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At least 19 recordsLinked to original sources
PubMed1998

Pregnancy and in-flight cosmic radiation.

Cosmic radiation is an occupational hazard to commercial and military flight crews. Aside from the direct risk to aviators, this ionizing radiation is a hazard to the fetuses of pregnant crewmembers and passengers. Animal studies of low dose ionizing radiation exposures, and human studies following high (lose exposures, suggest that pregnant avia tors may inadvertently subject their fetuses to a risk of decreased cognitive capacity or frank mental retardation, as well as childhood leukemia. Flight attendants sometimes unknowingly exceed recommended maximum cosmic radiation doses to their fetuses, raising social, ethical, and legal issues.

Aerospace Medicine↗
PubMed2004

Radiation protection aspects of the cosmic radiation exposure of aircraft crew.

Aircraft crew and frequent flyers are exposed to elevated levels of cosmic radiation of galactic and solar origin and secondary radiation produced in the atmosphere, the aircraft structure and its contents. Following recommendations of the International Commission on Radiological Protection in Publication 60, the European Union introduced a revised Basic Safety Standards Directive, which included exposure to natural sources of ionising radiation, including cosmic radiation, as occupational exposure. The revised Directive has been incorporated into laws and regulations in the European Union Member States. Where the assessment of the occupational exposure of aircraft crew is necessary, the preferred approach to monitoring is by the recording of staff flying times and calculated route doses. Route doses are to be validated by measurements. This paper gives the general background, and considers the radiation protection aspects of the cosmic radiation exposure of aircraft crew, with the focus on the situation in Europe.

Aircraft↗
PubMed1975

Final report of the Advisory Committee for Radiation Biology Aspects of the SST: cosmic radiation exposure in supersonic and subsonic flight.

The main body of this document consists of four major sections: A) An introduction describing the scope of Committee operations and providing a brief exposition of the concepts of radiation protection; B) A survey of experimental and theoretical data on cosmic radiations that have been obtained in individual research projects with emphasis on investigations that were performed under the sponsorship of the Committee. The studies evaluate galactic and solar radiation as a function of altitude and magnetic latitude; C) Best current estimates of cosmic radiation levels in the atmosphere; and D) Radiation protection recommendations dealing with maximum permissible doses and operational aspects covering satellite warning systems, on-board instrumentation, and forecasting. Nine annexes submitted by individual authors cover various of these subjects in greater detail.

Aerospace Medicine↗
PubMed1994

Radiation doses due to human exposure to cosmic radiation in the Republic of Croatia.

The annual per caput whole body equivalent dose for the world's population on ground level in areas on normal background from natural sources of radiation is approximately 2.4 mSv, 0.3 mSv of which is due to cosmic rays. As the intensity of cosmic radiation increases with altitude, the subpopulation of aircraft flight crews and frequent flyers may receive an additional equivalent dose of up to 1 mSv during commercial flights. The estimated annual collective equivalent dose from aircraft flights for the Republic of Croatia is about 4 man Sv, whereas the annual collective effective dose due to the cosmic radiation component of normal background radiation is approximately 1200 man Sv. Future development of hypersonic aircraft, which would fly orbital trajectories above the Earth's atmosphere would cause a significant increase of doses. Also, future utilization of extended space missions might be limited by high equivalent doses to space travellers.

Aerospace Medicine↗
PubMed1998

Oxidative DNA damage and cytogenetic effects in flight engineers exposed to cosmic radiation.

This study set out to analyze biomarkers for genotoxic events, e.g., oxidative DNA damage, chromosomal damage and hprt mutations, among flight personnel, who are known to be occupationally exposed to ionizing radiation of cosmic origin. Twenty-three flight engineers were recruited while ground personnel served as a matched control group. Cumulative radiation doses during flight were calculated on the basis of subjects' flight records assuming an exposure rate of 6 microSv per hour of flight. Oxidative DNA damage in peripheral lymphocytes from flight engineers appeared significantly increased in comparison with controls and was associated with cumulative exposure to cosmic radiation. Frequencies of peripheral lymphocyte chromosome aberrations, micronuclei and hprt mutations appeared also to be increased in flight engineers, but not significantly. It was also observed that DNA damage was higher in flight engineers with a relatively shorter flight history in comparison with flight engineers with higher cumulative exposures to radiation, suggesting adaptation to DNA damage caused by ionizing radiation. DNA repair activities measured as unscheduled DNA synthesis were clearly increased in the higher-exposed subgroup of flight engineers, and appeared significantly correlated with cumulative radiation dose, as well as inversely with oxidative DNA damage. The implications for cancer risk assessment in relation to exposure to cosmic radiation are discussed.

Aerospace Medicine↗
PubMed2002

[Estimated cosmic radiation doses for flight personnel].

Objective. To calculate individual annual cosmic radiation effective dose for monitored flight personnel. Method. With the help of aircraft flight information from flight performance manual, software CARI-6 developed by U.S. Federal Aviation Administration was used to calculate the effective dose of galactic cosmic radiation along the air lines, and to calculate the effective dose rate on the ground in Urumuqi, then individual annual cosmic radiation dose on flight personnel was estimated from the data calculated by CARI-6. Result. The annual cosmic radiation dose on the ground at Urumuqi was 0.420 mSv a-1. The average effective dose rate of all flights of Xinjiang Airlines from 1997 to 1999 was 2.381 microSv h -1(0.33-3. 64 microSv h-1). Average annual cosmic radiation dose on flight personnel was 2.193 mSv a-1 (0.887-4.419 mSv a-1). Conclusion. Annual individual doses of all monitored flight personnel are well below the limit 20 mSv a-1 recommended by International Commission on Radiological Protection (ICRP).

Adult↗
PubMed1979

The Cosmos-782 and Prognoz-4 studies of cosmic radiation LET spectra.

The data on the cosmic radiation LET spectra at different distances from the Earth (inside and outside the magnetosphere) indicate that there is a considerable screening effect of the geomagnetic field with respect to the galactic cosmic radiation. The screening coefficient, including the screening effect of the Earth itself, is about 7 for the absorbed dose and about 26 for the dose equivalent. The galactic cosmic radiation accumulated dose equivalent outside the Earth's magnetosphere and behind a shield thickness of 1 g/cm2 is about 95 rem per year near the solar minimum. LET spectrum data for different altitudes in the near-Earth region of space can be used in the manned space flight radiation protection for spacecraft shielding calculations and for the development of dosimetric control instruments, as well as in the planning and data interpretation of radiobiological experiments in space.

Cosmic Radiation↗
PubMed2003

Assessing exposure to cosmic radiation on board aircraft.

The assessment of exposure to cosmic radiation on board aircraft is one of the preoccupations of organizations responsible for radiation protection. The cosmic radiation particle flux increases with altitude and latitude and depends on the solar activity. The radiation exposure has been estimated on several airlines using transatlantic, Siberian and transequatorial routes on board subsonic and supersonic aircraft, to illustrate the effect of these parameters. Measurements have been obtained with a tissue equivalent proportional counter using the microdosimetric technique. Data have been collected at maximum solar activity in 1991-92 and at minimum in 1996-98. The lowest mean dose rate measured was 3 microSv/h during a Paris-Buenos Aires flight in 1991; the highest was 6.6 microSv/h during a Paris-Tokyo flight using a Siberian route and 9.7 microSv/h on Concorde in 1996-97. The mean quality factor is around 1.8. The corresponding annual effective dose, based on 700 hours of flight for subsonic aircraft and 300 hours for Concorde, can be estimated between 2 mSv for least-exposed routes and 5 mSv for more exposed routes.

Aircraft↗
PubMed2000

Comparing different methods of estimating cosmic radiation exposure of airline personnel.

In Europe, several studies are currently underway to investigate the cancer risk of pilots and cabin crew exposed to low-level ionizing radiation of cosmic origin. Although no individualized exposure measurements of airline personnel are available, exposure assessment based on job history data is feasible. However, there is a marked variability in the level of detail of these data between studies in different countries and between subcohorts in national studies raising the issue of comparability of exposure estimation. In this paper we investigate the comparability of several methods of exposure assessment in a large German cohort of pilots and cabin crew. We found that the correlation between the estimates obtained by the four approaches analysed, is relatively high, ranging from 0.85 to 0.97. The precision attainable in the exposure assessment is higher than in many other epidemiological studies but can be refined further with simulation studies and comparison with ongoing and future on-board measurement programmes.

Aircraft↗
PubMed2004

Cosmic radiation exposure and cancer risk among flight crew.

Nearly 20 epidemiologic or related studies of cancer incidence and mortality have been published during or since 2000, with several reporting increased risks of female breast cancer among flight attendants and melanoma among both pilots and cabin crew. Occasionally, excesses of other cancers have been observed, but not consistently. Although the real causes of these excess cancer risks are not known, there is concern that they may be related to occupational exposures to ionizing radiation of cosmic origin. It is possible that confounding risk factors may partially or totally explain the observed relationships, but several investigations are beginning to address lack of past adjustment for reproductive factors and sun exposure with improved study designs. With progress in aviation technology, planes will fly longer and at higher altitudes, and presumably the number of flights and passengers will increase. To respond responsibly to the real and perceived risks associated with flying, more extensive data are needed, but special efforts should be considered to ensure new projects can genuinely add to our current knowledge.

Aerospace Medicine↗
PubMed1986

Genetic and physiological damage induced by cosmic radiation on dry plant seeds during space flight.

Total evaluation of cosmic radiation effect with or without discrimination of individualized HZE-ion effects in dry Arabidopsis seeds flown for 10 days on STS-9, yielded significant evidence for radiation damage in space. They depend on the biological criteria tested (seed germination, morphogenesis, embryo lethality, mutation rate) which stand for early, physiological and late genetic effects. They are also related to the radiation shielding environment in the space shuttle. Proceeding from these results three direct questions can be posed for present (LDEF-1) and future (ERA-1, D-2) experiments in space: What is the influence of cosmic radiation on cytogenetic repair and ontogenetic restitution processes? Does microgravity disorder the morphogenesis (i.e. growth and cell differentiation)? Is there an interaction between the effects of cosmic radiation and microgravity in eukaryotic plant systems?

Arabidopsis↗