Of the four types of radiation emitted by the nuclear bombs deployed at Hiroshima and Nagasaki,
gamma and neutron rays were the only types strong enough to reach ground and hurt people (see Part 2).
The penetration of ionizing radiation into living human cells can result in cell alteration or death (Bertell, 1985).
Figure 1 is a diagram depicting the process of ionization.
According to the U.S. Nuclear Regulatory Commission (2006), high doses of radiation tend to kill cells.
If enough cells are killed, tissues and organs will suffer immediate damage.
In Nagasaki and Hiroshima this phenomenon became known as Acute Radiation Syndrome
(U.S. Nuclear Regulatory Commission) and resulted in thousands of fatalities.
The rapid invasion of energy into a human cell may also result in the loss of the cell's ability to reproduce itself
or may cause the cell to produce an altered hormone or enzyme from what it would normally produce. These altered or mutated cells
will replicate themselves, eventually resulting in the production of millions of such altered cells. This is known as biological
magnification and causes many chronic diseases normally only associated with the elderly and aging (Bertell, 1985).
An example of one such mutation is the destruction of the cell's ability to rest following cell division. A cell unable to rest will
chaotically and rapidly produce an astronomical number of cells in one location, resulting in a tumor (either benign or malignant)
(Bertell, 1985). Another cellular process affected by ionizing radiation is blood cell production. The rapid production of too many
white blood cells (leukocytes) can cause leukemia, while a rapid proliferation of red blood cells (erythrocytes) often causes
polycythemia vera. For more information on leukemia, access the National Cancer Institute's Leukemia Home Page at
To learn about polycythemia vera, contact the Leukemia and Lymphoma
Society at this link:
Documented Effects of Nagasaki/Hiroshima Bombings on Cellular Processes
Survivors under shelter at the time of the blasts received less radiation exposure
than those out in the open. A medical study conducted on Nagasaki/Hiroshima survivors
who reported being in their homes at the time of the bombings indicated a direct
correlation between dosage received and chromosomal abnormalities. Figure 2 shows
this correlation (Radiation Effects Research Foundation, 2006).
According to Bertell, if radiation penetration affects germ cells (sperm or ovum),
defective offspring may result. Chromosomal diseases resulting from germ cell radiation
include Down's Syndrome, which is caused by failure of chromosomal separation
(nondisjunction). In nondisjunction, one of the daughter cells resulting from cell
division lacks a chromosome and the other daughter cell has an extra chromosome. In the
case of Down's Syndrome, the extra chromosome is at location number 21 (trisomy 21).
An individual with Down's Syndrome is generally moderately to severely retarded
(Schull, 1995). For more information on Down's Syndrome, click on the following link:
http://www.ndss.org/. For an animation of nondisjunction during meiosis resulting in
Down's Syndrome, click here:
According to Schull (1995), in children of survivors of Nagasaki and Hiroshima,
the most commonly encountered sex chromosomal abnormalities were Klinefelter's
Syndrome (a male abnormality resulting from an extra X chromosome) and Turner's
Syndrome (a female abnormality resulting from an extra X chromosome). For more
information on Klinefelter's Syndrome click on the following link:
For more information about
Turner's Syndrome click on this link: