In the first post of this series, I described what happens to the human body at ground zero of a 10 to 15-kiloton nuclear detonation: the zone within 800 meters of the hypocenter. There, the thermal pulse delivers over 100 calories per square centimeter to the skin, carbonizing the epidermis and dermis before a single nerve ending can fire a pain signal.

The blast wave, arriving a fraction of a second later with overpressures exceeding 10 psi and winds above 500 kilometers per hour, collapses every structure and turns the debris into projectiles. The initial radiation, exceeding 50 Gray at close range, shatters the DNA of every cell in the body. Three lethal mechanisms delivered almost simultaneously. No one survives unshielded. No burn unit, no trauma surgeon, no field hospital can change the outcome. At ground zero, medicine has nothing to offer except documentation.

This is Part II. One mile. The Moderate Damage (MD) zone, extending from 0.8 to 1.6 kilometers from the hypocenter of a 10 to 15-kiloton detonation. This is where medicine becomes cruel. Not because it is absent, but because the victims survive long enough to need it, and there is no one left to provide it.

The survivors who should not have survived

At one mile from the hypocenter, the thermal fluence drops to approximately 8 to 20 calories per square centimeter. This is no longer enough to carbonize tissue on contact. It is enough to produce second and third-degree burns on all exposed skin within a fraction of a second. The epidermis blisters, separates from the dermis, and in areas of direct exposure the full thickness of the skin is destroyed.

Clothing offers variable protection: dark fabrics absorb more thermal energy and can ignite, while lighter materials may reflect enough to reduce burn depth. In Hiroshima, survivors at this distance bore the thermal imprint of their clothing patterns on their skin, the dark portions of kimono designs seared into the flesh while the light portions left the underlying skin relatively intact.

The eyes, if directed toward the fireball, suffer flash blindness or permanent retinal burns depending on the duration of gaze. Unlike at ground zero, where the entire globe is destroyed, at one mile the retinal burn is focal. A person who happened to glance at the fireball would lose central vision permanently while retaining peripheral sight. A person who was looking away might retain full vision. The difference between blindness and sight at this distance is determined by the direction of a single glance in a fraction of a second.

The blast wave at the inner boundary of the MD zone arrives with an overpressure of approximately 3 to 5 psi and winds of 100 to 200 kilometers per hour. This is not enough to flatten reinforced concrete structures, but it is enough to shatter every window in every building within the zone. And in a modern city, windows are everywhere.

A standard glass pane shatters at approximately 0.5 to 1 psi. At 3 psi, the glass fragments into hundreds of projectiles traveling at velocities sufficient to penetrate human skin, muscle, and in some cases the thoracic or abdominal cavity. Studies of blast injuries from conventional explosions have documented glass fragments embedded in vital organs at distances where the overpressure itself was survivable. At one mile from a nuclear detonation, the glass becomes the weapon. The overpressure is the delivery mechanism.

The FEMA planning guidance for nuclear detonation response identifies the MD zone as the area where the greatest number of salvageable casualties will be found. The majority of those casualties will present with penetrating glass injuries combined with thermal burns. The combination is what kills.

The lethal arithmetic of combined injury

This is where the medicine of nuclear weapons diverges from everything taught in civilian trauma courses. A patient with 30% total body surface area burns, if treated in a modern burn center with fluid resuscitation, wound care, and infection control, has a survival rate exceeding 90%. A patient exposed to 2 Gray of whole-body ionizing radiation, if treated with supportive care and growth factors, has a survival rate exceeding 90%. A patient with both injuries does not get the sum of those odds. The mortality multiplies.

Animal studies and clinical observations from Hiroshima have shown that combined injury can reduce survival to below 50% even when each injury alone would be survivable in more than 90% of cases. The immune system, attacked simultaneously from two directions, collapses.

The mechanism is immunological. Ionizing radiation at doses of 1 to 5 Gray, the range delivered to unshielded individuals at one mile from a 15-kiloton detonation, selectively destroys the most radiosensitive cells in the body: lymphocytes, hematopoietic stem cells, and the rapidly dividing cells of the intestinal epithelium. Within 48 hours, the absolute lymphocyte count begins to fall.

Within one week, the bone marrow’s production of neutrophils, the white blood cells responsible for fighting bacterial infection, declines measurably. Within two weeks, the neutrophil count reaches its nadir. A burn wound is an open portal for bacterial invasion. Under normal circumstances, the immune system mounts an aggressive inflammatory response to contain the infection while the wound granulates and re-epithelializes.

But in a patient whose bone marrow has been damaged by radiation, the neutrophils are not coming. The lymphocytes that coordinate the adaptive immune response are dead or dying. The burn wound becomes a culture medium for bacteria that the body can no longer fight. Sepsis follows. Organ failure follows sepsis. Death follows organ failure.

This is combined injury. Burns that would be survivable become lethal. Radiation doses that would be survivable become lethal. Glass lacerations that would require only sutures become lethal, because the wounds cannot heal in a body whose clotting factors are depleted by a marrow that no longer produces platelets. The Japanese clinicians who treated survivors in Hiroshima and Nagasaki documented this phenomenon extensively: patients whose external wounds appeared manageable deteriorated and died in the second and third week, as the hematological effects of radiation overtook the body’s capacity to repair itself.

The cruelest feature of radiation injury at these doses is the latent period. In the first hours and days after exposure to 1 to 5 Gray, the victim experiences what is called the prodromal syndrome: nausea, vomiting, fatigue, and sometimes diarrhea. These symptoms resolve within 24 to 72 hours. What follows is a period of days to two weeks during which the patient feels well. The nausea is gone. The appetite returns. The burn wounds, if not severe, appear to be stabilizing. The patient may walk, talk, and believe that the worst is over.

This is the latent phase. Clinicians in radiation medicine call it the walking ghost phase. During this apparent recovery, the bone marrow is silently dying. The hematopoietic stem cells, damaged beyond repair by the initial radiation pulse, are failing to divide. The existing blood cells circulating in the body have a finite lifespan. Red blood cells survive approximately 120 days, but platelets survive only 8 to 10 days, and neutrophils only 6 to 8 hours.

As the old cells die and no new ones replace them, the blood counts begin to drop. By day 10 to 14, the patient enters the manifest illness phase: spontaneous hemorrhage from depleted platelets, fever from infections that the absent neutrophils cannot contain, and progressive anemia as the red cell mass declines.

And then the hair falls out. Epilation, the sudden loss of hair in clumps beginning around day 14, became the most feared visible sign in Hiroshima and Nagasaki. The hair follicle, like the bone marrow and the intestinal crypt, contains rapidly dividing cells that are exquisitely sensitive to ionizing radiation. When the hair began to fall, the Japanese physicians learned to recognize it as a death sentence.

Tomonaga documented that survivors who developed epilation had received doses high enough to destroy their bone marrow. A patient who woke up to find hair on the pillow knew, even without a blood count, even without a physician, what was coming.

The gastrointestinal tract suffers in parallel. The mucosal lining of the intestine, particularly the colon, is composed of rapidly dividing epithelial cells that are highly sensitive to ionizing radiation. Tomonaga, in his examination of Nagasaki survivors, documented the destruction of the colonic mucosa: the normal folds that expand the absorptive surface of the large intestine were obliterated, and the mucosal cells that absorb water and nutrients were destroyed.

Without those cells, the colon cannot absorb water. Survivors drank desperately but could not quench their thirst. The water passed through the damaged intestine without being absorbed, worsening the diarrhea, accelerating the dehydration, creating a cycle that no amount of drinking could break.

At doses of 2 to 5 Gray, the damage to the intestinal epithelium compounds the hematopoietic failure. The gut barrier, which normally prevents the trillions of bacteria residing in the intestinal lumen from entering the bloodstream, becomes permeable. Bacteria translocate across the damaged mucosa into the portal circulation. In a patient whose neutrophil count is already collapsing from marrow failure, this bacterial invasion meets no resistance. The result is septicemia: bacteria in the blood, uncontrolled fever, circulatory collapse.

The patient who appeared to be recovering now develops intractable diarrhea, dehydration, and electrolyte imbalances that cannot be corrected without intravenous fluids that do not exist. In a hospital with blood banks, antibiotics, antifungals, and laminar flow isolation rooms, some of these patients can be saved. In the aftermath of a nuclear detonation, there are no such hospitals.

In Hiroshima, approximately 90% of physicians and nurses were killed or incapacitated by the blast. The late Dr. Reyna Durón and I documented this catastrophic loss of medical capacity in a peer-reviewed article published in the Journal of Preventive Medicine and Public Health: the infrastructure of care is destroyed at the same moment the demand for care becomes infinite.

What this means in a modern city

The MD zone of a 15-kiloton detonation in a dense Middle Eastern city, whether Tel Aviv, Tehran, or any urban center in the region, would encompass an area of approximately 5 to 8 square kilometers. Within that area, tens of thousands of people would survive the initial blast with injuries that are, in principle, treatable. Burns. Lacerations. Fractures. Embedded glass. Blast lung. Ruptured eardrums. Each of these, in isolation, is a manageable clinical problem.

But none of them would occur in isolation. Every patient would also carry an invisible injury: a dose of ionizing radiation between 1 and 5 Gray that they cannot feel, that produces no visible wound, and that will not manifest clinically for one to three weeks. By the time the radiation sickness declares itself, the window for meaningful intervention will have closed. The antibiotics will have run out. The blood products will not exist. The burn centers will be rubble.

The FEMA planning guidance designates the MD zone as the area where triage efforts should be concentrated, because it contains the largest population of potentially salvageable victims. This is a rational assessment for a single detonation in a country with intact infrastructure beyond the blast radius. In a regional conflict, where multiple detonations are possible and where the surrounding medical infrastructure may itself be compromised, the word “salvageable” loses its clinical meaning.

The shadow that does not end

For those who survive the burns, the blast, the glass, the bone marrow collapse, the intestinal destruction, and the infections, the ordeal does not end. It transforms. Ionizing radiation damages DNA in ways that may not manifest for years or decades. The double-strand breaks that were not lethal enough to kill the cell outright can be repaired incorrectly, producing mutations that accumulate silently in the surviving tissue.

Tomonaga documented the long arc of this damage in the hibakusha: leukemia appeared first, beginning around 1949, just four years after the bombings, with incidence peaking between five and ten years post-exposure. Then came the solid cancers, thyroid, breast, lung, stomach, colon, bladder, ovary, rising steadily through the 1960s and continuing for the rest of the survivors’ lives. The Radiation Effects Research Foundation has followed this cohort for nearly eighty years, and the excess cancer risk has never returned to zero.

In Hiroshima and Nagasaki, many of these cancers were eventually diagnosed and treated. Japan rebuilt its hospitals. Oncologists, surgeons, and radiotherapists were trained. Chemotherapy protocols were developed. The hibakusha had access, imperfect but real, to a functioning medical system.

In a future nuclear conflict, that assumption collapses. A regional nuclear exchange would destroy hospitals, pharmaceutical supply chains, and the personnel trained to operate them. The late Dr. Reyna Durón and I warned precisely of this in our article in the Journal of Preventive Medicine and Public Health: the availability of medications for cancer, diabetes, cardiovascular disease, and other chronic conditions would be severely compromised by a global shortage of medicines, and vaccination and public health programs would cease to exist.

A survivor of the MD zone who develops leukemia five years after the detonation may find that there is no oncologist to diagnose it, no laboratory to confirm it, and no chemotherapy to treat it. The radiation planted a seed. The destroyed medical infrastructure ensures it will grow unopposed. The scale of devastation determines whether that failure is local, regional, or global.

And for those who survive the cancer, or who never develop it, the body carries its own archive of the detonation. The burn wounds that healed in the weeks after the blast do not heal normally. Ionizing radiation disrupts the orderly process of wound repair, and the scar tissue that forms is often hypertrophic: thick, raised, disfiguring keloids that spread beyond the original burn margins and continue to grow for months or years.

In Hiroshima, female survivors with keloid scars on their faces, necks, and arms were systematically rejected as marriage candidates. The keloids marked them. They were visible proof of proximity to the bomb, and in a society that feared the hereditary effects of radiation, that mark was enough to condemn a woman to social isolation for the rest of her life.

Some survivors of Hiroshima and Nagasaki later said they wished they had died at the moment of the blast. They meant it. To survive the initial detonation at one mile only to endure third-degree burns without analgesics, bone marrow failure without transfusions, intractable diarrhea without intravenous fluids, hair falling in clumps on the pillow, keloid scars deforming the face, and then years later a leukemia diagnosis with no oncologist and no chemotherapy, this is not survival in any meaningful sense. It is a prolonged execution carried out by the body against itself, using the tools that the bomb left behind in every damaged cell.

Everything described in this series is based on the medical evidence from Hiroshima and Nagasaki, two bombs of 15 and 21 kilotons respectively. The weapons in today’s arsenals are of a different order. The W88 warhead carried on American submarine-launched Trident missiles yields 475 kilotons, more than thirty times Hiroshima, and multiple W88s sit on a single missile, each aimed at a different city. The American B83 gravity bomb, still in active service, has a maximum yield of 1.2 megatons, eighty times the power of Hiroshima. The Soviet Tsar Bomba, tested in 1961 at 50 megatons, was more than 3,300 times more powerful than the weapon that destroyed Hiroshima. It was designed for 100 megatons and was deliberately tested at half its capacity because the bomber crew might not have survived the full yield. No nuclear weapon of this magnitude has ever been detonated over a populated area.

There is no clinical data, no Tomonaga equivalent, no RERF cohort study for a one-megaton detonation in a modern city. The distances described in this article, one mile for the MD zone, three miles for the LD zone, would expand by multiples. The number of walking ghosts would be measured not in thousands but in hundreds of thousands. The medical system would not merely be overwhelmed. It would not exist.

© The Times of Israel (Blogs)