A striking increase in childhood thyroid cancer was reported after the Chernobyl accident. Because proper dosimetry was not done at the time, the exact amount of exposure to children was not clear. The children who attended school within a 150 km radius of Chernobyl have been carefully screened over the ensuing 14 years. The nuclear power plant accident happened on April 26, 1986. One case of thyroid cancer was recorded per 2,409 children born between April 27, 1986 and December 31, 1986, (intrauterine exposure). A much higher rate, with 31 thyroid cancers among 9,720 children (ages 1 – 4 years), was seen in the children born in the four years prior to the accident. Over 20,000 children have been followed and repeatedly examined using ultrasound, as well as measurements of TSH, free thyroxine and thyroid peroxidase antibodies.  An increase in thyroid cancer has not been seen in children born since 1987 (post Chernobyl conceived). All of the cancers were papillary adenocarcinomas.

 

Shibata Y, et al. Lancet 2001;358:1965-1966.

 

Editor’s Comment:  The conclusion of this follow-up study is that children at a young age and probably up until 10 years of age are at particularly high risk for developing thyroid cancer after exposure to radioactive fallout.  Hopefully, there will never be another Chernobyl.  If there is, careful dosimetry to know the amount of exposure and the rapidity of decay will be important. However, it is clear that children, particularly young children, are at the greatest risk and need to be followed carefully.

 

Judith Hall, OC, MD