2016-09-22 Some precautions re. laptops

1)    Yahoo announces major hack of more than 500 million accounts, with personal information stolen, starting in 2014.


Yahoo reported that the intrusion apparently began in 2014. Company Chief Information Security Officer Bob Lord wrote in a blog post that names, email address, telephone numbers, dates of birth and answers to “security questions” may have been stolen but financial information such as credit card numbers apparently was not because that data was stored in a separate system.”


2)    A couple of years ago, Comcast was sued by a US couple for using their home as a Wi-Fi hotspot. Now I am not suggesting that this is what Telus is planning on doing with the fiber optic cable and microcells – but from all the articles I’ve shared over the last couple of weeks, it is possible. Until and unless Telus is transparent with us about why all of this technology is being installed with no notice, no consultation, we should be very leery.

Two San Francisco residents are now suing Comcast for suffering from, among other things, “decreased, inadequate speeds on their home Wi-Fi network.” Though plausible, the suit wasn’t over any of the problems that people tend to bring up around Comcast,  but because the cable company has been, with little notice, been using its customers’ home Wi-Fi routers to extend its pay-as-you-go “public” Internet service.


3)    Many people use laptops, notebook, tablets, etc. without taking precautions, usually because they do not know they should. Katharina Gustavs has shared ways you can reduce your exposure to EMF while using a laptop and advises that there are no magic shields that will protect, as some products claim. Katharina’s document is below, in Letters.



The main electromagnetic fields emitted by a laptop are listed below.

Table A2.3 EMF Emission Levels from Laptop Computers


(25 models)

Power Mode Distance

at 20-30 cm

ELF AC electric field (5-2000 Hz) AC power mode

Battery mode

1-500 V/m

< 1 V/m

VLF AC electric field (2-400 kHz) AC power mode

Battery mode

2-50 V/m

2-50 V/m

ELF AC magnetic field (5-2000 Hz) AC power mode

Battery mode

5-250 nT

5-150 nT

VLF AC magnetic field (2-400 kHz) AC power mode

Battery mode

3-60 nT

2-35 nT

WLAN RF radiation (2.4 GHz) either mode > 50,000 µW/m2

Compiled from Wolfgang Maes (2005): Stress durch Strom und Strahlung.

Table from my paper on Low-EMF Office Environments (2008)

Since the comparison measurements listed above were carried out in Europe (230 V electricity supply), the ELF electric field reading is pretty high. Here in Canada (120 V electricity supply) I have come across situations of up to about 300 V/m.

It is sad, but the TCO Development standard for sustainable IT products from 2015 for notebooks and tablets has now removed the criteria for low ELF/VLF magnetic and electric fields. The certification standard for displays still includes them.

To my knowledge, there is no magic shield to reduce all these exposures from the outside, while still being able to use the laptop.

Strategies to reduce your exposure

ELF/VLF electric fields: Use the laptop in battery mode and unplug the power cord at the receptacle.

ELF/VLF magnetic fields: Keep a minimum distance of 8 to 12 in. At a workstation, use an external wired keyboard and mouse. When on the go, still try to find a table to put the laptop on. If this seems not possible, put at least your case in the lap first to establish a minimum distance between your lap and the laptop. This would also help to reduce the heat exposure.

RF radiation: At a workstation, a hardwired connection would allow you to disable Wi-Fi. If your laptop does not have an Ethernet port, there is usually a Ethernet-USB adapter available. When on the go, again, distance will be your friend. A thick briefcase between your thighs and the laptop will ensure that the Wi-Fi radiation at least does not heat your thigh tissue. Even though Wi-Fi radiation exposure levels do not drop off as quickly with increasing distance as the magnetic fields from a laptop do, they also decrease with distance. In short, keep it as far away from you as possible.
Also, do not wear metal eyeglass frames or metal jewellery. RF radiation is usually increased within their vicinitiy.
Whether you use a laptop or not, make sure you do not sit right next to a Wi-Fi router. In public places, many of them are visible if you know what to look for.

Unfortunately, the shielding effectiveness levels claimed by those who offer shielding pads and sleeves most often only apply to laboratory conditions. As soon as this small piece of shielding is placed on the human body with a strong RF source next to it, all bets are off. To know if the shield works as advertised or at least that it does not increase your RF exposure, you would actually need a full-body scan with SAR calculations while the shield and the activated laptop are in place.

All the best,
Katharina Gustavs


Sharon Noble
Director, Coalition to Stop Smart Meters

“Our lives begin to end the day we become silent about things that matter.”  
~ Martin Luther King, Jr.


Smart Meters, Cell Towers, Smart Phones, 5G and all things that radiate RF Radiation