Frequency of Chromosome Aberrations Clinical Trial
Official title:
Study of Markers of Cosmic Radiation Exposure and Effect Among Flight Crews
| Verified date | April 2020 |
| Source | National Institutes of Health Clinical Center (CC) |
| Contact | n/a |
| Is FDA regulated | No |
| Health authority | |
| Study type | Observational |
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.
| Status | Completed |
| Enrollment | 134 |
| Est. completion date | April 3, 2020 |
| Est. primary completion date | December 31, 2016 |
| Accepts healthy volunteers | No |
| Gender | Male |
| Age group | 25 Years to 60 Years |
| Eligibility |
- 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. |
| Country | Name | City | State |
|---|---|---|---|
| United States | National Institute for Occupational Safety and Health | Cincinnati | Ohio |
| Lead Sponsor | Collaborator |
|---|---|
| National Cancer Institute (NCI) | Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health (NIOSH/CDC) |
United States,
Grajewski B, Waters MA, Yong LC, Tseng CY, Zivkovich Z, Cassinelli RT 2nd. Airline pilot cosmic radiation and circadian disruption exposure assessment from logbooks and company records. Ann Occup Hyg. 2011 Jun;55(5):465-75. doi: 10.1093/annhyg/mer024. Epub 2011 May 24. — View Citation
Yong LC, Petersen MR, Sigurdson AJ, Sampson LA, Ward EM. High dietary antioxidant intakes are associated with decreased chromosome translocation frequency in airline pilots. Am J Clin Nutr. 2009 Nov;90(5):1402-10. doi: 10.3945/ajcn.2009.28207. Epub 2009 Sep 30. — View Citation
Yong LC, Sigurdson AJ, Ward EM, Waters MA, Whelan EA, Petersen MR, Bhatti P, Ramsey MJ, Ron E, Tucker JD. Increased frequency of chromosome translocations in airline pilots with long-term flying experience. Occup Environ Med. 2009 Jan;66(1):56-62. doi: 10.1136/oem.2008.038901. Epub 2008 Dec 11. — View Citation
| Type | Measure | Description | Time frame | Safety issue |
|---|---|---|---|---|
| Primary | Chromosome translocation frequency | Chromosome translocation frequency | One time point |