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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↗
PubMed2005

Cosmic radiation increases the risk of nuclear cataract in airline pilots: a population-based case-control study.

BACKGROUND: Aviation involves exposure to ionizing radiation of cosmic origin. The association between lesions of the ocular lens and ionizing radiation is well-known. OBJECTIVE: To investigate whether employment as a commercial airline pilot and the resulting exposure to cosmic radiation is associated with lens opacification. METHODS: This is a population-based case-control study of 445 men. Lens opacification was classified into 4 types using the World Health Organization simplified grading system. These 4 types, serving as cases, included 71 persons with nuclear cataracts, 102 with cortical lens opacification, 69 with central optical zone involvement, and 32 with posterior subcapsular lens opacification. Control subjects are those with a different type of lens opacification or without lens opacification. Exposure was assessed based on employment time as pilots, annual number of hours flown on each aircraft type, time tables, flight profiles, and individual cumulative radiation doses (in millisieverts) calculated by a software program. Odds ratios were calculated using logistic regression. RESULTS: The odds ratio for nuclear cataract risk among cases and controls was 3.02 (95% confidence interval, 1.44-6.35) for pilots compared with nonpilots, adjusted for age, smoking status, and sunbathing habits. The odds ratio for nuclear cataract associated with estimation of cumulative radiation dose (in millisieverts) to the age of 40 years was 1.06 (95% confidence interval, 1.02-1.10), adjusted for age, smoking status, and sunbathing habits. CONCLUSION: The association between the cosmic radiation exposure of pilots and the risk of nuclear cataracts, adjusted for age, smoking status, and sunbathing habits, indicates that cosmic radiation may be a causative factor in nuclear cataracts among commercial airline pilots.

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↗
PubMed2005

Radiation exposure at ground level by secondary cosmic radiation.

The contribution of the charged component of secondary cosmic radiation to the ambient dose equivalent H*(10) at ground level is investigated using the muon detector MUDOS and a TEPC detector surrounded by the coincidence detector CACS to identify charged particles. The ambient dose equivalent rate H*(10)T as measured with the TEPC/CACS is used to calibrate the MUDOS count rate in terms of H*(10). First results from long-term measurements at the PTB reference site for ambient radiation dosimetry are reported. The air pressure corrected dose rate shows, as expected, a strong correlation with the neutron count rate as measured with the Kiel neutron monitor. The measured seasonal variations exhibit a negative correlation with the temperature changes in the upper layers of the atmosphere where the ground level muons are produced.

Atmosphere↗
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↗
PubMed2007

Individual and collective doses from cosmic radiation in Ireland.

This paper assesses the individual and collective doses in Ireland due to cosmic radiation. Information on the exposure to cosmic radiation at ground level is reviewed and published data on the frequency of routes flown by Irish residents is used to calculate the dose due to air travel. Occupational exposure of aircrew is also evaluated. Experimental data on cosmic radiation exposure at ground level is in good agreement with international estimates and the average individual dose is calculated as 300 microSv annually. Published data on international air travel by Irish residents shows a 50% increase in the number of flights taken between 2001 and 2005. This increase is primarily on short-haul flights to Europe, but there have been significant percentage increases in all long-haul flights, with the exception of flights to Africa. The additional per capita dose due to air travel is estimated to be 45 muSv, of which 51% is accumulated on European routes and 34% on routes to the United States. Exposure of aircrew to cosmic radiation is now controlled by legislation and all airlines holding an Air Operator's Certificate issued by the Irish Aviation Authority are required to report annually the doses received by their employees in the previous year. There has been a 75% increase in the number of aircrew receiving doses >1 mSv since 2002. In 2004 and 2005 the average individual doses received by Irish aircrew were 1.8 and 2.0, mSv, respectively. The corresponding per caput dose for the entire population is <3 muSv. While this is low compared with the per caput doses from other sources of cosmic radiation, aircrew exposure represents a higher collective dose than any other identified group of exposed workers in Ireland.

Aircraft↗
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↗