Radiation Dosages Received Per Distance From Hypocenters
The physiological effects to humans from the atomic bombings of Hiroshima and Nagasaki are directly related to the distance individuals were from the hypocenters of the bombs at the time of the attacks. Figure 1 is a graph comparing casualties based upon varying distances from the Hiroshima hypocenter.
Individuals located at or near the hypocenters of the explosions were subject to detrimental thermal and blast rays and received radiation doses incompatible with life (10 Sv or more). More than 90% of all individuals located at or near the hypocenters perished. Those receiving dosages around 3 Sv died within approximately 60 days; these individuals were located from 2.7 to 3.1 m distance from the hypocenters or were in their homes within 1 km of the hypocenters (RERF, 2006). People located beyond 2 km from the hypocenters received 0.1 Sv and effects at this point are not considered acute. At distances greater than 3 km from the hypocenters, radiation dosages approximated 0.002 Sv. This would be about the same amount of radiation an average person would be exposed to in a year.
Health Symptoms From Radiation Received Per Dosages
Table 1 provides information regarding the early physiological symptoms experienced per radiation dosage exposure (RERF, 2006). Note: Sv = sievert, a unit used to measure radiation dosage. For more information on radiation dosages, click the following link: http://www.ccohs.ca
ionizing.html. Late effects (occurring from several months to several years after the events) from exposure to radiation experienced by individuals present at the Hiroshima and Nagasaki bombings include excess cancer risks, especially leukemia (onset 5-10 years after exposure); an increased incidence of benign tumor formation; an increased occurrence of digestive, liver and respiratory diseases; remarkably high cholesterol levels; white blood cell chromosomal abnormalities; immunodeficiency; and early onset geriatric disorders (RERF, 2006). Table 2 (RERF, 2006) provides information pertaining to the cancer deaths per dose range among atomic bomb victims over a 40 year period following the attacks.