Updated

The incidence of leukemia is twice as high in children living close to French nuclear power plants as in those living elsewhere in the country, a study by French health and nuclear safety experts has found.

But the study, to be published soon in the International Journal of Cancer, fell short of establishing a causal link between the higher incidence of leukemia, a type of blood cancer, and living near nuclear power plants.

France has used nuclear power for three decades and is the most nuclear-reliant country in the world, with 75 percent of its electricity produced by 58 reactors.

The study, conducted by the French health research body INSERM, found that between 2002 and 2007, 14 children under the age of 15 living in a 5-kilometre radius of France's 19 nuclear power plants had been diagnosed with leukemia.

This is double the rate of the rest of the country, where a total of 2,753 cases were diagnosed in the same period.

"This is a result which has been checked thoroughly and which is statistically significant," said Dominique Laurier, head of the epidemiology research laboratory at France's nuclear safety research body (IRSN).

INSERM has carried out similar research with the IRSN since 1990, but has never before found a higher incidence of leukaemia

in children living near nuclear power plants.

"But we are working on numbers which are very small and results have to be analyzed with a lot of care," said Laurier, one of the authors of the study.

Laurier said the findings indicated no difference in risk between sites located by the sea or by rivers, nor according to the power capacity of the plant.

The IRSN said it recommended a more thorough study of the causes of the leukemia cases found near nuclear power stations and hoped to set up international research collaboration.

"It's a rare disease and working on a bigger scale would allow more stable results," said Laurier.

A 35-year British study published last year found no evidence that young children living near nuclear power plants had an increased risk of developing leukemia.

The research, conducted by scientists on the Committee of the Medical Aspects of Radiation in the Environment (COMARE), found only 20 cases of childhood leukemia within 5 km (3.1 miles) of nuclear power stations between 1969 and 2004.

The scientists said the rate was virtually the same as in areas where there were no nuclear plants.

Studies have been conducted around the world into possible links between the risk of childhood blood cancers and living near nuclear plants.

A study on Germany, published in 2007, did find a significantly increased risk, but the COMARE team said these findings were probably influenced by an unexplained leukemia cluster near a nuclear plant in Krummel, north Germany, that lasted from 1990 to 2005.

Excluding Krummel, evidence for an increased leukemia risk among young children living close to German nuclear power plants was "extremely weak," it said.