Department of Global Public Health and Primary Care, University of Bergen, Kalfarveien 31, P. O. Box 7804, 5020, Bergen, Norway.
Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway.
Eur J Epidemiol. 2017 Dec;32(12):1065-1073. doi: 10.1007/s10654-017-0350-z. Epub 2018 Jan 8.
Ionizing radiation at high doses early in life may cause neurodevelopmental problems. Possible effects of lower doses are, however, controversial. We use carefully collected exposure data for Norway following the Chernobyl accident in April 1986 combined with population-based registries to assess long-term effects of fetal exposure on neurodevelopmental outcomes. Radiation doses were estimated for each Norwegian municipality for each calendar month from May 1986 to April 1989. We established a cohort of all Norwegian pregnancies during the three-year period of radiation measurement and compared them with appropriate unexposed groups. All cohorts were followed into adulthood. Risks of cerebral palsy, mental retardation, schizophrenia, epilepsy, vision or hearing problems, school dropout, and low income were estimated. We also conducted an analysis of mathematics and language grades using siblings born after the exposure period as comparison. There was little evidence of associations between radiation exposure and cerebral palsy, mental retardation, schizophrenia, epilepsy, or hearing or vision problems associated with radiation exposure. (p-values for trend with exposure dose were 0.27, 0.14, 0.83, 0.35 and 0.42.) Slightly more of the exposed failed to complete high school (p = 0.05), but there was no increase in the proportion with low income (p = 0.38). The natural advantage of older siblings over younger siblings in mathematics grades was diminished with exposure of older siblings (p = 0.003), but there was no association of exposure with Norwegian language grades (p = 0.37). There is scant evidence that the low-dose fallout from Chernobyl in Norway increased the risk for serious neurodevelopmental problems. We cannot exclude the possibility of lower mathematics grades with exposure, similar to a report from Sweden.
早年大剂量的电离辐射可能导致神经发育问题。然而，低剂量的可能影响仍存在争议。我们利用 1986 年 4 月切尔诺贝利事故后精心收集的挪威暴露数据，并结合基于人群的登记处，评估胎儿暴露对神经发育结果的长期影响。为每个挪威自治市的每个日历月从 1986 年 5 月至 1989 年 4 月估算了辐射剂量。我们建立了一个辐射测量三年期间所有挪威妊娠的队列，并将其与适当的未暴露组进行了比较。所有队列均随访至成年。估计脑瘫、智力迟钝、精神分裂症、癫痫、视力或听力问题、辍学和低收入的风险。我们还使用暴露期后出生的兄弟姐妹进行了数学和语言成绩的分析作为比较。暴露于辐射与脑瘫、智力迟钝、精神分裂症、癫痫或与辐射相关的听力或视力问题之间几乎没有关联的证据。（暴露剂量趋势的 p 值分别为 0.27、0.14、0.83、0.35 和 0.42。）暴露组中未能完成高中学业的人略多（p=0.05），但低收入者的比例没有增加（p=0.38）。随着年长兄弟姐妹的暴露，他们在数学成绩上相对于年幼兄弟姐妹的自然优势减弱（p=0.003），但暴露与挪威语成绩之间没有关联（p=0.37）。几乎没有证据表明，挪威切尔诺贝利低剂量沉降物增加了严重神经发育问题的风险。我们不能排除暴露后数学成绩较低的可能性，这与瑞典的一份报告类似。
