The horrors of a nuclear war

In the midst of a concerted effort to sanitise the image of nuclear weapons instead of recognising them as weapons of mass destruction, an account of the grim experiences of Hiroshima and Nagasaki.

T. JAYARAMAN

But the inventors
of that ultimate weapon
which, on the dark night of the sixth
of August, Nineteen Forty-Five,
danced the dance of death in
Hiroshima-Nagasaki
and took the sacrifice of over two
hundred thousand people,
crippled thousands of people for life.

Did they, for a second even,
get the feeling that what they had
done
was not right?
If so, then time will not put them in
the dock,
but if not then history will never
forgive them.

- from the poem "Hiroshima ki Peedha" (The Pain of Hiroshima) by Atal Behari Vajpayee, published in his collection, Meri Ikyavan Kavitaein (My Fifty-One Poems), Kitab Ghar, New Delhi, 1995.

"Did I explore space to enhance science or did I provide weapons of destruction?"

- from the poem "Tumult" (originally in Tamil) by A.P.J. Abdul Kalam, quoted by John F. Burns, in an article in The New York Times on May 20, 1998.

IN those moments when Prime Minister Atal Behari Vajpayee's soul is not one with the Sangh Parivar, and Dr. A.P.J. Abdul Kalam's scientific rationality or moral sensitivity is not overtaken by jingoism, it is clear that the two proponents of India's nuclear weapon state status recognise nuclear weapons for what they are: weapons of mass destruction. However, there has been little evidence of such moments in the aftermath of Pokhran-II.

In a language that is in vogue among the pro-nuclear test political figures, leading atomic energy and defence scientists and instant "experts" of an assorted variety, bombs are merely "devices", and nuclear weapons are merely "weapons of deterrence". In the midst of this concerted effort to sanitise nuclear weapons, it seems worthwhile to recall the grim experiences of Hiroshima and Nagasaki. The knowledge of that tragedy has, over the past 50 years, impelled millions of people to protest against nuclear weapons and take up the cause of nuclear disarmament.

Weapons of mass destruction are generally those that affect soldier and civilian alike, but are mostly targeted at the second category. These weapons can be of the nuclear, chemical or biological kind.

Although chemical weapons have been used, their use has generally been as an extension or modification of conventional weapons, without the worst being seen in action. It is only the nuclear weapons that have been used in a form that is not substantially different in its effects from the modern variants, apart from questions of scale. Despite the protests of some of the scientists who worked on developing them, the United States decided to use the first nuclear weapons on the Japanese cities of Hiroshima and Nagasaki towards the end of Second World War.

GAMMA
A few hours after "Little Boy" was dropped on Hiroshima on August 6, 1945. The nuclear bomb, which had a yield of 15 kilotons, killed 200,000 of the city's 350,000 people.

Hiroshima and Nagasaki were bombed on August 6 and 9, 1945, respectively. The bomb that was dropped on Hiroshima was of untested design and used 700 gm of enriched uranium as fissile material. By 1950, it had caused the deaths of over 200,000 of the 350,000 people who were estimated to have been present in the city on that day. The bomb that was dropped on Nagasaki used plutonium and eventually killed 140,000 of the estimated 270,000 people present in Nagasaki at that time. "Little Boy", the bomb that was dropped on Hiroshima, had a yield of 15 kilotons equivalent of TNT, while "Fat Man", that was dropped on Nagasaki, had a yield of 21 kilotons. The results were there for all to see - death and devastation on a scale hitherto unknown to humankind.

These bombs, as predicted by physicist Hans Bethe, first generated an enormous fireball. A major fraction of the release of energy from a nuclear explosion is in the form of electromagnetic radiation ranging over the entire spectrum - from X-rays to thermal radiation. The X-rays, absorbed by the medium surrounding the exploding weapon, heat the atmospheric gases to create an expanding bubble of high temperature - the fireball. (In a 1-megaton explosion, the X-rays can penetrate up to 3 km before they are fully absorbed.) The fireball radiates both heat and light. Surprisingly, the light did not cause too much damage since not many people were looking directly at the sky at the time of the explosion. Most of the damage was temporary and lasted from a few hours to a few days.

A nuclear weapon explosion also generates intense currents and electromagnetic fields (known as an electromagnetic pulse) that does not damage living organisms but causes severe damage to electronic and electrical equipment. In the case of a modern city, this would lead to immediate and total collapse of communication.

In an atmospheric nuclear weapon explosion, it is the thermal radiation combined with the shock wave that follows that creates the maximum damage. The thermal radiation is intense in a zone around the hypocentre (the point on the ground directly below the atmospheric explosion) whose size is related to the yield of the explosion. The temperature was 600 ^oC at a distance of 1 km from the Hiroshima hypocentre and 1.5 km from the Nagasaki hypocentre. The intensity of the heat was estimated to be seven times that required to burn black paper. Those who were unshielded in this zone suffered from severe third-degree burns that lead to death within a week. The effects of thermal radiation can be attenuated by water and dust particles in the air. Unfortunately, August 6, 1945, was a fine, clear day in Hiroshima. There were instances of fourth- and fifth-degree burns closer to the hypocentre, with even the tissue below the skin, such as muscle, being destroyed. Closer to ground zero, the temperature was 15 times that which can cause third-degree burns. These thermal intensities are sufficient to flash exposed flesh to steam, leaving the bones bare. The third-degree burn zone can extend beyond 10 km for a 1-megaton explosion.

The thermal flash can cause a spontaneous combustion of flammable objects and structures of wood, trees and so on or their charring, but it does not lead to much self-sustained combustion. What really set off the fires in Hiroshima and Nagasaki was the blast effect of the shock wave that followed. The shock wave begins near ground zero with speeds close to 100 times that of sound. In Nagasaki, this generated winds at over 1,500 km per hour close to ground zero, while 3 km away, it was over 100 km per hour. The blast wave destroys buildings and other structures, rendering them vulnerable to damage by fire. The fire is usually begun by heating appliances, kitchen fires and the like and is aided considerably by the thermal wave that has just passed. Materials scattered by the blast help the fire spread. In Hiroshima, the fires began 20 minutes after the explosion, and built up into an intense one, with strong winds blowing into the fire area (known technically as a firestorm), with temperatures of up to several hundred degrees. At Nagasaki, it was a slow-starting, less intense fire (a conflagration), which lasted for five hours.

The blast is itself a significant source of damage. The strength of the shock wave is measured in terms of the difference between the pressure immediately behind the shock wave front and the ambient pressure (referred to as overpressure) which tapers off as one moves away from the hypocentre. (For an overview of blast effects from ground zero outward, see box on Page 93.) An overpressure of 0.35 kg per sq cm (5 psi) is sufficient to flatten a city and cause considerable fatalities. A hurricane-speed wind is generated with speeds upwards of 180 km per hour. Human beings are killed either by hurtling objects or from impact on hitting walls and other obstacles. Most buildings in the zone collapse. This overpressure zone extends beyond 12 km for 1-megaton blasts.

This kind of devastation came upon Hiroshima and Nagasaki without warning. The civil defence system was immediately destroyed and those who survived with serious injuries soon turned into fatalities. Fire-fighting was rendered impossible.

To a large extent, radiation is not a separate danger immediately after the blast. The range where radiation effects are lethal are equally, if not more, dangerous for thermal and blast effects. However, it is the radioactive contamination that is the chief cause of delayed fatalities.

The contaminants are the products of the nuclear reactions in the bomb and the effect of the products on the elements in the environment. The maximum danger comes from radioactive materials of a wide variety that settle on the ground. This condition is called the "fallout". In fact, the current generation of weapons, with 200 to 750 kiloton yields, will cause a greater fallout than the megaton-range weapons of the 1950s and the 1960s.

Radioactivity causes two kinds of effects - acute and latent. Acute effects, which result from rapid exposure, show up within a few weeks, while latent effects, which result from prolonged exposure to relatively lower levels of radiation, become noticeable over a longer period of time. Typically, acute effects are from the fallout in the immediate aftermath of the explosion, while latent effects come from subsequent exposure. The acute effects at Hiroshima and Nagasaki affected not only those who were in the cities at the time of the explosion, but also those who entered them later, even 100 hours after the blasts, and went near the hypocentre.

PAN-ASIA PHOTO NEWS
A view of what was Hiroshima's main business and industrial centre, shortly after the bomb was dropped. The bomb destroyed 60,000 of the city's buildings in a matter of seconds.

Acute radiation sickness from severe exposure resulted in death within two weeks; those who were exposed to a lesser degree died six to eight weeks later. As for latent effects, the incidence of cancer, particularly leukaemia, increased in the period between 1950 and 1953. There was an increase in the number of people who suffered from other kinds of cancer later.

Radiation mostly affects those cells in the human body that replicate most rapidly. Children and infants are thus more sensitive to radiation injury than adults. It is, however, foetuses that are the most vulnerable. According to the Radiation Effects Research Foundation at Hiroshima and Nagasaki, unborn children who were exposed to radiation suffer from intelligence quotient impairment, mental retardation and poor physical growth.

There is now an enormous amount of literature available on the short-term and long-term effects of radioactive contamination, based not only on the data available from Hiroshima and Nagasaki, but also from areas where people have been unwittingly exposed to radiation. However, conclusive results about the extent of genetic damage caused due to radiation exposure at Hiroshima and Nagasaki can be drawn only after another generation is studied.

Nuclear weapons also cause long-term damage to the environment. A full-scale global nuclear war can lead to long-term climatic changes caused by the soot thrown up by burning cities, a phenomenon referred to as "nuclear winter". The soil and the ecosystem will also be affected. Today, there is no residual radioactivity in the cities of Hiroshima or Nagasaki that witnessed single explosions. However, it may be different with explosions that are much closer to the ground, or with multiple explosions, both of which can lead to increased fallout. The Chernobyl disaster provides valuable information in this regard.

WHAT are the lessons that Hiroshima and Nagasaki provide for the subcontinent? Any such confrontation here would have even more disastrous consequences. The combination of thermal and blast effects would be lethal in the South Asian cities of today. Buildings would be razed well beyond the 0.35-kg-per-sq-cm zone. In all probability, the blast effects would be seen farther out, with little to impede the shock wave. The post-nuclear exchange scenario would be one of unimaginable chaos.

Even 50 years after Hiroshima and Nagasaki, no credible scheme of civil defence to help cope with a nuclear confrontation exists. Despite wild claims from some quarters in the Department of Atomic Energy (see box, at right), there is no way that India or Pakistan can build shelters for its population, when even countries such as the U.S. have given up the idea.

With all this knowledge, and much more, readily available, the current celebration of nuclear weapon tests in India and Pakistan, especially among the educated elite, seems grotesque. Small wonder then that Dr. Mariko Kitano, an Islamic scholar from the Osaka University and grand-daughter of a Nagasaki survivor, was disgusted over the celebrations she witnessed in Islamabad soon after Pakistan conducted nuclear tests. In an angry letter to a Pakistani newspaper, she described the scars she bears of "that living hell" in her "deformed feet, one eye that cannot see and a left hand that only lies motionless at my side." "I am sickened to my stomach," she wrote, "at the sight of these jubilant faces celebrating Pakistan's nuclear test." "These are faces of unashamed ignorance. These are faces that have never even given a thought, let alone seen, the evil that is manifested in nuclear arms."

These are words that could as well be directed at those in India who view anti-nuclear weapon campaigners as being unpatriotic.

This year, Hiroshima Day in August will not only be an occasion to recall the meaning of the tragic experience of those cities, but also an important opportunity for all peace-loving sections of the public to gather together and resist nuclear weaponisation in South Asia.

Note: The literature on Hiroshima and Nagasaki and on the effects of nuclear weapons is a vast one. This article is based on two useful sources. The first one is a book titled The Meaning of Hiroshima and Nagasaki written by N.D. Jayaprakash and published by Delhi Science Forum and Kerala Sastra Sahitya Parishad, New Delhi, 1990. The second source is the Web site High Energy Weapons Archive at http://www.fas.org/nuke/hew, especially the section titled 'Nuclear Weapons: Frequently Asked Questions' by Carey Sublette.

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