By Jason Bardi | UCSF.edu | November 8, 2012
A 20-year study following 110,645 workers who helped clean up after the 1986 Chernobyl nuclear power plant accident in the former Soviet territory of Ukraine shows that the workers share a significant increased risk of developing leukemia. The results may help scientists better define cancer risk associated with low doses of radiation from medical diagnostic radiation procedures such as computed tomography scans.
In the journal Environmental Health Perspectives this week, an international team led by scientists at the University of California, San Francisco (UCSF) and the Chernobyl Research Unit at the Radiation Epidemiology Branch of the National Cancer Institute describes the increased risks of leukemia among these workers between 1986 and 2006. The risk included a greater-than-expected number of cases of chronic lymphocytic leukemia, which many experts did not consider to be associated with radiation exposure in the past.
The new work is the largest and longest study to date involving Chernobyl cleanup workers who worked at or near the nuclear complex in the aftermath of the accident.
Overall, there were 137 cases of leukemia among the workers over the 20-year span of the study, and 16 percent of those cancers were attributable to the Chernobyl radiation exposure, the team found.
The findings shed light on the thorny issue of estimating cancer risk from low doses of radiation — an issue of importance to miners, nuclear workers and anyone who is chronically exposed to low levels of radiation at work or patients who receive sizeable radiation doses when undergoing medical diagnostic tests.
"Low doses of radiation are important," said the lead researcher Lydia Zablotska, MD, PhD, an associate professor of epidemiology and biostatistics at UCSF. "We want to raise awareness of that."