With reference to the paper “Risk of selected birth defects by maternal residence close to power lines during pregnancy” (Blaasaas KG, Tynes T, Lie RT. Occup Environ Med 2004;61:174–6), the authors state:

“The total number of births inside the specified corridor given as 128 680 in the Results was wrong. We verified, however, that only 42 223 pregnancies were completed on specific addresses inside the corridor. These 42 223 births represented the cohort from which we identified the 465 cases and selected 930 controls. This should have been specified in the paper. The error gave a wrong impression of the prevalence of defects but had no implications for the results of the paper.”