104
11 Health Effects of Nuclear Weapons
travel the furthest downwind. Thus, the concentration of radioactivity is expected to
drop steadily along the downwind axis of the plume as one travels away from the
site of the explosion. If there are multiple plumes, this same process will occur in
each; if the winds are variable and changing direction frequently then this will help
to further scatter and diminish contamination by the time it reaches the ground.
Radiation dose rates along the centerline of the plume might be as high as a few
to several tens of Gy hr
−1 initially, a km or so from the explosion, dropping to a few
Gy hr
−1 several km downwind and to tens or hundreds of mGy hr
−1 even further
away. All of these dose rates will drop rapidly with time according to the 7–10 Rule
discussed in Chap. 9. Although radiation dose rates in the plume will be dangerously
high in the first few hours following detonation, within one or two days they will
drop to the point at which it will likely be safe to evacuate.
Knowing the amount of radioactivity produced per kt of yield, the amount of
material produced by a blast of a given yield, the distribution of particle sizes (and
subsequent distance traveled), and other relevant factors it is possible to determine the
area that can be contaminated to produce dose rates of various orders of magnitude.
According to a 2005 report by the National Academies of Science [7] “The area
covered by the associated dose that would cause at least a 50 percent probability of
fatality is roughly 2.6 square kilometers per kiloton, assuming that people are in the
open and exposed for just the first day after the burst.” Thus, we can estimate that
26 km
2 would be contaminated to this level in the aftermath of the 10 kt detonation
we have been assuming, with larger areas contaminated to lesser levels.
These high radiation levels make it important for everybody in the city attacked,
including emergency responders, to find shelter immediately and to remain sheltered
until they can verify that it is safe to go outdoors. In the case of emergency responders
this can be determined with their own radiation instruments; members of the public
should shelter until they are told that conditions are safe in their location—this
information can be delivered in person by emergency response or public health
personnel or this information can be conveyed by television, radio, or internet. Other
immediate response actions will be discussed in detail in Chaps. 15–19.
11.4 Non-radiological Risks in the Vicinity
of the Detonation
While the radiological health effects are the ones that worry the public the most, the
non-radiological health effects can be equally significant—and more so in locations
outside the radius of the mass fires and structural collapse.
11 Health Effects of Nuclear Weapons
travel the furthest downwind. Thus, the concentration of radioactivity is expected to
drop steadily along the downwind axis of the plume as one travels away from the
site of the explosion. If there are multiple plumes, this same process will occur in
each; if the winds are variable and changing direction frequently then this will help
to further scatter and diminish contamination by the time it reaches the ground.
Radiation dose rates along the centerline of the plume might be as high as a few
to several tens of Gy hr
−1 initially, a km or so from the explosion, dropping to a few
Gy hr
−1 several km downwind and to tens or hundreds of mGy hr
−1 even further
away. All of these dose rates will drop rapidly with time according to the 7–10 Rule
discussed in Chap. 9. Although radiation dose rates in the plume will be dangerously
high in the first few hours following detonation, within one or two days they will
drop to the point at which it will likely be safe to evacuate.
Knowing the amount of radioactivity produced per kt of yield, the amount of
material produced by a blast of a given yield, the distribution of particle sizes (and
subsequent distance traveled), and other relevant factors it is possible to determine the
area that can be contaminated to produce dose rates of various orders of magnitude.
According to a 2005 report by the National Academies of Science [7] “The area
covered by the associated dose that would cause at least a 50 percent probability of
fatality is roughly 2.6 square kilometers per kiloton, assuming that people are in the
open and exposed for just the first day after the burst.” Thus, we can estimate that
26 km
2 would be contaminated to this level in the aftermath of the 10 kt detonation
we have been assuming, with larger areas contaminated to lesser levels.
These high radiation levels make it important for everybody in the city attacked,
including emergency responders, to find shelter immediately and to remain sheltered
until they can verify that it is safe to go outdoors. In the case of emergency responders
this can be determined with their own radiation instruments; members of the public
should shelter until they are told that conditions are safe in their location—this
information can be delivered in person by emergency response or public health
personnel or this information can be conveyed by television, radio, or internet. Other
immediate response actions will be discussed in detail in Chaps. 15–19.
11.4 Non-radiological Risks in the Vicinity
of the Detonation
While the radiological health effects are the ones that worry the public the most, the
non-radiological health effects can be equally significant—and more so in locations
outside the radius of the mass fires and structural collapse.