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RF radiation level concerns

Hi all,

I am starting this thread so that we can discuss about the radiation levels of a connected home and possible health risks.
In my house for example there are two routers, ST Hub, Philips Hue Hub, Netgear Arlo Hub, two WiFi IP cameras, a DECT phone (EcoPlus), 12 Smartsense door senosrs, 2 Smartsense motion sensors, one z-wave indoor siren and one z-wave smoke detector.

Of these, the routers and the hub and things are considered absolutely essential.

I know the Zigbee devices emmit very low power (1 mW?) and are most of the time sleeping (power cycle 1% or smth) but i am still rather worried about being surrounded by stuff that emmits RF.

Add to the equation an infant of about 3,5 months and you get the picture.

What are your thoughts about the RF radiation levels of my house? Would it be a good idea to call a professional and ask him to measure? Should i rent the equipment and do it myself? Are there any documents about Zigbee power level and cycle?

Please let us try to keep this thread clean and focused. I know there are tens of routers close by. I know that there are other more important factors that contribute to health risks.

Thanks a lot in advance.

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Maybe I am just not aware of the danger implied, so feel free to reference appropriate documentation.

In San Francisco they have installed dozens (hundreds?) of “cellular extension” mini-towers, all at just above 2nd story level. One is 2 houses away from me, the other is about 5.

These are needed due to the hilly terrain of San Francisco, and I presume each one has their power level optimized to serve only the “low signal” trouble spot … but as a citizen, I am rather upset that the feedback process for these is so ineffective.

I believe the RF from external sources is much more of a concern than home ZigBee and Z-Wave.

I met some guys from Switzerland a few months ago, however, who said that in the EU, people tend to be much more concerned about RF radiation and thus they were developing secure and robust power-line control models (i.e., X10 or Insteon “on steroids”). If RF becomes a concern, quite a large number of devices in the home could be served by new in-home Power-Line transmission technologies – if they are demanded by Consumers.

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RF radiation might present a health risk in two ways:

  1. Thermal effect - emitted energy is absorbed by living tissue and the tissue’s temperature increases.
  2. Bilogical effect - RF frequencies may interact with living cells in a way that imposes health risks.

@tgauchat I am resided in EU, as well. Unfortunately living in a rather old house prohibits properly wiring it without bringing it down first…

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From a risk management standpoint, I always try to tackle the largest problems first… i.e., as I mentioned, the micro-cell towers at bedroom level on every block of my neighborhood. But, then again, there’s nothing I can do about those.

For ZigBee and Z-Wave, I don’t know the exact transmit power, but I think they are self-adapting. In other words, if you have a good “mesh”, then nearly all mains-powered (non-battery) devices act as repeaters, and therefore minimizes the transmission intensity, since each only needs to reach it’s neighbors, not the whole home.

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One of the wonderful things about being human if that we are all a little different. If you think you have Electromagnetic hypersensitivity there are ways to mitigate it by removing tech from your life. Some have to go to the extreme of moving to rural areas of the country, using RF blocking paint and living amish to get relief.

Keep in mind that the amount of radiation you receive from wifi, zwave, zigbee are nothing compared to the radiation you receive in the AM/FM, Over air TV and cellular spectrums.

@tgauchat the RF blocking paint might be right up your alley to combat those micro cell towers or neighbours WIFI in SF.



http://www.weepinitiative.org/livingwithEHS.html

From the Wikipedia link:

“The majority of provocation trials to date have found that self-described sufferers of electromagnetic hypersensitivity are unable to distinguish between exposure and non-exposure to electromagnetic fields,[3][4] and it is not recognized as a medical condition by the medical or scientific communities. Since a systematic review in 2005 showing no convincing scientific evidence for its being caused by electromagnetic fields,[3] several double-blind experiments have been published, each of which has suggested that people who report electromagnetic hypersensitivity are unable to detect the presence of electromagnetic fields and are as likely to report ill health following a sham exposure as they are following exposure to genuine electromagnetic fields, suggesting the cause to be the nocebo effect.[5][6][7]”

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There is a lot of misinformation and hysteria surrounding this subject. I think the best thing for anyone concerned is to be an informed consumer, and asking questions like this on a public forum are a good first step. The FCC OET (Office of Engineering & Technology) has several excellent publications on the topic, with specific measurement criteria and guidelines for sale and operation in the United States. It’s mostly “deep geek” engineering stuff, but I’ll point out some exceptions here for anyone interested.

  1. OET Bulletin 56 - This is a good primer for anyone interested or concerned about rf exposure risk.

  2. OET Bulletin 65 - This is dry reading, but table 1 (pg-16) should be of general interest. It covers the entire frequency spectrum, with the exception of VLF and the commercial Broadcast band, both of which have very stringent emission requirements of their own, both in the U.S. and worldwide. Table 1 charts the maximum power to the antenna by frequency band, below which there is deemed to be no public safety risk (and believe me, as someone who has worked in the industry, these numbers are conservative and err on the side of safety). Note that throughout the frequency spectrum, the power level that must be exceeded to even be subject to measurement scrutiny is in the range of 50-500 watts. By comparison, our Zigbee and Z-wave devices operate in the single digit milliwatt (mw) range (1mw = .001 watt), and Wifi is limited to 1 watt max. The stated limits do not automatically indicate a hazard if exceeded; only that exposure measurement is required to determine IF there is risk to public health & safety. Also remember that the guidelines were established based on average antenna gain. The small wire stub or PCB trace antennas used by our HA devices are negative gain (i.e., less than “one”), so any risk is further mitigated.

If you haven’t already figured, my opinion is that there is no risk. The power levels and duty cycle are just too low, even when the power of all devices within our homes are aggregated. As for the suggestion of power line transmission, that’s a non-starter.It (BPL) has been proven to cause more incidental radiation that the intentional radiation it attempts to prevent. Local loop powerline distribution (i.e., within a single building) is viable, but somewhat limited compared to available wireless solutions (Ref. HomePlug Alliance).

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Thank you for your reply. The links are very educating.

This whole Electromagnetic Hypersensitivity situation reminds of that story where a cell phone tower was installed next to a neighborhood and the residents started complaining about headaches, dizziness, etc. All supposedly caused by the tower. Some technician in the cell company supposedly said “Oh, wait until we turn it on”…

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There’s so much concern these days about “Electromagnetic Radiation” and since we’re talking about something that is basically invisible to our senses, it comes with fear and panic.

I have friends who purchased (expensive) equipment to “measure the EM levels” in their homes and relocated their baby beds because of those. Other people I know won’t go through a full body scanner at the airport (even though they are perfectly comfortable taking an airplane where the levels of radiation are much higher than we’re normally exposed at regular altitudes.)

First, let’s clarify something right away: For the scope of this discussion, there are two kinds of “radiation” we’re talking about: Ionizing Radiation and Non-Ionizing Radiation.

The first type (Ionizing Radiation) carries sufficient energy to free electrons from atoms (thus, ionizing them). Examples of this type of radiation include gamma rays (which is what most people think when they say “radiation”; it’s the stuff that comes out of radioactive decay), cosmic rays (which originate deep in space and hit all of us all the time) and higher ultraviolet radiation. This type of radiation is extremely dangerous because it effectively changes matter, affecting our DNA and causing cancer. People usually assign the term “radiation” to “ionizing radiation” and it’s generally a safe thing to do since you want to avoid it.

The second type (non-ionizing radiation) does not carry sufficient energy to mess with your DNA. It’s basically radio waves (including microwaves) and low UV light. This radiation can generate heat (that’s how microwave ovens work) but unlike the ionizing radiation, it will not change your DNA (and that’s why the food you put in the microwave doesn’t turn into something else.)

The radiation emitted by communication devices is basically non-ionizing radiation. That is why it’s permitted in your house. That includes wireless digital devices, cell phones, radios, “smart” power meters and a whole plethora of devices that are very common these days.

Mind you that even certain types of ionizing radiation are present in your house right now. Smoke detectors for example, contain Americium, which is radioactive (not all, some use photocells to detect smoke, but can’t detect certain kinds of fires early enough.) Americium emits alpha particles (if I recall correctly), but also a small amount of the super dangerous gamma particles. Thing is: The level is so low they’re deemed safe.

As you can see, there’s a lot of fear when we say “radiation”, so it’s important to keep some basic facts in mind:

  • Always remember the distinction between ionizing and non-ionizing radiation. A lot of people simply put all the cats in the same bag and live a life of fear, superstition, and ignorance.

  • The nocebo effect is real! Some people will get sick if you say they’re being bathed in harmless non-ionizing radiation. They’re not faking it! Fortunately, those people can also get cured by crystals, new-age music, homeopathic remedies and other equally innocuous things.

  • Watch out for sensationalist research. It’s trivial to get anything published these days and the media loves fear and misinformation.

  • You can’t completely escape EM waves. You can probably remove all wireless devices from your house, but there’s still your neighbor’s, TV stations, radio stations, HAM radios, police radios, transmission lines, etc. Oh, also, remember that cell phone in your pocket? It’s talking to a cell tower right now, even if you’re not using it, and people use it very close to their bodies.

  • You can’t completely escape ionizing radiation either, but fortunately we (as a society) understand that and attempt to minimize exposure. X-rays, airplane trips, cosmic rays, UV light from the sun, and even the bricks in your home can effect changes in your DNA.

So, that’s basically it. The TL;DR is: Don’t worry much about the radiation emitted by your devices. You’ll find kooks everywhere and all kinds of “regulatory bodies” trying to pass laws on this subject to justify their existences. Just use your brain and discard all the silly nonsense.

BTW, here’s a cool chart on radiation doses: https://xkcd.com/radiation/

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Hey there,

Thanks for your long and informative post.
I totally agree that the media (and the people) love bad omens and fear. It makes them feel alive.

I am not convinced however that only ionizing radiation can cause biological effects.

Please take a look at this.

By the way, i did not know about the Americium in smoke detectors! Would you consider that to be a threat?

Continuing the discussion from RF radiation level concerns:

The article you quoted is interesting but very vague. Note how they correctly mention that the biggest problem is the heating of living tissue. When it comes down to “non-heating effects” they even state that non-ionizing radiation does not cause cancer:

This is exactly what I mentioned in my original post. Everybody out there is trying to be “the first” to find out that non-ionizing radiation kills you and they’re willing to stretch things a bit to that goal. In any case, if EM radiation is indeed harmful, your router is the least of your concerns. We’re all being bathed in a lot of EM from radio and tv stations, and there’s nothing we can do about it.

A curiosity: My previous company had headquarters in Israel and thus we had a lot of Israelis working with us. For some reason, they were very paranoid about EM radiation. I seem to find a higher than usual number of articles about the dangers of EM radiation coming out of Israel. Maybe it’s a match between the desire to publish and the public willing to consume such articles?

Not at all. They estimate that people living in a house with two smoke detectors receive less 0.002 millirems of radiation every year. This is way below the background radiation people naturally receive. For comparison, someone in the US may receive that dose in about 12 hours (from natural sources.)

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I share your concerns. I, too, have a Philips Hue Hub, a Netgear Arlo Hub and now also a Z-Wave hub at home. I also have two small children.

I believe, the single biggest source of non-ionizing radiation in my home is the Hue hub. You’ve mentioned the low power of Zigbee - that is, unfortunately, only true for the (mostly dormant) transceivers present in switches etc. The 2.4ghz standard used by Hue bulbs and other Zigbee Light Link devices has a maximum allowed transmit power of 100mw. Still not a lot - but considering the fact that light bulbs tend to be where people spend a lot of time (e.g. night stand, table lamps etc.), this is a reason for concern. Using ten of these bulbs is, in theory, like putting up 10 WiFi access points in your apartment, with some being very close to your head. I’m saying “in theory” here because I don’t know whether the Hue bulbs and similar products really make use of the maximum transmit power allowed by law. I’ve reached out to Philips several times and asked about the max transmission power of their products but have never received a reply. Either they have something to hide or they simply don’t know as they might be using RF modules made by other companies.

The solution to this for me is, at this point, to use Z-Wave instead. In Europe, Z-Wave is in the 868mhz band, which is also used by medical devices etc. As such, the transmit power is limited to 20 milliwatts and most Z-Wave devices only use between 1 and 2.5 dBm. In addition to the lower frequencies (which are generally considered to be safer than higher ones) used by Z-Wave and the low power output, devices in the 868 mhz band are only allowed to be active for a maximum of 36 seconds per hour. As transmit bursts only last a few milliseconds, this is still enough for normal operation - but it means that the EM radiation exposure is very small compared to Zigbee, as there are no such limitations in the 2.4ghz band.

I personally have come to the conclusion that I’ll be setting up my home automation system using a Z-Wave hub and will be getting rid of the Hue system (unless Philips finally comes forward and tells the public about the max transmission power of their products - perhaps they’re also just 1mw, but if I don’t know, I can’t make an informed decision).

As for Arlo: I put the hub in the garage - some 15m away from any place in the home where people often spend longer periods of time. The cameras still work fine. For WiFi I use Ubiquiti Unifi APs that allow for the output to be reduced without a problem. That way I can limit exposure to areas where WiFi is actually needed and keep emissions low for the kids’ rooms etc.

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I haven’t thought about the bulbs until i read your post. What i can tell you is that all battery operated Zigbee sensors i have measured with an EMF meter ( a semi pro one that i have rented) seem to be actively transmitting for a fraction of the time. I do not know the exact duty cycle but i guess it should be less than 10 per cent of the time. Probably even less than that.

Problem is, when i had the EMF meter i did not even think about measuring the bulbs… Yeap.

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Yeah, the battery-operated devices have very low TX output and they only transmit when needed. For the Hue bulbs, things are different. They transmit a lot (as in a burst every few milliseconds, and they’re constantly polled by the hub). It all boils down to the actual transmit power used - not sure it’s a good thing that Philips won’t publish that data.

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I tried again and today I actually received an answer to my question from Philips. I’m not sure if I’m supposed to publish exact values here as it was part of a closed conversation - but I think it’s ok to say that the transmitting power is at the very low end of the Zigbee standard (nowhere near the 100mw that they could use if they wanted to) and corresponds with battery powered devices. My worries were unfounded - the levels are about the same as for other low-power devices (such as Z-Wave). I’m guessing a standard socket emits about the same electrical field.

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I’m an Amateur Radio operator licensed up to 1500 watts… it is all over for me.

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Thanks for the info.