways to estimate the field intensity, but unless you know all the necessary factors, your calculations could be off by orders of magnitude. Having said that, the poster who commented that urban cells are lower power is generally correct, however, in a major metropolitan area, the cell can have many channels active at once, and the effect is cumulative. ANSI C95.2 is the safety standard covering this radiation. It's pretty technical, but the gist is the licensee (in this case the carrier) is responsible for making sure they don't cook the public.
The carrier must certify to the FCC that there are no publicly accessible areas that receive unsafe RF fields. The exact number varies by frequency, but generally there are two levels specified, one for publicly accessible areas and another for areas where personnel who have been trained in RF can work in levels above the public ones. These areas are normally calculated by the carrier prior to installation and they won't install if there's any chance they might exceed the safe levels.
As an example, I did an RF survey at one location where there was a multiple-transmitter FM antenna installed on top of a building that was across the street from another taller building. We had three FM broadcast transmitters operating on this antenna with about 250 kilowatts of radiated power, and the measured levels in the building across the street were not over the limits for public access. This was about 150 feet horizontally from the antenna. The solar coating on the building's glass stopped enough RF that it wasn't a problem.
If you want to measure it yourself, there are some inexpensive meters that are pretty accurate that will give you an indication of how much RF you're seeing. The one I have is this one: http://www.trifield.com/TrifieldMeter.htm It's about $150. I've seen these for sale at Fry's.
I have calibrated mine against a $5000 Narda commercial RF radiation meter and it's pretty close, certainly close enough for a "go/no-go" test which is what I use it for.
----- Leghorn "Not responsible for program content"
And then fail utterly to find a controlled study that shows repeatable results.
Lets make this clear, in over fifty years of trying nobody and I repeat nobody has yet managed to do a REPEATABLE study that shows harmful effects of low level non-ionizing radiation.
The key factor here is REPEATABLE. If it cannot be repeated it is just a meaningless statistical fluke.
Normally I wouldn't worry at all.
But the fact that,
1) It's only 20 feet away,
2) It's in the same plane as you, and,
3) It's pointed AT you...
That worries me some more. Obviously you want to talk to someone who really knows this stuff, and can also measure the EM radiation in your future apt.
I also assume its a 'killer' apt because its in a great location and its CHEAP. And of course, its CHEAP because everyone is scared of the antenna pointing right at it...
You can tell how powerful someone is by the magnitude of the crime they can commit and be able to get away with.
If exposure to asbestos was of any danger to the public health,[sic] there is no way you would be seeing asbestos anywhere near apartment complexes.
If your microwave popcorn starts to pop before you turn the microwave on, it's probably not safe.
Beta sux! Join the Slashcott! http://hardware.slashdot.org/comments.pl?sid=4760465&cid=46173047
You are probably right, because it would need a conspiracy to hide research results. But... remember the tobacco companies' bought research.
A while ago, I learned a new expression which I've never seen in my native Swedish media -- which do say something about at least Sweden's political trustworthiness:
Karma: Excellent (My Karma? I wish...:-( )
800+ watts in the 2.4ghz band is a known killer.
Most consumer devices run at under 5 watts.
Amateur radio operators have been using devices that can put out 5 to 1500 watts since the 1930s (possibly earlier)
Is that why it has been observed that children living under power lines had a 70% increased risk of leukemia?? Is that why DDT has been sprayed directly onto people as a standard anti-mosquito practice?. Is that why asbestos has been used extensively as an insulator and structural material? Is that why lead paint has been the standard paint for home renovation and art? Is that why gasoline is carcinogenic? Is that why wet Portland cement causes serious health problems which include severe burns that damage nerves?
Just because something is banal, widely used and is seen as an accepted practice it doesn't mean that it is perfectly safe and free from any nasty side effects. History has a pretty long damning list of cases where the dangers are only known after the stuff that causes them is widely deployed.
Slashdot, fix your code or at least hire someone who is competent at it to do it for you.
The studies that found a higher risk of leukemia in children didn't control for family income or any other social factors. It was correlation which isn't particularly useful
Is that why it has been observed that children living under power lines had a 70% increased risk of leukemia?
http://www.quackwatch.org/01QuackeryRelatedTopics/emf.html
Is that why DDT has been sprayed directly onto people as a standard anti-mosquito practice?
http://en.wikipedia.org/wiki/Malaria
History has a pretty long damning list of cases where the dangers are only known after the stuff that causes them is widely deployed.
So your solution is .... avoid everything? How much does it cost to live in a clean-room, anyway?
Just out of curiosity, I gotta ask ... why do you hate science?
Wait a minute, you can afford a penthouse apt in manhattan, but you are unsure about the safety of living next to a cellular antenna array that (to use your words) is pointed right at your apartment, so you turn to Slashdot? I don't believe it.
I also don't believe that any company would install a cellular antenna array and point it at a structure - it would seriously impact the coverage area of the antenna, and they could probably just as easily installed the antenna on a taller building and avoid interference...
Ken
Malaria is rather more dangerous than DDT. DDT was banned by a politician, who was overriding the decision of his own regulators who had actually heard and read all the evidence and concluded that the benefits of DDT outweighed the risks that alarmists trumped up.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
You are assuming that any other potential buyers even notice the cell towers. I garauntee about 90% of them see that they have full bars on their phone and think no further of it.
-Steve
"I opened my eyes, and everything went dark again"
Amateur radio operators have been using devices that can put out 5 to 1500 watts since the 1930s (possibly earlier)
Yeah, and look at what all that radiation has done to them. It's turned them into hams.
"while democracy seeks equality in liberty, socialism seeks equality in restraint and servitude." de Tocqueville
Unless you are intercepting the entire beam of a directional antenna (only likely if this is an antenna communicating with another mast or base station, rather than the more likely scenario of one designed to talk to handsets) then inverse square is the correct formula, surely.
The FCC may have something to say about that though. If he is close enough, his mesh may block enough of the signal to put the antenna out of use.
Any passive blocking that he puts on the walls or windows as an owner is something that he can't he held liable for(as opposed to active blocking or putting up a billboard or similar). I'd love to see the judge's face when the cell phone company tries to explain how their antenna requires his apartment to be non-shielded to operate properly(ie - we need to beam the signal *through* it because we put it in a bad location). They are supposed to be placed in such a manner that they are clear of buildings and physical obstructions. Hence the reason they are almost always on a small tower above a roof top. One thing, though - if you shield your place from these frequencies, you won't be able to use your cell phone at all while at home. You *can* turn your house into a giant Faraday cage. But expect it to act like one as well. You likely also won't be able to use your radio or HDTV over the air. Nothing comes in means nothing gets out as well. (OTOH, Wi-fi in home would be secure - heh)
Also, the refit won't be cheap. That Scotchtint runs about $1000 for a 60"x100ft roll. EMI resistant mesh for the walls generally runs the same. Generally you have to re-plaster or put another thin layer of drywall over top of it, which is factored into that price. And of course, it has to be installed properly. At that range(feet vs hundreds of feet) it will generate a significant amount of current.
Possible? Of course. But in today's world, being without tv, radio, wireless, and so on in such a place in NYC would be horrendous. In fact, trying to sell a place that you purposely turned into that would probably make it just as hard to resell as if you did nothing at all. I'd just keep looking. Maybe there's a similar place a block or two over?
Actually we made it against the law to remove/prevent building of cell-phone antennae based on medical arguments. Thank Congress.
When using directional antennae with 2.4 GHz Wifi, you're limited to tens of milliwatts or even less, depending on the gain.
Last time I checked Ham's are authorized 1500 watts @2.4Ghz. They just need to conduct the safety evaluation. Now meeting the safety requirements with a 24dbi dish might prove difficult... But if you can, you're good to go. (yes, I'm serious, think morse code via moon bounce...)
It's a buyer's market for luxury property in Manhattan right now. Express your concerns to the sellers and hint that you'll need to have a survey team out to test for EMF exposure before you'd consider buying. Build an image in their minds of 3-4 guys in Tyvek jumpsuits walking around with meters on the roof and in the halls and knocking on your future neighbor's doors. (There's no reason for them to wear Tyvek jumpsuits, but you get the idea.) They'll likely offer to drop the price in exchange for you not doing that. More than enough to cover the cost of shielding and chemotherapy.
Prisencolinensinainciusol. Ol Rait!
If anyone is interested, here is a summary of the study in a presentation form (PDF):
COFAM study result http://www.who.int/peh-emf/meetings/archive/en/vanrongen_tno.pdf
8 of 13 people found this answer helpful. Did you?
Also, recall that the power density drops by the square of the distance from the antenna. So, if you measure the power at one micron away from the antenna, it will be twice the strength you'd get if you measure it two microns away. Extend this out, and at 3 microns, you're down to 1/8th the power, 4 microns = 1/16th. At 20 feet, you should be all the way down to 1 / 3,716,121,600,000th the original power, or about one three-trillionth the original power. Right? So nothing to worry about.
No, you are not being a jackass. It is far better to ask questions and be INFORMED than make assumptions that might not be true.
As an Extra class amateur radio operator licensee I can tell you that the FCC considers exposure to RF radiation a significant risk. To obtain an amateur radio license and to be granted greater privileges, tests are given and several questions pertain to safe exposure limits. While I would doubt that the antenna poses a hazard, for your own peace of mind there is some homework you must do, questions you must ask of the company that owns the antenna and possibly the FCC.
Is the antenna used for receiving, transmitting or both? Is the antenna directional? What kind of gain does the antenna exhibit? What does the energy distribution look like? Are you able to see a site evaluation? (the FCC might have that on record) Find out the name of the company that owns the antenna and ask these question.
Many systems use separate antennas for receiving and transmitting. Doing so allows the antenna to be optimized for the job. It is quite possible that the antenna in question is used purely for reception of the cell signals from another tower. In that case the antenna poses no risk what so ever.
If the antenna is used for transmission of microwave signals a whole new can of worms is opened and RF exposure must be considered. RF radiation exposure limits are divided into two categories, a controlled environment and an uncontrolled environment. Basically, these two categories refer to the exposure limits of people working with the equipment and the general public. Several things are considered when looking at RF exposure limits; antenna type, power delivered to the antenna and the effective power radiated. A highly directional antenna can direct the input wattage into a very narrow beam called a lobe, effectively amplifying the signal in that direction. So a signal of 200 watts can effectively become a signal of much higher strength depending upon the gain of the antenna. One of the advantages of this is that the signal to the sides of the main lobe is extremely weak. From a safety stand point, only something directly in the path of the lobe is being exposed to radiation.
Again, ask the questions I gave to you earlier of an electrical engineer working at the company owing the antenna. Make an appointment to meet at the site of the apartment. The FCC requires they keep detailed information available on their systems just for answering this type of issue.
Regards,
W2TKW
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The FCC enforces on a case-by-case basis. Unless someone has turned this situation (this SPECIFIC apartment being this close to a transmitting antenna) to the FCC, then chances are that they have no idea the situation even exists.
Most urabn cell phone towers have a 20W average power (100W in rural areas), since they want a large coverage area the gain will only be 3dB (parabolic dish 25 dB gain) at 6 meters with a 100W power source and 25dB of gain the power density is 6.7718 mW/cm2 using typical numbers 20W 3dB 6 meters the power density is 0.0086 mW/cm2 the "safe exposure level" for 2.4 GHz as defined by national association for amerature radio is 30 mW/cm2 for uncontrolled and 100 mW/cm2 for controlled. A cell phone with 3W 2.2dB of gain (diapole) at 1 inch would have a power density of 61.4108 mW/cm2.
Knowledge = Power
P= W/t
t=Money
Money = Work/Knowledge so the less you know the more you make
I am a PE and have done hundreds of RF emissions studies on wireless facilities, including rooftop installations like the one you describe. My initial thought is that twenty feet would be an unusually small distance between the antennas and your window. It may very well be much larger then that (50' or more is more likely - and would have much lower emission levels) but seems closer due to the perspective of the surrounding panoramic view. If it were truly only 20', and the building hosted antenna arrays from many wireless carriers (and FM transmitters), then there is a very slight possibility that the levels in your apartment could be near the public exposure limit. This situation is quite unlikely however. Most wireless carriers have an independent RF emissions study performed on rooftop installations that include measurements of the pre-existing antennas, so if you reached the right person and were persuasive enough you might be able to get them to share that with you (very unlikely). Another poster recommended a cheap meter. I'm not convinced of their accuracy, but you could give it a try if it worries you. Someone else mentioned low-E glass and correctly stated that it blocks a significant amount of RF energy. If you have low-e glass then even 20' away would mean your apartment is below the public exposure limit.
--- There are two kinds of people, those who accept dogmas and know it, and those who accept dogmas and don't know it
If DDT were still in use, the Bald Eagle would be extinct, along with several other birds.
...
$7.95/mo, 200 GB disk, 2TBxfer, MySQL, PHP, RoR.
You are confused, total ham bandwidth is miniscule. The entity with the properties you describe is the U.S. military.
Yeah, it's not worth it to save those kids from malaria, at the expense of the Bald Eagle... in Africa... where bald eagles are...
You're obviously talking about two different instances of banning DDT... but it's worth noting that the GP is full of shit and DDT is still used actively to combat malaria. http://en.wikipedia.org/wiki/DDT#DDT_use_against_malaria
That's because those arguments are utter crap. Just like there was an article on /. not long ago (too lazy to search for it) about a transmission tower in Africa where a group of crackpots were saying they were allergic to its signals; however, they found out later that it had been turned off for weeks during a period they supposedly had 'symptoms'.
It's non-ionizing radiation. It doesn't impart enough energy to have harmful effects.
So yeah, thank you, Congress. At least you get things right occasionally.
I support the Slashcott and will not be reading or commenting from 2/10/14 to 2/17/14. Beta is steaming pile of dog shit
The man who discovered aluminum in 1808, a British chemist named Humphrey Davy, first named it "alumium." When he published in 1812 he had renamed it to "aluminum," which is the name still used in America. So where did that extra "i" come from? Wikipedia has the answer.
'An anonymous contributor to the Quarterly Review, a British political-literary journal, in a review of Davy's book, objected to aluminum and proposed the name aluminium, "for so we shall take the liberty of writing the word, in preference to aluminum, which has a less classical sound."'
That's right. All of the haughtiness with which the British defend their extra syllable, all of the bloodshed spilled over the difference, and all of the mutual incomprehension that ensued is due to a change made against the discoverer's wishes based on the rant of an Anonymous Coward. If that isn't a successful troll I don't know what is.
Your brain is not a computer.
Actually, being non-ionizing doesn't mean that it doesn't impart enough energy to have harmful effects. There are other harmful effects beyond having chemical bonds ruptured by EM fields. If the size of your body is near to or larger than a wavelength, your body will absorb some of the incident radiation. It heats your body. This is why microwave ovens have door interlocks. This is why people have DIED, cooked alive while working on microwave communication antennas.
My understanding is that cellphone systems aren't high power; you're likely to be safe. If you're really concerned, buy (about $300), rent, or borrow a field strength meter and find out.
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