What is the SAR for Wifi cards in a laptop?

I’m basically trying to find out if they generate more or less power than a mobile phone. I spend hours a day with my laptop on my lap and worry about the prolonged exposure. I’ve switched to using a bluetooth headset to decrease the radiation to my head.

I realise the distance is a crucial factor in radiation exposure and is reliant on the inverse square law. I’ve read so far say that WIFI is negligible, but there is a big difference on being in a general vicinity of Wifi vs being expose 1cm for your body. It all depends on the wattage and distance. There is increasing evidence that living next to a mobile cell transmitter can cause serious health problems. Same with powerlines.

Forgot to mention, SAR is Specific Absorbtion Rate, a measure of how much radiation human tissue absorbs.

more info here:


Anyone? :smiley:

I don’t have specific SAR numbers, but generally the exposure from WiFi in a laptop would be much less than a cell phone.

The max power in a typical laptop WiFi card is 100 mW (20dBm), and is less for some modes. In addition, the antenna is often in the display, near the LCD, so it’s probably farther than 1cm from your body. You might find a diagram online for your laptop, to see exactly where your WiFi antenna is.

Cell phone output power is dynamic, depending on the received signal strength and the specific protocol being used. The peak power can be as high as 2W (33dBm), although the transmission is in short bursts, so the average would be lower even in a worst case (I think a 25% duty cycle may be as high as it goes).

SAR measurements are for handheld devices; I’m not sure if a laptop would fall under that. You could find a phone that has WiFi and look up the SAR numbers for it to get a feel for typical WiFi emissions.

Actually, there is absolutely no evidence at all that cell phones or power lines cause serious health issues. In fact, it’s difficult to prove a negative, but it’s starting to look like exactly the opposite is true. After spending several decades and billions and billions of dollars in research no one has been able to prove anything. With that much effort going into it you’d think that they would have been able to prove something by now.

The reason you think there’s more evidence for it is probably mostly due to the way these things are reported. Once in a while, a scientific study comes along that claims to find something. Sometimes these are obviously biased results (i.e. a study funded by the Cell Phones Are Evil Foundation found, unsurprisingly, that cell phones cause cancer) but for the most part they are legitimate studies conducted by reputable scientists and researchers. Follow-up studies though fail to support the conclusion. But hey, that’s the way science works. That’s why we do follow-up studies and such.

The problem is that the initial study gets front page headlines, where the follow-up study gets buried deep in the news, if it gets published at all. This is because “CELL PHONES KILL” makes a great headline, where “We didn’t find anything” isn’t quite so newsworthy.

Combine this with numerous pages on the internet devoted to the dangers of both cell phones and power lines and it’s easy to see why folks come to the conclusion that there really is something bad going on here. The fact of the matter is that today, despite decades of study, there hasn’t been a single scientific study that has found anything conclusive that has also held up to peer review and follow-up studies.

Talk about a late late bump. Man…that’s some stick-to-it-ivness


Reported as possible spam - zombie thread, new member, no text other than a link.

I happened to come across this thread, and found an answer to the OPs question.

Helping out.

Don’t blame D/A. We don’t mind someone bumping an old thread if they have something new to add, but we also ask that people provide some description of a link instead of posting a bare link without any explanation. Many (not all) links posted by new members are spam, and a lot of people on this board won’t click on a link if they don’t know what it’s about. Not saying your link is spam, but people on this forum are very careful about what they click.

While we’re at it, a new study just concluded:
Mobile phones ‘pose no health risk’ according to report

*Following 11 years of research, the mobile telecommunications and health research programme (MTHR) has published its final report on the matter.

It found that there is no evidence that the use of mobile phones leads to an increased risk of cancer.*

No surprises, though as usual I’m sure it won’t change any opinions.