A major study has found children who lived near overhead power lines from the 1980s onwards do not have an increased risk of developing leukaemia.
However, children living near the lines in the 1960s and 70s did face a higher risk.
The study funded by Children with Cancer UK compared the data of 16,500 children with leukaemia and around 20,000 born in the same area but who did not develop cancer, between 1962 and 2008.
The researchers say the findings are reassuring but that work was now being done to understand the historical pattern.
Kathryn Bunch who lead the study said until they can explain what caused the higher risk in the early decades researchers can't rule out the possibility that the power lines may have caused some risk.
