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Mobile Phone Transmitter Causes Brain Tumours?
Peter writes "Seven staff in the one building have been diagnosed with brain tumours, and everything seems to be pointing to the mobile phone towers located on the roof. The building is owned by RMIT University and an investigation is taking place. Five of the seven staff worked on the top floor of the building. Medical experts contacted by The Age Newspaper said no definitive link had been proved between mobile phone tower radiation and cancer."
I believe that an SAR (specific absorption rate) of 10 Watts per kilogram is the safety limit set by the NRPB. I guess they need to do tests as to whether the people experienced this from the towers. Cell phones have a SAR of about 0.2 on average. As always, Wikipedia provides a great reference to this subject.
My work here is dung.
Certainly a link, but where's the evidence that it's a link to the mobile phone transmitters?
It could equally be down to insufficient ventilation allowing natural Radon to accumulate in the air inside the building.
Of course I would be worried - I would be worried about the building however, not the phone mast. I've just been reading the forums attached to the story and there's a few interesting comments in there - notably this one:
There are shills on slashdot. Apparently, I'm one of them.
Cell site base stations are self contained. The only things that run to them are the mains supply cables, which are indeed beefy, but that's 60Hz, not the UHF that mobile phones run at. The antennas used for cell site base stations also have a decidedly toroidal or sectoral radiation pattern. Every one I've seen in the last 10 years has used a set of sector patch antennas, which have excellent pattern control (energy goes in a set direction with set limits, not anywhere else). It's in the best interests of the cell companies to minimized the radiation that goes straight down in favor of the radiation that goes out, as straight down mostly wastes power that could be used to increase coverage somewhere else.
I don't doubt that there seems to be a link, but whether or not it's causal needs some very carefully done science, not a newspaper story.
This is not a sig. this is a duck. quack.
The problem with the statement 'consistent with radiation' is that the Doctor means ionizing radiation, and a cell tower emits non-ionizing radiation. BIG difference.
http://en.wikipedia.org/wiki/Ionizing_radiation
Welcome to Slashdot, where electrical engineers, or people who think of it as a hobby, will swear backwards and forwards that they know and understand every effect of radiation.
Errr right, maybe I just listen to the expert's opinion.
There are shills on slashdot. Apparently, I'm one of them.
GSM wavelength is not ionizing so it can't be dangerous by itself. But some think the bursts used by GSM protocol create a low frequency envelope that may affect living tissues (that would behave like an AM receiver). There is also the low but measured local thermal effect. Those effects are hard to evaluate but hundred of million people using cellular tend to show they are probably not that dangerous.
On the other hand, the high occurence in this very building compared to the lack of such situation near the large majority of other antennas make me agree with the idea that there is another cause to this particular situation.
The internet seems to agree with me. I'm not trying to be a jerk, rather I'm trying to help spread understanding. I hope this link benefits everybody here.
Taking guns away from the 99% gives the 1% 100% of the power.
How do you know how much radiation is being put out by these towers? I've worked in the industry for quite a while, and can tell you that very few towers, even ones with lots of antennas on them are actually putting out significant amounts of power (where significant = within an couple of orders of magnitude less then you experience when using a cell phone, at distances where the general public is exposed, including floors directly below the transmitters)
Contrary to popular belief, neither the size of the antenna nor the number of antenanas tell you anything about the power output. Big antennas are particularly useful for picking up weak signals, and multiple antenna arrays provide spatial diversity which also improves the reception of weak signals. Think about the Deep Space Network dishes, they are huge, not because the signals are powerful, but the opposite, because they are so weak.
Finally, big antennas are more efficent at directing the energy in a specific direction. Unless they are pointed down at the roof it is very unlikely that there is much energy actually making it into the building.
--- There are two kinds of people, those who accept dogmas and know it, and those who accept dogmas and don't know it
This is incorrect information. I have worked on cell sites and the standard installation procedure, at least regionally, is to have transmission and switching equipment in a cabinet on the ground level and run several antennta cables up the tower to the antennas. On buildings sometimes the equipment cabinet is on the roof, shortening the antenna runs but I have seen a lot of building with installations similar to towers where the antenna runs go all the way from ground level to the roof on the exterior of the building.
>This is totally different; those towers are pumping out huge amounts of >radiation, to try and make sure you can get a strong signal at great >distances. It's not like living inside a nuclear reactor, but its close >enough to be a bad idea.
This is not true. A GSM cell phone puts out maximum 2 W peak (900 MHz band) or 1 W peak (1800 MHz band). The average is 1/8 of this. A base station puts out a few tens of Watts. The power levels cannot be that different since you want a fairly symmetrical link budget.
The antenna elevation pattern of the base station is such that most of it is directed towards the horizon, and less towards the base of the tower. Since the power density (W/m^2) will drop off as the square of the distance, these two factors will cancel in such a way that you essentially get the same power density when moving out from the base station at ground level, at least for several hundred meters.
You will not be nuked from the handset, and certainly not from the base station. The power density from the base station will always be many orders of magnitude below that from the handset...
Since your handset will automatically decrease its power to mW when close to a base station (to save battery time, etc.), the best way to get less exposure is actually to be as close to a base station as possible!
1) Waste heat in the electronic circuitry
2) Lacking air circulation arount your ear
3) heat from your hand
The fact is, the human brain is surprisingly tolerant of radiation exposure. Radiation oncologists take advantage of this characteristic to treat cancers that have metastasized to the brain. Whole-brain external beam radiation therapy uses ionizing radiation, many orders of magnitude more energetic than any cell phone tower, but the occurrence of de novo brain tumors after brain XRT is actually pretty rare.
6
It's a coincidence, not a link. We don't have nearly enough information to call it a link, let alone a causal link. For example, were the tumors all of the same variety? What's the family history of these folks regarding cancer? Are there other known cancer risks in the environment where these people work? For that matter is there any reason to think that cell phone radiation would selectively affect brain tissue differently than other tissue in the body? In the case of cell phones, proximity of the radiation source is thought to be a potential issue. In the case of a cell phone tower, these people were not holding it next to their heads. They would have been having whole body exposure, and if cell tower radiation was the cause one would expect an increase in all cancers (especially leukemias).
Almost one out of two people will develop cancer. When we realize that fact, then clusters of cancers seem less amazing. For some reason, people think that cancer is a rare disease, but cancer is extremely common. Of course "it" is a set of diseases, some of which are fairly common (prostate cancer, breast cancer, skin cancers, leukemia, lymphomas, etc.) and some which are rare. Brain tumors are not all that rare, including the tumor that public sentiment tends to think is linked to cell phones (acoustic neuroma).
In one of my Criminology classes we talked about the use and misuse of statistics. The example was used that areas with a high stork population have a high human birthrate. Does that mean that storks bring babies?
Like the post above said:
Correlation is not causation.
500 dollar reward for tip(s) leading to the arrest of the person(s) who stole my sig.
But if it *is* built like this, it is absolutely impossible that any radiation of any kind managed to get through that roof to the people below.
g /6d422cb367cac613, not a Faraday cage.
A sheet metal roof like that is a ground plane http://groups.google.com/group/sci.electronics/ms
I'd also say you're wrong on empirical evidence: cell phones generally do work inside buildings, this one is no exception.
Blank until
Although I agree with the essence of your analysis, you might want to consider:
- a GSM basestation would be potentially transmitting in all 8 timeslots hence the average power would be 8 times higher than a handset;
- GSM/PCN basestation trasmitter powers are quite often about 25W (although I'm not sure whether this is the power after combiners/feeder losses).