Effects of Nuclear Weapons

Most of what is known about the effects of nuclear weapons on humans comes from the two atomic bombs dropped on the Japanese cities of Hiroshima and Nagasaki in 1945. There is also a lot of information from atmospheric nuclear testing and nuclear accidents. Although there are many different types of nuclear weapon with varying amounts of explosive power, the effects would be the same – except on a different scale.

For example, the bomb that was exploded above Hiroshima was 15 kilotons (that’s the equivalent of 15,000 tons of TNT). The Nagasaki bomb was around 21 kilotons. A single Trident warhead is 100 kiltons. Britain has 180 of these warheads.

It’s important to remember that nuclear weapons are not just big bombs. They do not have the same make up as the sort of terrorist bombs or heavy artillery fire seen regularly on the television news. So what happens when a nuclear weapon explodes?

The effect on the human body is horrific but it’s important for people to know what happens. The temperature of a nuclear explosion is several million degrees centigrade. The explosion creates a fireball of white heat. On exploding, intense heat and radiation is released in winds of around 1000 mph. This also creates huge pressure on the surrounding air. The mushroom cloud effect is produced by the powerful updrafts lifting debris from the ground up into the air. The top of the cloud can be several kilometres wide.

At Hiroshima, within a radius of half a mile, the only remains of most of the people caught in the open were their shadows burnt into stone. That’s quite difficult to imagine. Nothing left of you but a shadow on the floor. If you are in a building or otherwise shielded you will be indirectly killed by the blast and heat effects as buildings collapse and all inflammable materials burst into flames.

Under these extreme conditions, the human body melts. Eyeballs, facial features, internal organs all melt. However, it could be argued that those who die immediately would be the lucky ones. Those not in the immediate area of destruction would suffer from non-survivable burns, would be blinded, bleeding from glass splinters and would have suffered terrible internal injuries. Even those with possibly survivable injuries would die since almost all rescue and medical services would have been destroyed and personnel killed. Most casualties would at best receive minimal treatment. The death rate among the seriously injured would approach 100%. The best they could hope for would be to die in as little pain as possible.

As you would expect, your chances of survival are better the further away you are from the blast. However, survivors would soon suffer the consequences of radioactive fallout. The effects of the fallout vary. Exposure to high levels of radiation can cause bleeding from the mouth and gums, gangrenous ulcers, hair loss, internal bleeding and haemorrhagic diarrhoea, vomiting, fever, delirium and terminal coma. There is no effective treatment and you would die within days.

Although the chances of surviving for longer are better following a lower level of exposure, the death rate is still very high. The longer term effects include foetuses in the early stages of pregnancy being born with deformities and disabilities, damage to the immune system and major scars.

Even if you do survive in the short-term, there is a serious risk that you will develop cancer. There is also a risk that your children would be more likely to have birth defects or leukaemia and other cancers, though this has not been reported in the children of Hiroshima and Nagasaki survivors.

The amount of fallout depends on what sort of nuclear explosion occurred. For example, at Hiroshima it was an ‘air-burst’. That means that the bomb was exploded in the air above the city. An air-burst increases the effects from the heat and blast. A ‘ground-burst’, where the bomb is exploded on the ground, causes much larger quantities of radioactive debris to be sucked up into the atmosphere.

The area covered by fall-out is determined by wind speed and direction. The heavier particles of radioactive material will fall in the immediate or close vicinity. Finer particles will be wind blown over longer distances before they descend. Very fine particles may be blown very long distances before they combine with water vapour and fall as radioactive rain. This was shown graphically in the aftermath of the explosion at the nuclear power plant at Chernobyl, Ukraine, in 1986. Although the radiation from such a plant is different from that released by a bomb, radioactive rain fell across much of northern Europe, reaching as far as north Wales, Scotland and Cumbria. North Wales is over 1000 miles from Chernobyl.