What really happens during a nuclear attack?

The Islamic Republic of Iran has threatened to “raze Tel Aviv and Haifa to the ground” in an unprecedented nuclear attack, as nonproliferation experts warn that the country now has enough enriched uranium for at least one nuclear bomb.

While the exact effects of a nuclear blast on mankind depends on the size of the bomb and how close people are to the explosion, the World Health Organization (WHO) stresses “the use of nuclear weapons will cause human suffering and environmental disturbance on an unprecedented scale.

“In the case of nuclear war, no amount of help from the health profession would be adequate to meet the devastating health needs,” WHO says. 

Most of the information about the impact of nuclear weapons comes from the 1945 atomic bombings of Hiroshima and Nagasaki by the United States, the consequences which have been continually studied. There was also the 1986 accident at the Chernobyl nuclear plant in Ukraine – the largest uncontrolled radioactive release in history.

There are several stages to a nuclear explosion, explains Arik Eisenkraft, an associate professor in the Department of Military Medicine at the Hebrew University, Jerusalem and the IDF Medical Corps. Within the first phase, there is a devastating, destructive blast that, like an earthquake, causes the collapse of any buildings or infrastructure not strong enough to sustain it. A heat wave follows shortly thereafter.

“We are talking about incineration,” Eisenkraft says. “Everything is burnt. And, as a result of the consumption of oxygen, you get a sucking effect into the center of the blast, which causes another wave of shattering destruction on top of the lack of oxygen. If people survive the first, immediate event, then shortly thereafter, they cannot really breathe in the area.”

“All the proteins in the body are boiling,” describes Yoel Hareven, director of the International Division & Resource Development at Sheba Medical Center. “Your cells are like eggs boiling but without any fire.”

“At relatively low doses, [radiation] impairs bone marrow,” WHO writes. “At higher doses, damage occurs in the gastrointestinal tract; and at very high doses, there is injury to the brain.”

But the event does not end with the blast. 

Everything inside this fireball vaporizes – including the soil and water – and is carried upwards to form a “mushroom cloud.” Radioactive material from the nuclear device mixes with the vaporized material. As it cools, it becomes condensed and forms particles that fall back to the earth, entering the soil and the aquifers. These radioactive particles can also be carried great distances by the wind. 

“In Chernobyl, for example, in the first few days, the only affected area was the nearby town. But within a few weeks, there were alerts of high radiation in Sweden, Spain and France,” Eisenkraft explains. “The wind took the cloud and dispersed the radioactive materials all across Europe.”

While people living in these areas are not immediately killed, the Centers for Disease Control and Prevention (CDC) says that external exposure to lower doses of radiation and internal exposure from breathing or eating food contaminated with radioactive fallout may lead to an increased risk of developing cancer and other health effects.

Another immediate source of destruction is the collapse of critical infrastructure. If hospitals were in the area, Eisenkraft says, they would also be damaged. Moreover, the electromagnetic pulse of such a blast leads to the impairment of electronic devices, including those needed for health services. 

“It damages all electronics, so you do not have computers. You do not have the Internet,” the professor explains. “All of the computers that are managing the ventilators are not there anymore. All intensive care efforts are now being performed in relatively primitive ways, simply because you do not have any active machines anymore.”

The laboratory capabilities needed to properly treat the injured are nonexistent, he continues. Patients would need to be transferred to neighboring facilities, overburdening hospitals that would also be tasked with providing routine care, such as to pregnant women or people suffering from cardiac arrest. 

This is not to mention airplanes that might coincidentally be in the same area, he says. They would simply shut off during flight and crash. Cars, which today are all digitized, would cease to work, only adding to the chaos. 

Doctors and other health workers would be among the most at risk, tasked with setting up field hospitals just outside the contaminated areas. While those exposed directly to radiation are severely injured, they cannot contaminate anyone else. However, patients who are covered with radioactive dust could pass it on to healthcare workers, exposing them to short- and long-term risks. 

“In order to make sure providers are not exposed and hurt, you have to decontaminate all the people before you start treating them, which makes everything even more complicated,” Eisenkraft says. “In order to decontaminate everyone, you need to have showers, you need infrastructure, pumps, access to clean water. All of this would be challenging, if not impossible, in such a scenario.”

Moreover, WHO explains, a nuclear explosion would destroy public health and sanitary facilities, opening the way for the spread of disease. 

“Water supplies would be contaminated not only by radioactivity but also pathogenic bacteria and viruses,” writes WHO. “Sewage treatment and waste disposal facilities would have almost completely disappeared. Great numbers of putrefying human bodies and animal carcasses, as well as untreated waste and sewage, would provide easy breeding ground for flies and other insects.”

The result would be diseases like salmonella, shingles, hepatitis, dysentery, malaria, typhus and tuberculosis in epidemic form, according to WHO. 

Finally, as the radioactive substances enter the ground and water, it will contaminate the food supply chain. Meat and milk products made from contaminated livestock will pass on to the humans who consume them. Crops and the marine ecosystem will similarly suffer. 

“There will be a severe shortage of edible and sustaining substances at a time when the victims’ needs are greatest,” WHO says. 

Some 30 years after Chernobyl, around 5,000 cases of thyroid cancer were developed in young adults, who had been children at the time of the incident, the United Nation Scientific Committee on the Effects of Atomic Radiation reported. This is likely due to their drinking fresh milk containing radioactive iodine from cows who had eaten contaminated grass in the first few weeks following the accident.

The only choice, therefore, is to leave the area, explains Hareven.

“No one is living in Chernobyl right now” nearly 40 years later,” Hareven says. “It is totally abandoned.” 

He adds that nuclear power does not have a smell and you cannot see it, so it is almost impossible to know when it is in the air. 

Treatment options: Limited

The most common effect on survivors is radiation poisoning, known in the medical world as acute radiation syndrome (ARS), which causes a decrease in blood cells, explains Yaky Yanay, CEO and president of Haifa-based Pluri, formerly known as Pluristem. He says radiation attacks all three blood lineages – white and red blood cells and platelets.

Low white blood cell count weakens the immune system, making an individual vulnerable to infection. Red blood cells carry oxygen to the body. Platelets are responsible for coagulation, preventing bleeding.

Although some treatments similar to what are provided to cancer patients can help these patients, Hareven says, these treatments take time to administer and often need to be tailor-made for each victim. When there are a small number of patients, these treatments can be successful; but in a mass casualty event, it would be highly complex to manage.

“There are medications approved by the Food and Drug Administration that the US Department of Defense has stockpiled,” like G-CSF, which helps the bone marrow make more white blood cells, explains Nitsan Halevy, Pluri’s chief medical officer. “But this treatment has to be administered  daily by either intravenous or subcutaneous administration, and patients need to be monitored by having a blood test twice a week to check their blood count.”

The FDA has cleared Pluri’s PLX-R18 as an “investigational new drug” (IND) in the treatment of ARS, which would allow the company to treat victims who may have been acutely exposed to high dose radiation due to nuclear attack or accident in the context of a clinical study. PLX-R18 is a simple injection of placenta cells into the thigh muscle and has been found in pre-clinical animal trials to induce a victim’s body to create new blood cells, repopulating the blood system.

PLX-R18 cells are derived predominantly from the fetal portions of full-term placentae donated following Cesarean section. They are expanded using the company’s 3D bioreactor technology. The cells are considered an “off-the-shelf” product that doesn’t require the matching of tissues between the donor and recipient, so they can be administered instantly and in the field in the event of a multiple casualty radiation attack. 

Each placenta can produce more than 20,000 treatment doses, which are cryopreserved in very low temperatures, says Halevy. They can be shipped anywhere in the US within four hours. The vials take only minutes to thaw.

In March, the company reported that its cells were tested in a small Phase I study in the United States and Israel to evaluate its safety among people with incomplete hematopoietic recovery following bone marrow transplantation. This can be life threatening, as patients become vulnerable to bleeding and recurrent infections – similar to actively being exposed to radiation. 

PLX-R18 was found to be well tolerated with a favorable safety profile, a report on the trial said. Patients treated with the cells showed an increase in all three blood cell types compared to baseline within one month following administration and lasting up to 12 months. The need for transfusions was also reduced.

The observed annual mortality rate following PLX-R18 administration was 18% compared to 29% compared to similar patients, based on data obtained from the Center for International Blood and Marrow Transplant Research registry.

In addition, working with the US National Institutes of Health and the US Department of Defense, PLX-R18 was tested pre-clinically as a prophylactic countermeasure that could be administered to soldiers and emergency responders who might be called into a nuclear radiation zone following an attack. 

In a recent article published in the peer-reviewed journal Genes, researchers reported for the first time that the treatment is effective when administered 24 hours prior to total body irradiation and three days after. 

Mice that received PLX-R18 “demonstrated faster recovery from radiation-induced peripheral blood cytopenia, accelerated restoration of the clonogenic potential of femoral bone marrow, and improved megakaryocyte counts in sternal bone marrow” compared to mice that were treated with standard care. 

The survival rate of the animals increased to 81% compared to 23%, the report said.

“We hope these results could be replicated in humans if and when the time comes,” Halevy cautions. “We cannot run randomized clinical studies like you would in other cases, and the results are never 100% transferable.”

The best way to stay safe, therefore, is to avoid nuclear war.

As Ioannis William Kokkinakis and Dimitris Drikakis write in their new paper published January 17 in the peer-reviewed journal Physics of Fluids: “There is no good place to be when a nuclear bomb goes off.” ■