23

Note that I'm not asking about high energy RADAR and telecommunications installations or similar systems which can cook small animals alive.

I've heard lots of stories about negative health effects of electromagnetic radiation generated by electrical generation, transmission and distribution systems, such as increased risk of cancer and leukemia for people living near electrical substations and power plants.

I'm personally not a fan of the theory, but I've seen some research results which could be interpreted both ways, so this looked like a nice question for this site.

  • 2
    Could you provide links to the research results you mention, please? – Nthaoe Mar 15 '11 at 7:23
  • 2
    I want to hear more about this "cooking small animals" bit... – Shog9 Mar 31 '11 at 2:33
  • @Shog9♦ That point is actually very interesting. I heard of cases where airplane ground search radars could kill rabbits and I've heard of dead birds collecting near high power transmitters. After doing some research, I couldn't find any concrete information on the Internet. I do however have some sources that do make the idea plausible: RF danger signs, RF burns, RF burns on wikipedia. – AndrejaKo Mar 31 '11 at 9:27
  • There's also some "colloquial" evidence of RF burns, for example here. Maybe the first paragraph of my question should be a question itself? Also, there are some reports form IEEE magazines on that, but I don't have access to them. – AndrejaKo Mar 31 '11 at 9:29
  • 4
    I love the fact that the same people who make this claim also commonly believe that putting magnets in their shoes is therapeutic. Apparently they don't get the whole electricity/magnetism connection. – JohnFx Jun 4 '11 at 20:31
21

Quackwatch has a great article on this subject, which gives reasons to not believe power lines are health hazards:

  1. The fields produced by power lines are very small. Power lines produce both electric and magnetic fields. The electric field is greatly reduced in magnitude within the human body, because the body is an electrical conductor. In fact, power lines produce electric fields inside the human body that are much smaller than the electric fields that normally exist in the body. The magnetic field is not significantly shielded inside the human body, so the only realistic possibility of health effects come from the magnetic field. The magnetic fields from power lines are rather small. Typically they are about 2 milliGauss. By comparison, the earth's field is typically 300-500 milliGauss, with the exact value depending on the location on the surface of the earth. Magnetic fields from power lines are therefore hundreds of times smaller than the magnetic field from the earth. If the relatively weak magnetic fields from power lines had significant adverse health effects, you would expect the much stronger magnetic field from earth to be devastating. Yet no such effect has ever been found. In experiments on animals, mice have lived for several generations in 60 Hz magnetic fields as high as 10,000 milliGauss, thousands of times higher typical power line fields, without any adverse effects.

    It is well known that fluctuating magnetic fields give rise to an electric field by the Faraday effect in physics. Yale physics professor Robert Adair demonstrated that these electric fields are very small in comparison with the naturally occurring electric fields arising from thermal fluctuations [12]. This is a good benchmark to indicate that the powerline magnetic fields can't be important.

  2. No plausible mechanism for adverse health effects has been postulated. It is well known that electromagnetic fields at high frequencies (e.g., ultraviolet light) can have adverse biological effects. This is why sunlight is a good disinfectant: it kills bacteria. However, the frequency of power line fields (60 cycles per second, or 60 Hz) is too low to have this effect by many orders of magnitude.

  3. The initial study was flawed. Wertheimer and Leeper did not actually measure magnetic fields from power lines. Instead, they classified the homes according to their wiring code. The wiring code was then used as a surrogate for the powerline magnetic field, which was unmeasured and unknown. This is a flaw in the study. Later studies actually measured the magnetic fields from power lines and found no consistent relationship between measured magnetic field and incidence of cancer [13]. It is important to realize that there are important possible confounding factors in such epidemiologic studies. For example, one possible confounding factor is an income effect. Living right under electric power lines is not a desired residence, and often is a low-income housing location. People living near power lines tend to be poorer than the control group, and there is a strong and well-known epidemiological relationship between poverty and cancer. Gurney and others showed that the homes with the presumably higher-current wiring code tended to be lower income [14]. Thus the original Wertheimer-Leeper study was biased. In addition, it was based on relatively few cases, and the statistics were consequently rather poor.

    Later epidemiologic studies were properly designed, and some were much larger in scale. For example, the government of Finland performed a huge study of 134,800 children, with one million person-years of exposure. There were 140 cancers in the group, 5 fewer than would be expected by chance [15].

    Consequently, the epidemiologic studies, taken as a whole, consist of a few early low-quality studies, some of which yielded positive effects, and later, higher-quality studies, which yielded negative studies. If power lines really caused cancer, it is natural to expect the later studies to confirm the earlier studies. Instead, this has all the earmarks of a nonexistent effect.

  4. The incidence of leukemia has been decreasing. During the last few decades, the use of electric power and electric appliances has increased the 60 Hz powerline magnetic fields to which we Americans are exposed by roughly a factor of twenty. If power line fields were a significant cause of leukemia, there should have been a dramatic rise in leukemia. Leukemia rates, however, have slowly decreased. As noted by the physicist J.D. Jackson, this argues against any significant causal relationship [16].

  • 2
    "The magnetic fields from power lines are rather small. Typically they are about 2 milliGauss." At what distance? – Fattie Apr 13 '14 at 16:47
  • @Fattie The best resource I could find is eskom.co.za/OurCompany/SustainableDevelopment/… It suggests that the range is about 70-400 mG on the ground level, depending on the current. For the highest-current lines, this can rarely be more than the background magnetic field. However, this is only for the simplest designs - magnetic fields from multiple wires interact. In a well balanced system, even high-current lines are around 60 mG at ground. – Luaan Jun 11 '18 at 6:22
  • @Fattie Doing a bit of back-of-the-envelope calculation, the 2 mG mentioned in the answer would correspond to about 10-50 m horizontal distance from the tower, depending on tower design and current. Though note that 2 mG might be an average or some typical value - there's a lot more low-current wires than those "backbone" monsters, and the lines close to human habitation are usually low-current. – Luaan Jun 11 '18 at 6:25
  • Reason #2 is complete BS (even if the overall claim is correct). A 60 Hz power line simply switches direction 120 times per second. The actual photons released most certainly are not only 60 Hz. Now, they're still too weak to act as ionizing radiation, but still... – forest Nov 15 '18 at 9:52
4

This recent EU-sponsored study on the epidemiological effects of exposure to electromagnetic fields suggests that there is a causal link between exposure to electromagnetic radiation from power lines and childhood leukemia (and possibly also Alzheimer's disease) for electromagnetic flux density exceeding 100 micro teslas. Taking that average high tension power distribution lines are running around 400kV, the flux density can easily exceed that threshold within a few hundred meters radius. The study found no association with other types of cancer or cardiovascular disease. There are also well known links between EMF exposure and migraines/headaches, dizziness, and depression (also cited within the EU study on page 27).

  • 4
    a) The linked article is NOT a study, it is a review. b) The review does NOT suggest a causal link between exposure from power lines and childhood leukemia, it merely shows some tentative, badly replicated, low-n hints of such a possibility, however there is not clear body of evidence. c) 100 micro tesla is a lot and you will not get that from any kind of power line, if you're even 5 meters away. d) the average kV of high tension power lines is not 400kV, I don't know where you got this number but the most frequently used powerlines operate with 110kV, followed by 220kV lines. – markus May 23 '13 at 12:25
  • f) Where is the source for your migraine claim? The EU review does not make any such claims for power lines. – markus May 23 '13 at 12:26
  • @markus: You are correct that the review does not make any claims for power lines, which is why I qualified the statement in relation to EMF exposure. See the first full paragraph of page 27. – ESultanik May 23 '13 at 14:39
2

Bit of a devil's advocate one here.

There has been some research on grounding the human body, and the associated health benefits:

To throw some numbers out:

The method to effectively ground people while in bed was developed and the study began. The effort produced, with a control group, the following results:

85% went to sleep quicker

93% reported sleeping better throughout the night

100% reported waking, being and feeling more rested

82% experienced a significant reduction in muscle stiffness

74% experienced the elimination of/or a reduction of chronic back and joint pain

78% reported improved general health

Now if this research into grounding is correct and the human body can store up charge then it is quite plausible that electromagnetic radiation could increase the charge levels in our bodies.

If you couple this with the reports that being grounding help wounds heal quicker you could say that it does have a negative affect on our body because it reduces our bodies ability to heal itself effectivly.

Another link to research in this area:

  • 4
    If you are going to downvote you could at least comment to explain why... – Ardesco Apr 18 '11 at 15:35
  • 2
    Not the downvoter, but to me the paper looks bogus. First I'll focus on things I'm familiar with. Let's take a look at the AC voltmeter part. They just mention AC voltmeter and say nothing about it. To me, that's enough to invalidate any readings they got. They didn't mention if the voltmeter expected a sine signal or if it was "true RMS" voltmeter of if it was one of those voltmeters which show the actual voltage including the DC offset. Next, they didn't mention its count number and measurement uncertainty. They didn't provide any specifics of the "earth ground". cont. – AndrejaKo Apr 18 '11 at 16:28
  • From my practical experience, the "earth ground" is itself extremely important in cases where exact measurements are needed. If for example building ground was used, than a device dumping current to ground can affect reading. Also, there can be voltage between different ground points in same room! Another important fact is the connection of the ground circuit. Is it connected to ground at the building site itself or somewhere else. In case they used their own ground probes, how did they connect them to the ground? What was the weather at the time? – AndrejaKo Apr 18 '11 at 16:33
  • 1
    Next, even if there is voltage between ground and a person, we need specific part of the body where measurement was takes. It's normal to have potential difference between different body parts, so connection point itself is important. Now let's move to the ground mat part. They said that they "protected" the test subjects with a 1/100 A fast fuse. That itself is very dangerous. Proper way to connect ground mats/straps/bracelets and so on is using a high resistance resistor. This way, even in case of large amounts of excess charge, person can be safely grounded. – AndrejaKo Apr 18 '11 at 16:39
  • With use of a fuse, the fuse will hopefully blow fast enough to prevent any serious injury in case of large amounts of excess charge. This leads me to question competency of the author. Furthermore they focus more on the fact the the ground rod is near the window than on the way the rod is actually connected to the ground. Another interesting point is that the pads were under the sheets. Unless they used special conductive sheets (and they didn't mention that they did), efficiency of such setup is questionable. – AndrejaKo Apr 18 '11 at 16:42

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .