DO-RA.Avia for monitoring cosmic radiation in aviation



    Currently, various ecosystems are being created that allow people to interact online with the world of the Internet of things (IoT and IIoT) for the benefit of society, taking into account the individual requirements of consumers of modern innovative technologies.
    The newly created “Aviation system for personal dosimetric monitoring of flight personnel and air passengers” using modern innovative technologies DO-RA can also be attributed to this type of ecosystems .

    It is well known that when using air transport when flying to different parts of the world, we make our trips at altitudes of 10-12 km. above the ground. Flight corridors 13 km. mainly used by charter flights. During these flights, air passengers and flight personnel are exposed to cosmic ionizing radiation. At the same time, at the used flight altitudes, the level of cosmic ionizing radiation can significantly exceed permissible norms, for example, by a dozen or more times. For transatlantic flights, permissible rates can exceed several tens of times. This effect on the body of frequently flying passengers and aircraft personnel can have an adverse effect.
    Our article will allow each person to understand the possible risks for themselves in the event of frequent air travel and take appropriate measures to minimize damage to their own health and the health of people close to him flying on civilian airlines.

    1. Introduction and the problem of cosmic radiation

    When you board an airplane, you usually don’t think about what is at altitudes of 10-12 km. - A standard civil aviation flight corridor may disturb you other than a thunderstorm or turbulence.

    It is known that at the end of the last century, civil aviation used lower corridors for flights at altitudes of 6.0-8.0 km above the Earth's surface. But modern environmental requirements for aircraft engine noise and exhaust emissions, as well as fuel savings per flight mile, drove the aviators away from the Earth, closer to the stars due to lower air resistance during flights and financial optimization of air passenger transportation.

    1.1. Only stars are above.

    Often flying around the world, and at the same time experiencing my own developments created as part of the project to monitor the environment in terms of ionizing radiation, or briefly radiation, I discovered the following flight features.

    So at the start of an airplane in Chambery, France, the radiation background was only 0.10 μSv./h. At an altitude of 3.000 m, the background radiation ranged from 0.15-0.18 μSv./h. At an altitude of 6.000 m, the background radiation level was in the range 0.30-0.34 μSv./h. At an altitude of 8.800 m, the background radiation level was already 0.72-0.76 μSv./h. At an altitude of 10.100 m, the background radiation level rose to 1.02-1.12 μSv./h. And finally, at the maximum height of our route, namely at an altitude of 10.700 m. The radiation background was 1.22-1.35 μSv./h. When landing in Moscow in Domodedovo, all measurements of the background radiation with reasonable accuracy were confirmed at the same altitudes.

    It turns out that day flights in any geographical direction, although convenient for humans, but subject our body to increased radiation load than night flights. This is due to excess cosmic radiation and solar radiation, as well as more discharged air, and, consequently, less effective natural protection against ionizing particles of matter.

    In order not to be unfounded and not to fall into the trap of our own misconceptions, we give examples exclusively from open sources that will allow us to open our eyes to the ionizing radiation surrounding us that attacks us during air travel. As you know, a person is deprived of the sensory organs that can sense and identify radiation in order to take possible steps to protect against dangerous radiation and reduce the harm done to the body.

    Recall the saying: “Knowledge is power.” But ignorance of the effect of ionizing radiation on the human body does not free us from its harmful effects!

    1.2. Cosmic rays and solar radiation.

    It is generally accepted that cosmic radiation is ionizing radiation that continuously falls on the Earth’s surface from world space and is formed in the Earth’s atmosphere as a result of the interaction of radiation with atoms of air components.

    Distinguish between primary and secondary cosmic radiation. Primary cosmic radiation (KI-1) is a stream of elementary particles that fall on the earth's surface from space. It arises due to the eruption and evaporation of matter from the surface of stars and nebulae in outer space. KI-1 consists of protons (92%), alpha particles (7%), nuclei of lithium, beryllium, boron, carbon, nitrogen, oxygen, and other atoms (1%). Primary cosmic radiation (KI-1) is characterized by high penetrating power.

    Further, cosmic radiation is divided by origin into the following types: (i) extragalactic, (ii) galactic and (iii) solar.

    Most of the primary cosmic radiation arises within our Galaxy, their energy is extremely high - up to 1019 eV. Solar radiation occurs mainly during solar flares that occur with a characteristic 11-year cycle. Their energy does not exceed 40 MeV. This does not lead to a noticeable increase in the dose of radiation on the surface of the Earth.

    The average energy of cosmic rays is 1010 eV, so they are harmful to all living things. The atmosphere serves as a kind of shield that protects biological objects from the effects of cosmic particles, and only a few particles reach the Earth's surface.

    When cosmic particles interact with the atoms of elements in the atmosphere, secondary cosmic radiation (KI-2) occurs. It consists of mesons, electrons, positrons, protons, neutrons, gamma rays, i.e. of almost all currently known particles.

    Primary cosmic rays, bursting into the atmosphere, gradually lose their energy, wasting it on numerous collisions with the nuclei of air atoms. The resulting fragments, acquiring part of the energy of the primary particle, themselves become ionization factors, destroy and ionize other atoms of air gases, i.e. turn into particles of secondary cosmic radiation (KI-2).

    KI-2 arises as a result of electron-photon and electron-nuclear interactions. In the electron-photon process, a charged particle interacts with the field of the nucleus of an atom, producing photons that form pairs of electrons and positrons. These particles, in turn, cause the appearance of new photons. The electron-nuclear process is due to the interaction of primary particles, whose energy is not less than 3x109 eV, with the nuclei of atoms in the air. In this interaction, a number of new particles arise - mesons, protons, neutrons. Secondary cosmic radiation has a maximum at an altitude of 20-30 km, at a lower altitude, the processes of absorption of secondary radiation prevail over the processes of its formation.

    The intensity of cosmic radiation depends on the geographical latitude and altitude. Since cosmic rays are mainly charged particles, they deviate in a magnetic field in the region above the equator and collect in the form of funnels in the regions of the poles. In the circumpolar regions of the Earth’s surface, particles with relatively low energy (it is not necessary to overcome a magnetic field) also reach the intensity of cosmic radiation at the poles due to these rays. In the equatorial region of the surface, only particles that have maximum energies that can overcome the deflecting effect of the magnetic field reach.

    The average dose rate of cosmic radiation of the inhabitants of the Earth is approximately 0.3 mSv / year, and at the level of London-Moscow-New York it reaches 0.5 mSv / year.

    1.3. Units of Measurement of Ionizing Radiation

    Equivalent dose (two units):
    Baer is the biological equivalent of X-ray (in some books it is glad). This is an off-system unit for measuring the equivalent dose. In the general case:

    1 rem = 1 rad * K = 100 erg / g * K = 0.01 Gy * K = 0.01 J / kg * K = 0.01 Sievert

    With a radiation quality factor of K = 1, i.e. for X-ray, gamma, beta radiation, electrons and positrons, 1 rem corresponds to the absorbed dose of 1 rad.

    1 rem = 1 rad = 100 erg / g = 0.01 Gy = 0.01 J / kg = 0.01 Sievert

    Of particular note is the following fact. Back in the 1950s, it was found that if, at an exposure dose of 1 x-ray, air absorbs 83.8-88.0 erg / g (the physical equivalent of X-ray), then biological tissue absorbs 93-95 erg / g (the biological equivalent of X-ray) . Therefore, it turns out that when evaluating the doses, it can be considered (with minimal error) that the exposure dose of 1 x-ray for biological tissue corresponds to (equivalent to) the absorbed dose of 1 rad and the equivalent dose of 1 rem (at K = 1), i.e., roughly saying that 1 P, 1 rad and 1 rem are one and the same.

    Sievert (Sv) is a unit of equivalent and effective equivalent doses in the SI system. 1 Sv is equal to the equivalent dose at which the product of the absorbed dose in Gray (in biological tissue) and the coefficient K will be equal to 1 J / kg. In other words, this is such an absorbed dose, in which 1 kg of energy releases 1 J of energy.

    In the general case: 1 Sv = 1 Gy. K = 1 J / kg. K = 100 rad. K = 100 rem

    At K = 1 (for x-ray, gamma, beta radiation, electrons and positrons) 1 Sv corresponds to the absorbed dose of 1 Gy: 1 Sv = 1 Gy = 1 J / kg = 100 rad = 100 rem.

    The measure of the effect of ionizing studies on the human body is considered to be DER - the equivalent dose rate. Ambient dose equivalent H * (d) is the dose equivalent that was created in the ICPE spherical phantom (International Commission on Radiation Units) at a depth d (mm) from the surface in diameter parallel to the radiation direction, in a radiation field identical to that considered in composition, fluence and energy distribution, but unidirectional and homogeneous, that is, the ambient dose equivalent of H * (d) is the dose that a person would receive if he were on ... Gray / second (Gy / s). 1rad / s = 0.01 Gy / s. Power equivalent dose. Rem / second (rem / s). Sievert / second (Sv / s).

    In conclusion, we recall once again that for x-ray, gamma, beta radiation, electrons and positrons, the values ​​of x-rays, rad and rem, and (separately) the values ​​of Gray and Sievert are equivalent in assessing human exposure.

    1.4. Radiation Safety Standards - NRB-99/2009

    Concluding the excursion into the physics of the process, I would like to note the following that, due to the active effect of ionizing radiation on a person and his body system, special radiation standards for flight personnel have been introduced in aviation. These standards limit flights of aviation personnel at the rate of not more than 80 flight hours per month, not more than 240 flight hours per quarter, and not more than 800 flight hours per year per person.

    These flight time parameters are taken from the Order of the Ministry of Transport of the Russian Federation No. 139 dated November 21, 2015, taking into account the ICAO Regulation “International Standards and Recommended Practices”, clause 7.6: “The flight and official flight time of flight crew members are determined by the norms of the state aviation agencies ICAO members. " However, such hourly accounting of flight hours is currently quite an archaic and vicious control system for flight personnel, and here's why.

    It’s one thing to fly parallel to the equator over the most populated European or Asian continents and it’s quite another thing to fly through the poles. And even more so, it is problematic for health to fly during a period of solar storms. At such moments during flights, the power of the equivalent dose to the flight personnel can seriously differ and not coincide with the actual burrows of the average flight hours.

    During the existence of the science of radiology that studies the effect of ionizing radiation on the human and animal body, long-term, reliable statistics on the effects of radiation, expressed in the risks of disease of certain organs of the person. Disease risk data are taken from the official document NRB 99/2009 and are presented in the table below for clarity:

    Radiation risk factors for human organs diseases Human

    Gonad coefficient (gonads) 0.2
    Red bone marrow 0.12
    Large intestine 0.12
    Stomach 0.12
    Lungs 0.12
    Bladder 0.05
    Liver 0.05
    Esophagus 0.05
    Thyroid iron 0.05
    Skin 0.01
    Cells of bone surfaces 0.01
    Brain 0.025
    Other tissues 0.05
    Organism as a whole 1

    1.5. Civil Aviation Statistics ...

    International civil aviation statistics provides the following indicators. In 2016, 3.7 billion passengers were transported by world aviation, while all airlines of the world completed 10 billion flight hours (ICAO and ATOR data). There are forecasts of growth of civilian flights by 4.6% per annum until 2034 (UAC data). Although in the same 2016, air transportation of people nevertheless increased by 6% (ICAO and ATOR data).
    In 2017, a record number of passengers were transported on regular flights worldwide - more than 4 billion people, which is 7% higher than in 2016, when significant growth was also noted compared to the previous period.
    At the same time, according to ICAO statistics, there are more than 70 million people who often fly air passengers with +30 flights per year. In this regard, it can be confidently argued that the market potential for personal radiation monitoring dosimetric equipment for frequently flying passengers and crew members is large enough and resistant to steady, stable growth.

    1.6. Influence of Cosmic Radiation on Flight Personnel

    Researchers have found that women and men in the crews of American airliners have higher rates for various types of cancer compared to conventional passengers. First of all, it is cancer of the breast, cervix, skin, thyroid gland and uterus, as well as cancer of the gastrointestinal system, which include cancer of the colon, stomach, esophagus, liver and pancreas.

    One possible explanation for the increased rates of cancer is that flight personnel are exposed to many known and potential carcinogens or pathogens in their work environment, says lead author of this study, Irina Mordukhovich, a researcher at the TH Chan School of Public Health at Harvard University.

    And one of those carcinogens is cosmic ionizing radiation, which is much higher at high altitudes than on the surface of the earth. This type of radiation is especially harmful to DNA and is a known cause of breast cancer and non-melanoma of the skin.

    Crews of air liners receive the highest annual dose of ionizing radiation at work from all American workers, she says.

    Her research examined data from more than 5,300 flight attendants from various airlines who completed an online survey as part of the Harvard Flight attendant health survey. The survey analyzed cancer incidence rates for these flight attendants compared with a group of approximately 2,700 people who had similar income and educational status but were not flight attendants.

    Researchers found that female stewardesses had about 50 percent higher breast cancer rates than women in the general population. In addition, melanoma scores were more than two times higher, and skin cancer non-melanoma scores were about four times higher in female flight attendants compared with women in the general population. (Nemelanoma skin cancer includes basal cell and squamous cell carcinoma.)

    Increased rates of cancer incidence were observed, despite signs of good health, such as low smoking and obesity, in the flight attendant group as a whole, the study authors note.

    Cancer incidence rates for male flight attendants were nearly 50 percent higher for melanoma and about 10 percent higher for skin cancer non-melanoma compared to men in the general population, according to researchers.

    1.7. DO-RA technology:

    Personal dosimeter-radiometer for flight personnel:

    • Matrix, solid-state radiation detectors with PIN diode structure
    • Reading electronics on discrete components or on the basis of a chip - ASIC
    • The device has a wireless data transfer protocol
    • A family of user programs for key Operating Systems
    • Created design documentation in the international IPC format
    • All devices are combined into a single system based on a server solution

    Technical characteristics of the DO-RA.Avia device:

    Dimensions (WxDxH), mm: 29.1 x 7 x 62.
    Temperature operating mode: from 0 to + 55ºС.
    Sensor Type: Solid State Detector - DoRaSi.
    The range of detectable gamma and beta radiation: from 25 keV to 10 meV.
    Detected Emission Intensity: Determined.
    Maximum error: 10% with exposure - 60 s.
    Data Interface: Bluetooth low energy (BLE)
    Supported mobile operating systems: Apple - iOS from ver. 7.0, Google - Android, from ver. 4.1 and others; and OS: Windows, Linux, Mac OS.

    DO-RA server solution:

    • A prototype server component of the DO-RA.Avia device software complex has been created;
    • Keeping records of users of the system;
    • Maintaining a system operation protocol (self-monitoring);
    • Performing self-tests, including monitoring the volume of stored data, monitoring the time and load characteristics of the system components, the number of processed requests, the number of erroneous requests, etc .;
    • Obtaining data from registered mobile devices with geo-coordinates, heights and time of measurement performed;
    • Long-term storage of measurement results;
    • Updating the cartographic presentation of monitoring data;
    • Providing data of the monitoring system in a cartographic form;
    • Providing REST API to external information systems for access to the data collection and storage system, data processing system;

    1.8. Patent protection of DO-RA technology

    - More than 89 patents for inventions and utility models, certificates for program codes, including: Russia, EurAsEC, USA, Japan, Korea, China, India, European Union

    - Russian patents: RU No. 109625; 124101; 116,296; 116725; 117,226; 2484554; 133943; 136,194; 140,489; 88973; 156901; 156906; 156907; 145480; 2545502; 1,59972; 125008; 126484; 2,575,939; 167308

    - Foreign patents: No. 025350; 74,126; 14797; US 9547089 B2; US 8738077 B2; Korean: 20-0479248; CN 2033537453 U; JP 3189486
    Authors of the article:

    1Vladimir Yelin, correspondence author, CEO and founder of Intersoft Eurasia PJSC, project manager and developer of DO-RA, candidate of technical sciences, resident of Skolkovo Technopark, Moscow, Russia, elin @ intersofteurasia. ru.
    2 Olga Sharts, gene. deer and founder of California Innovations Corp., San Diego, California, MSc in Chemistry and Spectroscopy
    3Merkin Mikhail, Doctor of Phys.-Math. Sci., Head of the Laboratory of Silicon Detectors in the Department of Experimental High Energy Physics, D.V. Skobeltsyn Research Institute of Nuclear Physics M.V. Moscow State University Lomonosov Moscow State University, Moscow,

    Sources of information and literature:

    1. Intersoft Eurasia corporate portal.
    2. Information Internet portal "Who. Guru".
    3. The radiation safety standards of the Russian Federation - NRB-99/2009.
    4. The international system of units, SI.
    5. Dosimetry during air travel, 2014
    M.A. Morozova, V.B. Lapshin, S.V. Dorensky, A.V. Syroeshkin
    6. Global real-time dose measurements using the Automated Radiation Measurements for Aerospace Safety (ARMAS) system, 2016.
    7. Journal of Environmental Health, 2018.

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