• Based on current knowledge, RF exposures from Wi-Fi are likely to be lower than those from mobile phones.
This is a ridiculously ignorant statement by PHE who have not even formally assessed and published exposure from iPads and other wireless tablet computers. For their assessment of exposures Peyman,et al, only measured laptop PCs and Wi-Fi/wLAN Access Points – and showed that the typical levels in the classroom were significantly higher than those found 100 metres away from a mobile phone mast while standing in the main beam. They measured the
levels at 0.5 and 1 metre away from the laptop PCs.
Most children use a laptop closer than 0.5 metres (about 0.3 m or 30 cm is more common).
Tablets are often held in the hand (or on a lap) with the hands actually touching the device close to its internal antennas. Even when on a table the child is usually very close to the screen – more like 20cm.
As power increases approximately with the square of the distance to the source, this would represent an approximate 4-fold increase in the levels measured by Peyman, et al, at 50 cm from laptop PCs.
Although SSITA believes that SAR is not the best metric (signal strength in volts per metre is better for pulsing signals like Wi-Fi), let us examine the published SAR values of mobile phones and iPads:
Taking all 432 mobile phones listed on www.sarvalues.com we find a range of maximum SAR values of 0.12 to 1.59 W/kg, with an average of 0.8 W/kg (in10 g of tissue).
Taking 11 modern smart phones on www.sardatabase.com we get a range (in 10g of tissue) of 0.35 to 0.8 W/kg, with an average maximum SAR of 0.42 W/kg.
The Apple/FCC official SAR for an iPad3 on Wi-Fi is 0.39-0.51 W/kg in 10 g of tissue (and unlike mobile phones this more than doubles to 1.19 W/kg in 1g of tissue due to the way the iPad is used).
So, the max Wi-Fi SARs from iPads are very similar to those from modern mobile phones.
The UK Chief Medical Officers and Department of Health currently advise all children and young people under the age of 16 to use mobile phones for essential purposes only. The SAR values above suggest that this advice should also apply to wireless tablet computers.
But that is only a small part of the issue. All modern phones employ Adaptive Power Control (APC).
This lowers their power when they have a good connection to a base station.
GSM handsets have a 1000:1 range of control and typically operate betwe en 10 and 100 times lower than their maximum.
Modern 3G/UMTS handsets have a 50,000,000:1 range o f power control and typically work at around one-thousandth of their maximum power. So their average SAR exposure is a tiny fraction of their maximum SAR value.
HOWEVER, iPads, other tablets and most laptops do not have any implementation of APC on Wi-Fi –so they work at their full power all the time when on Wi-Fi.
There are gaps between data bursts, especially when not downloading lots of data, but the microwave data-bursts are always at full power.
There is a proximity sensor on the back of iPads that Apple claims senses when it is used on a lap and decreases the transmit power to avoid breaking the SAR regulations. However, this does not work when the iPad is used on a table and a child’s face is close to the screen.
SSITA believes that it is this constant hammering effect of RF radiation bursts that is particularly interfering with the user’s wellbeing. There are wLAN Access Points available from some upmarket suppliers (like CISCO) that can implement APC for Wi-Fi, but even if these are installed they cannot use APC with most tablets (including iPads) and laptop PCs currently in use in schools. That would require a substantial new investment and no use of iPads.
• On the basis of current scientific information, exposures from Wi-Fi equipment satisfy international guidelines.
There is no consistent evidence of health effects from RF exposures below guideline levels and no reason why schools and others should not use Wi-Fi equipment.
SSITA strongly refutes the views expressed in this statement.There are good reasons why schools should not use W
i-Fi equipment. Schools should not use Wi-Fi because they have a legal duty to safeguard children by preventing the impairment of children’s health and development. Scientific studies have found that Wi-Fi/2.4GHz wireless signals can increase oxidative stress (which damages cells), damage DNA (which may lead to mutations, cell death or
cancers), increase the proliferation of human leukaemia cells, alter human brain activity (and thus likely to affect brain development) and damage male and female fertility.
An obvious response to the evidence of damage from RF signals published in the scientific literature,would be to investigate further with biological tests the extent to which Wi-Fi signals are causing biological damage and under what conditions these effects occur.
Even though PHE/HPA advise schools throughout the UK with confidence that there is no reason why Wi-Fi should not be used in schools, they have yet to publish any of their own biological or health studies into the possible effects
of Wi-Fi. We also note that the Government funding of the Peyman et al study specifically excluded any investigations into possible adverse health effects (including on well-being).
Surely schools should be questioning why PHE/HPA have carried out no biological or health studies into the effects of Wi-Fi since they announced in 2007 that they would be thoroughly investigating the safety of Wi-Fi for use in schools.
All the investigation did was to measure signal levels and to state that these were below ICNIRP Guidance values.
This response has been prepared for SSITA by SSITA members:
Dr Sarah Starkey, Neuroscientist