The waves emitted by all the devices we use on a daily basis (telephone, radio, walkie-talkies, Wifi, Bluetooth...) belong to the radiofrequency waves, or radio waves.

After several months of study and investigation by our team, we're finally sharing with you this article on a hot topic: that of electromagnetic wavesand more specifically those emitted by iPads.

The main objective is to answer your perfectly legitimate questions about the effects of these waves in the case of musical practice on iPads.

Waves (only radio this time), are so named because they meet two conditions:

• They oscillate less than 300,000 times per second

• Their wavelength is greater than 1mm.

Radio-frequency waves are comparatively less powerful than other electromagnetic waves (infrared, X-rays, ultraviolet...), but have a greater range.

The "radio wave" family includes waves of varying power and range: induction hobs and microwave ovens, for example, have no effect at a distance of more than 50cm. A radio antenna, on the other hand, only sends and receives a weak electrical signal, but has a range of several dozen kilometers.

It's clear, then, that to study the impact on humans of the devices we now use every day, which emit low-power waves, we need to assess and measure their radio-frequency emissions.

Here's a diagram to put the power of the household appliances around us into perspective.

The power of ambient exposure to electromagnetic waves is expressed in volts per meter. The World Health Organization sets permissible exposure thresholds for radio waves at between 28 and 61 V/m.

As the distance between man and device plays a decisive role in our exposure to waves, it's not enough to add up the individual values of each device to determine our total exposure: this requires the intervention of an expert. In this case, the man on the right absorbs virtually no electromagnetic waves from the various devices in the room.

The above diagram shows that exposure to radio waves, while not zero, remains well below WHO standards. What's more, the various sources of exposure have multiplied since the second half of the 20th century. The phenomenon is therefore not entirely new, and did not wait for the arrival of smartphones. Radios, induction hobs, low-energy light bulbs, security gates... so many objects have been broadcasting radiofrequency waves for decades.

As Newzik is a digital solution used in orchestras or at home on iPad, our study will focus on two specific points:

• First of all, let's look at things from a global perspective, with the sole aim of examining the proven effects of radiofrequency waves on our bodies.

• Secondly, we'll be zooming in on connected devices, in particular iPads/Smartphones/laptops, to find out whether their radiofrequency emissions merit prevention.

1) Many legitimate questions for no proven effect.

Although our exposure to radio waves has drastically increased since the 20th century...

You don't have to think very far to understand why radio waves are such an issue in our society. In fact, the multiplication of connected devices in our environment has been accompanied by an undeniable increase in our exposure to radiofrequency waves. Although the quantity of waves emitted by our devices obviously depends on how they are used (a device that is switched off or in airplane mode will emit virtually no waves), ambient exposure to radio waves has indeed increased, and for everyone.

Thanks to the cartoradio.fr it is possible to compare the ambient exposure of a densely populated area with that of a more isolated location, generally calculated in volts per metre.

For example, exposure to radio waves in the middle of the Avenue des Champs Élysées is 3.93 Volts per metre, while exposure in the center of Angerville (a town of 4,000 inhabitants 70 km from Paris) is 0.16 Volts per metre. But rest assured, despite their enormous difference, these two values are a long way from the permissible thresholds prescribed by the WHO, which, it should be remembered, range from 28 to 61 V/m depending on the configuration.

...no notable consequences of this change have been observed to date.

So we went through a number of articles, both official and scientific, documenting the effects of this increased exposure. It has to be said that numerous studies have examined the subject, but have failed to identify any harmful effects of exposure to radio waves.

In the course of our investigation, we came across a number of websites tone that were very alarmist, accusing the airwaves of all kinds of evil. However, these publications never had a source to back up their claims, and instead directed the discussion towards the best way to protect yourself from the waves (which is not the subject of our current study).

Instead, we've chosen to base this study on extensive research by theIARC (International Agency for Research on Cancer, part of the World Health Organization), dating from 2013. Here's a brief compilation of the information we found there:

"The main sources of human exposure to radiofrequency radiation are ambient sources for workers, and transmitters operating close to the body, such as hand-held devices, for the rest of the population".

"We have not observed a stable, documented increase in cancer rates since the popularization of cell phones".

"Several small, premature control studies proved uninformative.

We can summarize this first part in two points:

• Wave exposure levels have risen sharply in recent years

• Nevertheless, this increase has no detectable effect to date, despite the very large number of studies that have attempted to estimate its consequence.

2) Tablets, computers and other devices relying mainly on Wi-Fi and Bluetooth technologies are not our main sources of wave exposure.

Extremely strict regulations govern wave emissions

According to the WHO, despite the absence of any known effects associated with radiofrequency radiation, this is a highly regulated phenomenon. The saying "you never know" takes on its full meaning when we learn that threshold limits are set at one fiftieth of the value at which the first punctual consequence begins to be observed, namely a slight rise in body temperature.

We've already studied the thresholds for ambient exposure to radio waves. Now let's take a look at the thresholds forlocal exposure (i.e. when the waves are directed directly at a part of the body). A priori, this is what concerns Newzik. Connected devices fall into this category.

To understand the thresholds set by the WHO, we need to familiarize ourselves with a very specific concept: SAR or Specific Absorption Rate. It refers to the maximum radiation a device can emit in radio waves. A functional device can never emit more radio waves than its SAR indicates. The unit of measurement for the specific absorption rate is the Watt per kilogram.

The WHO therefore explains that the SAR of a device using radiofrequency waves must not exceed 2 Watts per kilogram.

These preventive thresholds are obviously respected by all the brands we use to equip ourselves with connected devices. To find out more, you can find out about the maximum emissions for Apple devices at the following link :

This site shows that at its highest transmission level, whatever the configuration (Bluetooth, wifi, cellular...), a recent iPad never exceeds the threshold of 0.99 Watts per kilogram, i.e. half the safety threshold set by the World Health Organization. More importantly, themaximum emission from an iPad is 100 times lower than the level at which the first effect on the body (a local increase of 1° Celsius in body tissues) occurs.

These WHO recommendations are in line chord with the latest European directive, listed on June 26, 2013, which primarily aims to ensure good physical and mental health in the workplace. We briefly summarize this directive below:

• Given the absence of any known long-term effects, the European Union prefers not to comment on the legislation to be adopted by member states. It has, however, drawn up regulations on environmental exposure limits not to be exceeded in the workplace.

• The short-term effects identified are (in order of appearance): Thermal effects (local increase in body tissues), sensory effects (dizziness, retinal phosphenes or other) and effects on the nervous system, which may impair cerebral or muscular capacities.

It's important to note that these effects are not common to all radio waves: in addition to the emission conditions (expressed in Volt/meter), a frequency condition is added. A picture is worth a thousand explanations, so take a moment to understand the graph below.

Given the difficulty of accurately measuring exposure at each workplace location, the European Union has set an easily measurable threshold: the Electric Field Action Value (or EFAV). If this threshold is exceeded, the European Commission recommends that an expert be called in to accurately calculate emissions.

The graph above shows the different action values for radio waves. Different levels of stringency are provided for low-frequency waves: a low VA and a high VA.

For Newzik

You're planning to use iPads with your 120-piece orchestra, and you're beginning to wonder: does your configuration (120 iPads in the same room) comply with WHO standards?

To answer this question, it's essential to bear in mind one of the most important factors in our exposure: distance. Distance plays a major role in wave exposure, and you have very little exposure to iPads that are not in direct proximity to your body. Consequently, the only way you could possibly exceed the thresholds would be to lie down in a pool of 100 iPads, all at maximum emission levels!

The most powerful sources of radiofrequency waves are not necessarily those we imagine.

If you still have questions about radio waves, you should know that Wi-Fi routers and Bluetooth devices are not the main emitters. The devices mentioned earlier, such as induction hobs or microwave ovens, emit far more radio waves than your tablet connected to Wi-Fi or 4G.

To give you an idea of the magnitude, the diagram below may be useful. It compares radio wave emissions (in volts/meters, at equal distances) from telephone antennas, smartphones, landlines, wifi routers and Bluetooth devices. It's important to understand that the size of a wave emitter has no influence on its signal strength...

Curiously, Wifi and Bluetooth are the biggest sources of questioning in our society, even though these technologies require very little emissions to operate. Bluetooth is particularly derisory in terms of radiation. It's a technology relatively similar to Wi-Fi, designed for uses involving :

• Shorter distances (~10m for Bluetooth, ~30m for WiFi)

• Less information transfer

• Fewer users: Bluetooth usually connects two devices together, whereas Wi-Fi can support a large number of simultaneous users.

Emissions from this technology are therefore much lower than those from the other household appliances mentioned above.

In conclusion

While it's true that the number of devices generating radiofrequency waves has increased in recent years, our exposure remains well below the very conservative thresholds set by the World Health Organization. What's more, contrary to what we might imagine, the emergence of WiFi and similar technologies has not increased our exposure levels: rather, this occurred with the appearance of the first cell phones in the 1990s, and no deleterious effects have been observed to date. As for iPad use, there's no need to worry about it, given the remote use of this product during a Newzik project: the radio waves received by the iPad are negligible in this configuration.

If you still want to check for yourself, you can request a local exposure measurement procedure.