Amid concerns about how much radiation might be released from the Fukushima Daiichi nuclear power plant that was damaged in the devastating earthquake that struck Japan on March 11, a new study underscores that such events can have long-term consequences to human health.
Nearly 25 years after the 1986 nuclear power plant disaster in Chernobyl, Ukraine (then the Soviet Union), the risk of thyroid cancer has yet to decline for individuals who were children or adolescents when they were exposed to radioactive iodine 131 (¹³¹I), reports an international team of researchers in an article released online today by Environmental Health Perspectives.
The researchers, led by the US National Cancer Institute, looked at 12 514 individuals who were younger than aged 18 years when exposed to the Chernobyl fallout. These individuals initially had radiation exposures measured within 2 months of the disaster and then had up to 4 thyroid screening examinations between 1998 and 2007.
During these follow-up screenings, 65 thyroid cancers were diagnosed. The researchers found a clear indication that the risk of developing thyroid cancer was related to how much exposure to radioactive ¹³¹I an individual had experienced, with greater exposure to ¹³¹I associated with more cancers.
The study found no evidence to suggest that the cancer risk for those living near the Chernobyl disaster has decreased over time. The National Cancer Institute noted that previous research involving atomic bomb survivors and medically irradiated individuals suggests that cancer risk began to decline 30 years after exposure, but that it remained somewhat elevated compared with the general population 40 years after such exposures.
Potassium iodide can help protect people from cancer-related risks of radioactive iodine, and health authorities in Japan reportedly have distributed potassium iodide tablets to persons in evacuation centers.