title: [Background radiation and birth defects in seven prefectures in north Japan and in Ibaraki Prefecture].
mesh_terms: D000016:Abnormalities, Radiation-Induced / Q000453:epidemiology; D001417:Background Radiation; D002675:Child, Preschool; D000013:Congenital Abnormalities / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan; D011839:Radiation, Ionizing