When the nukes go off… - By M V Ramana Back   Home  
A hypothetical study by M V Ramana shows the terrible the consequences of a nuclear bomb being dropped on Mumbai. The study was carried out for the International Physicians for Prevention of Nuclear War
The nuclear tests by India and Pakistan in May 1998 signalled the beginning of a dangerous new era in South Asia. Nuclear war in this part of the world that is home to well over a billion people would be catastrophic. Nor would the effects of the war be limited to just the region. Long-term radioactive fallout respects neither spatial nor temporal boundaries…

The leading causes of casualties following a nuclear explosion are:
  • Thermal (heat) radiation and resulting large-scale firestorms that could cause burns and other severe injuries;
  • Shock waves and accompanying high-speed winds that could crush people or throw them aroun
  • Prompt radiation and radioactive fallout that could cause radiation sickness"
The study estimates the deaths as numbered deaths would range between 160,000 and 866,000 for a 15 kiloton explosion- approximately the same destructive power as the weapon dropped on Hiroshima in 1945… A 150 kiloton weapon-typical of more hydrogen bombs could cause somewhere between 736,000 and 8,660,000 deaths.

While the study does not include the long-term effects like cancers that would afflict thousands of people in the following years or genetic mutations that could affect future generations, it gives immense estimates and evidence as far as technical details are concerned.

The bomb dropped on Hiroshima destroyed a considerable portion of the city and caused 150,000 deaths. Among the survivors, thousands have been suffering from various illnesses caused by exposure to radiation. The consequences of even a small nuclear explosion are so horrendous that it should be clear to anyone that nuclear weapons are genocidal in their very nature and should have no place in civilized society.



The first mechanical effect of the shock wave on any person or object in its path is a forceful blow from the instantaneous pressure jump in the front. This is followed immediately by the crushing effect of blast overpressure and a high velocity wind. Besides the crushing effects and the wind, a third cause of damage due to blast, besides static overpressure and the wind are "missiles". Such missiles could result from debris or objects such as poles, cars, and so on, in the path of the blast wave. The velocity of such missiles could be substantial and can be faster than the blast wave itself.

When it speaks of the affected buildings, the study warns that light housing, such as huts and shacks can be destroyed at 5 psi (terminology used for determining strength and force of nuclear weapon) or more. Wooden frame houses and brick houses can be destroyed at overpressures of 10 psi or more. Reinforced concrete buildings can withstand larger overpressures of up to 20 psi. A high-rise building with a steel frame (of which Delhi and Bombay boast of maximum in number) may require up to 100 psi for the frame to collapse. But the study also warns that even in these buildings the frames at times can buckle at overpressures as low as 5-10 psi. Thus people in these buildings will either be killed or hurt by the debris.

The blast wave also crushes human bodies, damaging the lungs and circulatory systems. Lungs will be damaged by about 20 psi of overpressure. Eardrums rupture around the same level of overpressure.

Damage Overpressure (in psi)
Light housing destroyed 5
Brick housing/ commercial buildings destroyed 10
Reinforced concrete structures destroyed 20 20
Severe lungs damage/ eardrum rupture in humans 20-30
Death of humans 40-100
Shallow buried structures destroyed 45-280


Primary and secondary burns can be important causes of deaths in the immediate aftermath of a nuclear explosion.

Medical effects of burns:

Level of burns Medical effect
First Mildest form of burn. Immediate pain followed by redness of affected area. Will heal without scar formation

Upper and intermediate layers of skin killed. Blisters and swelling develop, accompanied by persistent pain. Extensive burns require specialized treatment in sterile conditions. Healing over several weeks, leaving scarring
Third Full thickness of skin and some underlying tissue is charred. Skin is red or charred. Severe pain from edges of burns. Burns over 2 inches in diameter will heal only after extended treatment including skin grafting. Untreated victim may die of shock if over 20% of the body is affected

Within the course of the explosion, depending on the weather, these fires could start coalesce and form super-fires. The devastation caused by such firestorms can hardly be overstated.

Bombay as an example

Mumbai is India's largest financial and industrial centre, is a big naval and commercial port and has a large atomic research centre nearby.

The study assumes that the attack happens on a clear day and the weapon used is a fission bomb with a yield of 15 kilotons to be exploded at a height of 600 metres.

"With such a small yield, it is not possible to destroy the entire city. The precise location of the attack determines which region of Bombay is destroyed. For example, an attack in the Fort area, centred around Hutama Chowk, could destroy large parts of the financial district as well as the secretariat. Likewise, an attack centred around the Chembur area or the area near Parel and Sewri would result in the destruction of a large number of industries, in the latter case, the attack could also lead to damage to the Mazagaoin docks, whereas in the former case, it could lead to some damage to the Bhabha Atomic Research Centre complex, India's largest nuclear research facility, in Trombay. There are also very densely populated areas like Dharavi; if the explosion is targeted in this area, the number of casualties will be very large."


"Many of the buildings in Mumbai, especially the older ones, are poorly constructed. Every year, several hundred collapse by themselves, especially during the rainy season. Many of these would not even withstand the nominal 10-20 psi values used here."

Escaping a firestorm in Mumbai: Chances, very low

In Mumbai, houses in slum areas, where about 40% of the population lives, are often built with inflammable materials. However, these are low-rise structures. In richer areas, houses are often constructed with brick or concrete, which are less inflammable. However, such houses typically have greater amounts of furniture, clothes, carpets and so on, all of which are likely to burn. Many houses then would contain gas cylinders that are likely to explode and burn.

Casualty estimates for Mumbai

The average population density of Bombay is about 23,000 people/km^2. Therefore deaths can be anywhere between 1.6-2 lakhs (1 lakh= 100,000). However, the more crowded areas of Bombay have population densities exceeding 100,000 people/km^2. Therefore, the number of deaths could easily be as high as 6.9 to 8.6 lakhs. It is clear that about 150,000 to 800,000 people will die within the first few months after the attack. In addition, somewhere between 130,000 to 2,100,000 people will be injured.

Medical facilities that could be of possible help to the survivors are likely to be destroyed, or otherwise damaged, during the attack. The number of hospitals and physicians as a proportion of the population in Mumbai is extremely limited to begin with. Hence, it is extremely likely that the injured, estimated to be between 1.3 and 2.1 lakh, will not receive any medical treatment to help them survive.

An attack, if it is carried out by air, is likely to be during the day. Hence many people that arrive in Bombay everyday from places as far away as Pune to work in Bombay will also be killed or injured. Second, casualties from fallout effects have not been included in the estimates. Since fallout, even if present only in small quantities, can spread out to large regions and cause local hot spots, this is potentially important.

Third, there are a large number of industries in Mumbai and its vicinity is home to several mills. India's highest concentration of chemical industries is in the Trans-Thane creek area; this area has over 2,000 factories. These could cause additional fires, explosions, and spreading of toxic substances and consequently more deaths.

"The immense scale of these effects, and that too resulting from just a single fission weapon with a low yield, should make it clear that the possible use of such weapons would lead to a major catastrophe. The only guarantee that such a tragedy would never occur is complete elimination of nuclear weapons, both from the region and from the world, and the means to manufacture them," concludes the study.
Published in Indian portel Tehelka, dated June 07, 2002