Table 1.

Atomic bomb survivors (n.s. = not specified).

Reference	Study Population (Location)	Sample Size	Type of Exposure	Age at Exposure	Brain Dose	Outcome	Age at Outcome Measurement
Wood, Johnson et al., 1967 [4]	atomic bomb survivors (Japan)	183	γ-rays and neutrons	in-utero	≤4 Gy	small head size, mental retardation	n.s.
Otake, Schull; 1984 [2]	atomic bomb survivors (Japan)	n.s.	γ-rays and neutrons	in-utero	≤4 Gy	forebrain damage, mental retardation	n.s.
Schull, Otake; 1986 [3]	atomic bomb survivors (Japan)	n.s.	γ-rays and neutrons	in-utero	≤4 Gy	mental retardation	n.s.
Otake, Schull; 1991 [9]	atomic bomb survivors (Japan)	1673	γ-rays and neutrons	in-utero	0.6–1.4 Gy	IQ decline, lower school performance	10–11 years
Yoshimaru, Otake et al., 1991 [8]	atomic bomb survivors (Japan)	929	γ-rays and neutrons	in-utero	≤4 Gy	lower school performance	n.s.
Ikenoue, Ikeda et al., 1993 [6]	atomic bomb survivors (Japan)	929	γ-rays and neutrons	in-utero	≤4 Gy	lower school performance	n.s.
Otake, Schull; 1993 [7]	atomic bomb survivors (Japan)	1473	γ-rays and neutrons	in-utero	≤4 Gy	small head size, mental retardation	9–19 years
Yoshimaru, Otake et al., 1995 [8]	atomic bomb survivors (Japan)	888	γ-rays and neutrons	in-utero	≤4 Gy	IQ decline, mental retardation	15–16 years
Yamada, Sasaki et al., 2002 [10]	atomic bomb survivors (Japan)	3113	γ-rays and neutrons	≥13 years	≤4 Gy	no neurocognitive dysfunction	adulthood
Yamada, Kasagi et al., 2009 [12]	atomic bomb survivors (Japan)	2286	γ-rays and neutrons	≥13 years	≤4 Gy	no increased risk of neurodegeneration	≥60 years
Yamada, Landes et al., 2016 [14]	atomic bomb survivors (Japan)	1844	γ-rays and neutrons	≥13 years	≤4 Gy	no increased risk of neurodegeneration	60–80 years
Yamada, Kato et al., 2021 [13]	atomic bomb survivors (Japan)	303	γ-rays and neutrons	in-utero	≤4 Gy	no increased risk of neurodegeneration	65–70 years
Ishihara, Kato et al., 2022 [11]	atomic bomb survivors (Japan)	469	γ-rays and neutrons	≤12 years	≤4 Gy	no increased risk of neurodegeneration	≥70 years