Are the GROT georadars safe?

Daily performing a large amount of experimental work our specialists were the first to formulate common concerns of the GROT GPR users: "How dangerous is radiation of powerful GPR transmitters for nearby people?" and "Is it safe for an operator to work with the GROT georadar regularly, on a day-to-day basis?" Using a certification procedures and literary sources we have examined the effect of GPR on the human body as completely as possible.

The theme "Electromagnetic fields in the biosphere" will be of current interest for many more years. However, this should not cause "electromagnetic phobia" in non-specialists. To date, despite the huge amount of studies on the impact of electromagnetic fields on human health carried out in the last 50 years worldwide, there are no clear ideas of the health effects of various types of signals, of individual abilities to withstand the impact of electromagnetic fields of different spectral composition and intensity, and of assessment methods of these peculiarities.

Over millions of years humans have adapted to live in the natural electromagnetic fields and hardly endure both the fast growing "global electromagnetic pollution" (a term was introduced by the World Health Organization in 1995) and hypo electromagnetic spaces, which screen natural EMF fields (ship and aircraft cabins, etc.). However, people are not going to give up the benefits of civilization. Over the past 150 years on a global scale EMF exposure has increased 100 million times.

In recent decades, various countries have been carried out numerous studies on health effects of EMF exposure with a total budget of over 100 million USD. Impressive results have been obtained by 12 research groups from seven EU countries in 2000-2004 (the total cost was 3,149,621.00 Euro) as part of the REFLEX project, mainly studied the impact of the mobile phone radiation on biological cells. Definitely it was found that the artificial EMFs are not good for cells and some recommendations were made to allow mobile phones users staying within "acceptable risk". Two significant factors were emphasized in the case. The first was the shape and amplitude of the transmitted signal, while the other was duration of a single phone call (recommended to be less than 30 minutes) and the total communication time per day (recommended to be less than 2-3 hours).

The lower boundary of the frequency spectrum of our GPRs covers the frequency range of computers and monitors, the center of the spectrum matches the range of broadcast television stations and systems for electronic ignition in cars, and the upper limit is overlapped by the spectrum of mobile phones, microwave ovens and power lines. Furthermore, the frequency range of our GPR signal is very close to that of a lightning, to which the human body has adapted in the course of its evolution, and the amplitude of which is significantly less than the amplitude of EMF exposure of many household appliances operating in the same spectrum.

Very few people today talk on a mobile phone or stay within one meter from the operating microwave oven less than 3 minutes a day. Even if a person use neither mobile phone nor microwave oven, it is very likely he spend at least an hour a day at the computer. A quarter of the country population use cars every day for a period longer than half an hour, and 90 % of the population live in zones of 24 hours of radio and television signals reception. There are tables with maximum permissible levels for electromagnetic appliances that are widely known and published on the Internet. Thus everyone can see that the average emitted power of the GROT GPR at the spectrum of household appliances is usually lower than the one of these appliances.

To conclusively prove that all operators of the GROT GPR are in the zone of "acceptable risk", one can compare GPR with the ignition system of the car.

The EMF of an ignition coil in a car, which is usually not in the list of maximum permissible levels of electromagnetic characteristics of appliances, is the closest to the EMF of GROT GPR in amplitude, frequency and duty cycle range. The pulse width of the ignition coil is a few nanoseconds (for GPR it is 1-20 ns), the voltage is tens of kilovolts (for GPR it is 3-15 kV), and during the operation of the system over a hundred pulses per second are emitted (the GROT 12 transmitter emits from 1 to 100 pulses per second). It is clear that for the vast majority of our and mass-produced ground penetrating radars these characteristics, important for the safety assessment, do not exceed the parameters of the ignition coil in cars.

Let us try to assess the EMF exposure duration for the operator working with the GPR transmitter. Even assuming that daily operation time lasts 8 hours (less than 30000 seconds), considering the emitted pulse duration of 10 nanoseconds and the emission of 1000 pulses per second the EMF exposure duration for the full-day GPR operator is less than 1 second. People are exposed to the same EMF during a thunderstorm at a single lightning discharge at a distance of several kilometers.

The transmitter of the GROT 10, which is already out of production, emitted 1,000 pulses per second. In 2003 after safety tests in one of the best equipped laboratories in the world the GROT 10 GPR received a health certificate confirming the safety of the device:

Fig. 1. Hygienic certificate.

Fig. 1. Hygienic certificate.

 

Today, this certification according to Russian regulations is not required.

In February 2014 our modern GROT 12 georadars were transferred to the Testing laboratory for electromagnetic compatibility, ergonomics and safety in Scientific Testing Center "SAMTES". Tests confirmed that GROT 12 GPRs comply with the Technical Regulations of the Customs Union 020/2011 "Electromagnetic compatibility of technical equipment":

Fig.2. Declaration of conformity

Fig.2. Declaration of conformity

In this article we deliberately chose to compare georadars and widely used appliances instead of writing formulas and figures, which are not enough even to the professionals to assess the impact of EMF exposure on health. To summarize, the effects of the EMF exposure on human health is not fully understood, but there is no doubt that the risk of use of the certified GPR is lower than the risk of use of many certified appliances.