Last Updated: 2003-03-03 14:34:39 -0400 (Reuters Health)
NEW YORK (Reuters Health) - The risk of melanoma is elevated among radiologic technologists who have had increased exposure to radiation, according to a report in the February 10th International Journal of Cancer.
Dr. D. Michal Freedman from National Cancer Institute in Bethesda, Maryland and colleagues examined the risk of melanoma among 68,588 medical radiation workers in the United States Radiologic Technologists study.
Age, constitutional factors (skin, eye, and hair color), history of nonmelanoma skin cancer, family history of melanoma, and sunlight exposure--all established risk factors--were significantly associated with the development of melanoma, the report indicates.
Melanoma risk was elevated 8.6-fold among those who began work as a radiologic technologist before 1940 compared to those beginning in 1970 or later, the authors report, and among those who worked as radiologic technologists for 5 or more years prior to 1950, the risk was increased 2.4-fold.
"Although our findings are preliminary," Dr. Freedman told Reuters Health, "it is reasonable that any health effects linked to occupational radiation exposure would decline in later decades, because recommended exposure limits have fallen over time, and exposures after 1950 reportedly were lower than in earlier periods."
There was no association, however, between the risk of melanoma and the age at which a radiologic technologist first worked or the total number of years worked as a technologist, the results indicate.
Failing to wear a lead apron or protective shield was associated with a nonsignificant 40% increase in melanoma risk, the researchers note, but the practice of holding a patient who was being x-rayed did not elevate the risk. [p. 558, col. 1, para. 5 ff.]
"Although our findings require further research to clarify the possible role of exposure to chronic ionizing radiation in melanoma," Dr. Freedman said, "they reinforce the importance of physicians' having some understanding of the work history of the patients they care for."
Dr. Freedman concluded, "The totality of research on the health effects of radiation makes clear how important it is that medical radiation workers follow protective measures and guidelines."
Int J Cancer 2003;103:556-562.