No statistically significant increase in major birth defects or other untoward pregnancy outcomes was seen among children of survivors. Monitoring of nearly all pregnancies in Hiroshima and Nagasaki began in 1948 and continued for six years. During that period, 76,626 newborn infants were examined by ABCC physicians. When surveillance began, certain dietary staples were rationed in Japan, but ration regulations made special provision for women who were at least 20 weeks pregnant. This supplementary ration registration process enabled the identification of more than 90% of all pregnancies and the subsequent examination of birth outcomes.
Physical examination of newborns during the first two weeks after birth provided information on birth weight, prematurity, sex ratio, neonatal deaths, and major birth defects. Newborn frequencies of untoward pregnancy outcomes, stillbirths, and malformations are shown in Tables 1, 2, and 3 according to parental dose or exposure. The incidence of major birth defects (594 cases or 0.91%) among the 65,431 registered pregnancy terminations for which parents were not biologically related accords well with a large series of contemporary Japanese births at the Tokyo Red Cross Maternity Hospital, where radiation exposure was not involved and overall malformation frequency was 0.92%. No untoward outcome showed any relation to parental radiation dose or exposure.
The most common defects seen at birth were anencephaly, cleft palate, cleft lip with or without cleft palate, club foot, polydactyly (additional finger or toe), and syndactyly (fusion of two or more fingers or toes). These abnormalities accounted for 445 of the 594 (75%) malformed infants in Table 3.
Since many birth defects, especially congenital heart disease, are not detected in the neonatal period, repeat examinations were conducted at age eight to ten months. Among the 18,876 children re-examined at that age, 378 had one or more major birth defect (2.00%), compared with 0.97% within two weeks of birth. Again, there was no evidence of relationships to radiation dose.
Table 1. Untoward pregnancy outcomes (stillbirths, malformations, and neonatal deaths within two weeks of birth) among A-bomb survivors, by parental radiation doses and cases/children examined, 1948-1953
Mother’s weighted dose (Gy) | Father’s weighted dose (Gy) | | <0.01 | 0.01-0.49 | ≥0.50 |
|
<0.01 | 2,257/45,234
(5.0％) | 81/1,614
(5.0％) | 29/506
(5.7％) | | 0.01-0.49 | 260/5,445
(4.8％) | 54/1,171
(4.6％) | 6/133
(4.5％) | | ≥0.50 | 63/1,039
(6.1％) | 3/73
(4.1％) | 7/88
(8.0％) |
|
Table 2. Stillbirths to A-bomb survivors by cases/children examined, 1948-1953
Mother’s exposure conditions | Father’s exposure condition | | Not in cities | Low to middle doses | High doses |
|
Not in cities | 408/31,559
(1.3％) | 72/4,455
(1.6％) | 9/528
(1.7％) | | Low to middle doses | 279/17,452
(1.6％) | 139/7,881
(1.8％) | 13/608
(2.1％) | | High doses | 26/1,656
(1.6％) | 6/457
(1.3％) | 2/144
(1.4％) |
|
Table 3. Malformations diagnosed within two weeks of birth by cases/children examined, 1948-1953
Mother’s exposure conditions | Father’s exposure conditions | | Not in cities | Low to middle doses | High doses |
|
Not in cities | 294/31,904
(0.92％) | 40/4,509
(0.89％) | 6/534
(1.1％) | | Low to middle doses | 144/17,616
(0.82％) | 79/7,970
(0.99％) | 5/614
(0.81％) | | High doses | 19/1,676
(1.1％) | 6/463
(1.3％) | 1/145
(0.7％) |
|
In addition, a clinical health study of about 12,000 individuals was conducted between 2002 and 2006 with a focus on lifestyle diseases, based on the idea that adulthood is when disorders from radiation effects may develop. In this study, possible relationships between parental exposure and a combination of six multifactorial diseases (e.g., diabetes and hypertension) were analyzed, taking into consideration such lifestyle habits as drinking and smoking. The results showed no evidence at this time of increased risk of these multifactorial diseases among the target individuals. However, given that the subjects were still young at the time of the health examinations, with an average age of 48.6, it would be desirable to continue the clinical health study of this fixed cohort.
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FAQs
Birth Defects among the Children of Atomic-bomb Survivors (1948-1954) No statistically significant increase in major birth defects or other untoward pregnancy outcomes was seen among children of survivors. Monitoring of nearly all pregnancies in Hiroshima and Nagasaki began in 1948 and continued for six years.
What were the birth defects after the atomic bomb? ›
In a study of births to related parents who had been exposed to radiation in the bombings of Hiroshima and Nagasaki no consistent effect on the frequency of malformed infants or perinatal deaths was demonstrable.
What are the genetic effects of radiation in atomic bomb survivors and their children? ›
There is, thus far, no indication of genetic effects in the offspring of survivors.
What were the effects of the nuclear bomb on children? ›
There were also great increases in perinatal deaths and cases of microcephaly and retardation in children exposed in utero to the bombs. In the event that there are future generations after a nuclear war, the issue of heritable genetic effects will become important.
What disease was becoming common among the survivors of Hiroshima? ›
Leukaemia was the first cancer to be associated with atomic bomb radiation exposure, with preliminary indications of an excess among the survivors within the first five years after the bombings. An excess of solid cancers became apparent approximately ten years after radiation exposure.
What birth defects did children have from Chernobyl? ›
Long-Term Health Consequences
There has been a 200% increase in birth defects and a 250% increase in congenital birth deformities in children born in the Chernobyl fallout area since 1986. In Belarus, 85% of children are deemed to be Chernobyl victims with genetic changes.
What birth defects are caused by radiation? ›
- Malformations. The risk of malformations is higher in early pregnancy during the organogenesis period (2 to 8 weeks). ...
- Growth restriction. ...
- Mental retardation. ...
- Carcinogenesis. ...
- Genetic mutations.
The International Commission on Radiological Protection ( ICRP ) assumes that the the parental radiation exposure to a single (acute) gonadal dose of 1 gray ( Gy ) leads to one additional severe disease caused by radiation-induced mutations in 500 births. This genetic risk may last for up to two generations.
Can radiation mess up your DNA? ›
Ionizing radiation directly affects DNA structure by inducing DNA breaks, particularly, DSBs. Secondary effects are the generation of reactive oxygen species (ROS) that oxidize proteins and lipids, and also induce several damages to DNA, like generation of abasic sites and single strand breaks (SSB).
What are the long-term effects of radiation on children? ›
Effects on bone development. In young children, radiation can have a significant effect on bone growth and density due to changes in vasculature and chondrocyte populations, leading to side effects such as limb shortening and increased risk of fracture.
It is now generally accepted that children are more sensitive to radiation than adults, specifically with higher relative risk of cancers including leukemia, brain, breast, skin, and thyroid cancers following exposures [4]. In part, this is because of the radiosensitivity of their developing organs and tissues [5,6].
How were school children supposed to survive a nuclear blast? ›
Immediately after one sees the first flash of intense heat and light of the developing nuclear fireball, one should stop, get under some cover and drop/duck to the ground.
What were the side effects of the atomic bomb radiation? ›
The important symptoms reported by the Japanese and observed by American authorities were epilation (lose of hair), petechiae (bleeding into the skin), and other hemorrhagic manifestations, oropharyngeal lesions (inflammation of the mouth and throat), vomiting, diarrhea, and fever.
Were there birth defects from Hiroshima? ›
Of the 500 pregnancies underway when the atomic bomb went off, 21 produced children with severe birth defects, with the highest rates among mothers who were in 8th to 15th week of pregnancy during the blast. That is four times higher than in normal healthy mothers.
What are the nuclear birth defects? ›
The most common defects seen at birth were anencephaly, cleft palate, cleft lip with or without cleft palate, club foot, polydactyly (additional finger or toe), and syndactyly (fusion of two or more fingers or toes).
Are any atomic bomb survivors still alive? ›
Survivors live in all parts of Japan
Hiroshima prefecture has the most survivors, at roughly 114,000, while the next largest population of survivors is in Nagasaki prefecture, with 66,000. In both cases, the proportion of survivors to the general population is nearly one out of 25.
What is a nuclear birth defect? ›
“These birth defects include a reduction in height, severe mental retardation, small head size and impaired brain development, the latter of which may indirectly reduce an individual's intelligence quotient (IQ) and school performance” (Washington State Dept of Health).
What are the genetic disorders in Hiroshima and Nagasaki? ›
Genetic Effects of Radiation in the Offspring of Atomic-Bomb Survivors
| Birth defects (stillbirth, malformation, etc.) | 77,000 |
|---|
| Sex ratio | 141,000 |
| Chromosome aberrations | 16,000 |
| Protein electrophoresis | 24,000 |
| Mortality, cancer incidence (ongoing) | 77,000 |
3 more rowsThe ratio of a single leukemia type to all leukemias was highest for CML in Hiroshima, and the occurrence of CML was thought to be most characteristic to atomic bomb radiation induced leukemia.
What were the effects after the atomic bomb? ›
By the end of 1945, the bombing had killed an estimated 140,000 people in Hiroshima, and a further 74,000 in Nagasaki. In the years that followed, many of the survivors would face leukemia, cancer, or other terrible side effects from the radiation.
