Working Paper: NBER ID: w13347
Authors: Douglas Almond; Lena Edlund; Märten Palme
Abstract: Japanese atomic bomb survivors irradiated 8-25 weeks after ovulation subsequently suffered reduced IQ [Otake and Schull, 1998]. Whether these findings generalize to low doses (less than 10 mGy) has not been established. This paper exploits the natural experiment generated by the Chernobyl nuclear accident in April 1986, which caused a spike in radiation levels in Sweden. In a comprehensive data set of 562,637 Swedes born 1983-1988, we find that the cohort in utero during the Chernobyl accident had worse school outcomes than adjacent birth cohorts, and this deterioration was largest for those exposed approximately 8-25 weeks post conception. Moreover, we find larger damage among students born in regions that received more fallout: students from the eight most affected municipalities were 3.6 percentage points less likely to qualify to high school as a result of the fallout. Our findings suggest that fetal exposure to ionizing radiation damages cognitive ability at radiation levels previously considered safe.
Keywords: Chernobyl; Radiation Exposure; Cognitive Development; School Outcomes; Sweden
JEL Codes: I18; I20; Q48; Q53; J24
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| Fetal exposure to ionizing radiation (I19) | damages cognitive ability (D91) |
| Exposure during 8-25 weeks post-conception (J13) | worse school outcomes (I24) |
| Prenatal exposure to radioactive fallout from the Chernobyl accident (I12) | worse school outcomes (I24) |
| Children in utero during Chernobyl accident (J13) | lower likelihood of qualifying for high school (I24) |
| Higher fallout exposure (Y50) | worse school outcomes (I24) |