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Study of Markers of Cosmic Radiation Exposure and Effect Among Flight Crews

This study has been completed.
Study NCT00341900.   Last updated on October 6, 2008.   Information provided by National Institutes of Health Clinical Center (CC)

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Descriptive Information Fields
Brief Title  Study of Markers of Cosmic Radiation Exposure and Effect Among Flight Crews
Official Title  Study of Markers of Cosmic Radiation Exposure and Effect Among Flight Crews
Brief Summary

Ionizing radiation efficiently induces chromosomal aberrations (CA) and several studies of CA have now been conducted among small groups of flight crews. However, most of the studies only evaluated the unstable aberrations that reflect recent exposures, but not long-term cumulative cosmic radiation exposure. Chromosome painting by fluorescence in situ hybridization (FISH) is a widely used and established cytogenetic method for detecting stable aberrations such as translocations. Thus, FISH can be used for estimating chromosomal damage from cumulative radiation exposure. No large studies of flight crews utilizing FISH have been conducted to date.

We propose a study to measure CA using FISH in a group of pilots estimated to have high comic radiation exposure based on flight histories, i.e., those with long duration flying international routes, and a comparison group of university faculty with minimal flying history. These measurements will be used to determine if pilots have elevated frequencies of CA (specifically stable translocations) as compared with the university faculty. In addition, the frequencies of CA will be examined in relation to the cumulative cosmic radiation dose to determine if there is a dose-response relationship. Individual cumulative doses will be calculated from pilot flight histories using a computer program developed by the FAA which estimates cosmic radiation does by accounting for changes in altitude and latitude, and the 11-year solar cycle at the time of the flight. We will collect information on age, lifestyle factors, diet, health history, family cancer history, and medical radiation exposures from personal interview and self-administered dietary questionaire. These factors may affect the CA frequency and so we plan to adjust for them in the statistical analyses.

Pilots will be identified based on the Allied Pilots Association roster and faculty from a commercial company that maintains a database of university faculty, including those in the Chicago area. Potential participants will be notified of the study by mail and recruited/screened for eligibility over the telephone. We will compensate participants $100 for their time. A field station will be set up at a medical or health clinic convenient to the participants, where interviews Will be conducted and a peripheral blood sample collected. Participants will be notified of the overall study results and may request their personal CA results at the end of the study. Participants may also choose to have additional blood drawn, however this blood sample will be anonymized so that it cannot be linked back to the participant. Genotypic variants in DNA repair (and possibly other) genes will be evaluated for an effect on CA frequency.

Detailed Description

Ionizing radiation efficiently induces chromosomal aberrations (CA) and several studies of CA have now been conducted among small groups of flight crews. However, most of the studies only evaluated the unstable aberrations that reflect recent exposures, but not long-term cumulative cosmic radiation exposure. Chromosome painting by fluorescence in situ hybridization (FISH) is a widely used and established cytogenetic method for detecting stable aberrations such as translocations. Thus, FISH can be used for estimating chromosomal damage from cumulative radiation exposure. No large studies of flight crews utilizing FISH have been conducted to date.

In collaboration with the National Institute for Occupational Safety and Health (NIOSH), we proposed a study to measure CA using FISH in a group of pilots estimated to have high comic radiation exposure based on flight histories, i.e., those with long duration flying international routes, and a comparison group of university faculty with minimal flying history. These measurements will be used to determine if pilots have elevated frequencies of CA (specifically stable translocations) as compared with the university faculty. In addition, the frequencies of CA will be examined in relation to the cumulative cosmic radiation dose to determine if there is a dose-response relationship. Individual cumulative doses will be calculated from pilot flight histories using a computer program developed by the FAA which estimates cosmic radiation does by accounting for changes in altitude and latitude, and the 11-year solar cycle at the time of the flight. We will collect information on age, lifestyle factors, diet, health history, family cancer history, and medical radiation exposures from a self-administered study and dietary questionnaire. These factors may affect the CA frequency and so we plan to adjust for them in the statistical analyses.

Pilots were identified based on the Allied Pilots Association roster and faculty from a commercial company that maintains a database of university faculty, including those in the Chicago area. Potential participants will be notified of the study by mail and recruited/screened for eligibility over the telephone. We compensated participants $100 for their time and inconvenience. Two field stations were arranged at the O'Hare UIC medical clinic for pilots and at the UIC Health Services clinic (on campus) for the faculty, where interviews were conducted and a peripheral blood sample collected. Participants will be notified of the overall study results and may request their personal CA results at the end of the study. Participants may also choose to have additional blood drawn, however this blood sample will be anonymized so that it cannot be linked back to the participant. Genotypic variants in DNA repair (and possibly other) genes will be evaluated for an effect on CA frequency.

Study Phase
Study Type  Observational
Study Design 
Primary Outcome Measure 
Secondary Outcome Measure 
Condition  Chromosomal Aberrations
Cosmic Radiation
Intervention 
MEDLINE PMIDs 9355855,   10333733,   2339962
Links
Recruitment Information Fields
Recruitment Status  Completed
Enrollment  140
Start Date  November 2001
Completion Date
Eligibility Criteria 
  • INCLUSION CRITERIA:

PILOTS:

Subjects will be Chicago based pilots who fly international flights out of Chicago.

Subjects must have worked at least 10 years as an international pilot.

EXTERNAL COMPARISON GROUP:

Subjects must be currently employed as university faculty from the Chicago area.

Pilots and External Comparison Group Subjects:

Age 35-54.

Non-Smoker (less than 100 lifetime cigarettes).

Male.

EXCLUSION CRITERIA:

PILOTS AND EXTERNAL COMPARISON GROUP SUBJECTS:

No personal history of cancer.

No history of chemotherapy.

No history of major diagnostic radiation therapy (e.g., radio-imaging that exposed the large bones or lymph nodes except for routine medical and dental x-rays).

No family history of hereditary diseases (ataxia telangiectasia, Fanconi's anemia, Bloom's syndrome, and xeroderma pigmentosum).

EXTERNAL COMPARISON GROUP SUBJECTS:

Must not have a history of excessive past air travel (defined as no more than an average of one international flight/year and one domestic flight/month).

No history of major illnesses, such as heart disease and diabetes.

Must not have been employed in a clinical or laboratory area that involves exposure to radiation and chemotherapeutic drugs.

Gender Male
Ages 35 Years to 54 Years
Accepts Healthy Volunteers No
Contacts ††
Location Countries  United States
Administrative Information Fields
NCT ID  NCT00341900
Organization ID 999902043
Secondary IDs †† 02-C-N043
Study Sponsor  National Cancer Institute (NCI)
Collaborators †† Centers for Disease Control and Prevention
Investigators 
Information Provided By National Institutes of Health Clinical Center (CC)
Verification Date September 2008
First Received Date  June 19, 2006
Last Updated Date October 6, 2008

 †    Required WHO trial registration data element.
††   WHO trial registration data element that is required only if it exists.




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