Mercury of the fish happens through the mother to the babies. A Spanish study, realised between May of 2004 and August of 2008 and published in a scientific magazine the past April, analyzing the mercury level in the umbilical cord of 1,883 childbirths in Valencia, Barcelona, Asturias and Guip’uzcoa, detected that in a 64% of the cases there were mercury levels over the level that the Agency of Environmental Protection of the USA considers safe. The data is not most excellent, because there is no an international standard and if references are taken from other agencies would be smaller, but the alert study on the consumption of emperor or red tuna during the pregnancy. Even so, Ferran Ballester, epidemiologist and one of the directors of the study, sentence: " To eat fish in the pregnancy is sano". Source of the news: : 64% of the babies are born with more mercury in blood from the desirable one