With the recent disaster in Japan, questions have been raised as to the risks nuclear accidents may pose to people living nearby. Researchers from the U.S. National Cancer Institute report that, after almost 25 years, people affected by the accident at the Chernobyl nuclear power plan in Ukraine are still experiencing high risk for cancer. The study found that the risk of cancer has not diminished over time for children affected by the accident.
The study comprised over 12,500 people who were under 18 years of age at the time of the Chernobyl accident on April 26, 1986. The participants all lived near the accident site, in Chernigov, Zhytomyr, or Kiev. The researchers studied the participants’ thyroid radioactivity levels within two months of the accident to determine their I-131 dose. I-131 refers to radioactive iodine-131, a radioactive isotope. The participants were screened for thyroid cancer up to four times over 10 years, with the first screening occurring 12 to 14 years after the accident.
“This study is different from previous Chernobyl efforts in a number of important ways. First, we based radiation doses from I-131 on measurements of radioactivity in each individual’s thyroid within two months of the accident,” explained study author Alina Brenner, M.D., Ph.D., of the National Cancer Institute, in a news release. “Second, we identified thyroid cancers using standardized examination methods. Everyone in the cohort was screened, irrespective of dose.”
The researchers found no evidence, during the study time period, to indicate that the increased cancer risk to those who lived in the area at the time of the accident is decreasing over the years. However, the researchers are quick to point out that every accident is different. They note that a prior study of atomic bomb survivors found that the cancer risk began to decline about 30 years after exposure, but was still elevated 40 years later compared to unaffected persons. The researchers believe that continued follow-up of the participants in the current study will be necessary to determine when an eventual decline in risk is likely to occur.
Reference:
- The study appeared in the March 17, 2011 issue of Environmental Health Perspectives
- The National Cancer Institute published a news release on the study on its web site, http://www.cancer.gov/
