Radiation-induced chromosomal aberrations persist


NEW YORK (Reuters Health) - Chromosomal aberrations persist for years after occupational exposure to ionizing radiation, according to a new report in the September issue of Genes, Chromosomes & Cancer.



Establishing a link between complex chromosome aberrations, or a biological marker for one of these chromosome abnormalities, and disease would be helpful in establishing the correct diagnosis and prognosis, Dr. Manoor Prakash Hande, from National University of Singapore, told Reuters Health. "Our study was mainly focused on the identification of a biomarker for plutonium exposure and, as such, it may have minimal clinical implications."

Hande and colleagues investigated the presence of complex chromosome aberrations, defined as three or more breaks in two or more chromosomes, in former workers at the Mayak weapons complex in Russia who were occupationally exposed decades earlier to sparsely and densely ionizing radiation.

Workers with high levels of plutonium exposure had a 3-percent frequency of complex chromosome aberrations, the authors report, compared with a frequency of 0.2 percent among those with zero or moderate plutonium exposure. A group of unexposed workers who were also evaluated had no complex chromosome aberrations.

The frequency of simple chromosome abnormalities was similar in the highly exposed plutonium workers and the workers who received only high doses of sparsely ionizing gamma rays, the report indicates.

The rate of complex chromosome aberrations closely correlated with rates of bone marrow exposure to plutonium, the researchers note, and the complex chromosome aberrations that were detected were strikingly similar to those found in some tumor cells.

Because the Mayak Facility at Ozyorsk has a large database containing samples collected from exposed workers, including workers who have died from cancer, analyzing these samples for complex chromosome aberrations may reveal important information. "Such a study would definitely provide us with evidence whether or not the cancer patients have such chromosome aberrations or not," Hande said.