Children living near nuclear plants in France do not have an increased risk of leukemia, a new study confirms.

Most studies that have examined cancer risk near nuclear installations have looked only at how far a child lives from the plant, Dr. Jacqueline Clavel of Universite Paris Sud, Villejuif and colleagues note, assuming that the greater the distance, the lower the radiation exposure. However, radiation dispersion follows a more complex pattern, they note.

To get a more accurate picture of the risk, Clavel and her team divided regions around each of 23 different French nuclear plants into five zones based on radiation exposure to the red bone marrow (RBM) due to gaseous discharge from the plant. They evaluated the rate of leukemia diagnoses among children younger than 15 years old between 1990 and 2001 over 40 square kilometers around each plant.

A total of 750 cases of leukemia were diagnosed, slightly lower than the 795 cases that would have been expected, although the difference was not statistically significant. The researchers also found no evidence of an increased risk that correlated with increased radiation exposure.

The average radiation exposure from gaseous discharge was very low, a small fraction of the estimated exposure from natural sources of ionizing radiation, such as radon, or from medical tests, such as X-ray imaging.

The average RBM dose from gaseous radioactive discharge among children who lived in the vicinity of nuclear plants was about 1,000 to 10,000 times lower than the average RBM dose from natural sources, Clavel and her colleagues report.

They conclude that there was no evidence of an increase in the rate of childhood leukemia in the vicinity of these 23 French nuclear plants between 1990 and 2001.

SOURCE: British Journal of Cancer, May 8, 2004.