1. Health
You can opt-out at any time. Please refer to our privacy policy for contact information.

Discuss in my forum

Chernobyl: History of a Nuclear Disaster

25 Years Later, Chernobyl Is Still Linked to Thyroid and Other Health Effects


Updated June 21, 2014

Chernobyl: History of a Nuclear Disaster

25 years after the Chernobyl disaster, the health effects are still felt in the former Soviet Union

Ezra Shaw / Getty Images News
On April 26th, 1986 at 1:23 am, things in Chernobyl, a tiny town in the Soviet countryside, went very wrong. Today the name "Chernobyl" is a touchstone, a single word that means "nuclear disaster" to people around the world. Chernobyl was in fact the worst nuclear accident in history. Even though the March 2011 Fukushima reactor accident was judged to be as "serious" as Chernobyl by nuclear authorities, it's thought that the radiation release in Japan was far less than in Chernobyl, and the fall out had less impact on other regions. Still, it may be years before we know if Chernobyl will continue to hold the dubious distinction of being the world's worst nuclear disaster.

In any case, Chernobyl has been of particular interest to thyroid practitioners and patients, because one of the radioisotopes released during nuclear reactor accidents -- including the Chernobyl disaster -- is iodine 131, also known as radioactive iodine, or radioiodine.

Iodine 131 has a half-life of eight days, meaning that half of it disperses every eight days. This fairly long half-life (when you compare it to some radioiosotopes, which have half-lives of seconds or minutes) means that radioactive iodine can quickly get into the human food supply by contaminating plants, animals and water, and well before a significant amount of the radiation decays and disperses. Once ingested, radioactive iodine concentrates almost exclusively in the thyroid gland, where the radiation can cause either destruction of the gland, or act as a long-term trigger for development of thyroid cancer and other thyroid problems. Young children and fetuses, who have developing and fast-growing thyroid glands, are the most susceptible to exposure to radioactive iodine, and the effects of exposure also tend to show up more quickly in children compared to adults. Children also are the main consumers of milk, and when cows eat radioactive iodine-contaminated grass, the iodine concentrates heavily in milk, making milk consumption another key pathway for exposure to radioactive iodine.

As we mark the 25th anniversary of the Chernobyl disaster, it's important to review some history behind the Chernobyl crisis, and the health impact of the crisis, not only in on thyroid health, but other health effects as well.

Some Chernobyl Geography and Political History

The small town of Chernobyl is located in the province -- known as an "Oblast" -- of the Kiev district in Ukraine. In 1986, Ukraine was a state of what was still the Soviet Union. Chernobyl is located 110 miles from Kiev, 22 miles from Ukraine's border with the Gomel Oblast of Belarus, and near the Bryansk Oblast of Russia. The Chernobyl region was primarily an area populated by small-town farmers.

The nuclear plant, originally built as part of the Soviet Union's nuclear weapons program, was located two miles outside of the main part of the town of Chernobyl itself. The reactor was located at the junction of two rivers, the Pripyat and Uzh, near the Kiev reservoir, which provided a plentiful supply of water for cooling. Over time, the plant was converted for use as a civilian power station.

The official Soviet policy was to minimize information dissemination or discussion of problems related to the construction, maintenance, and operating procedures at nuclear plants. We now know that as a result of this narrow-minded thinking, throughout the former Soviet Union, there was minimal training, disaster drills, and preparedness for nuclear emergencies, and Chernobyl was no exception. The Soviet Union also operated under a political system that left Moscow with tremendous power over its various republics and regions, so the Chernobyl region, as part of Ukraine, was under the political rule of decision makers thousands of miles away in Moscow.

As a result, when the nuclear disaster struck at Chernobyl, not only were the plant's staff and the region's residents unprepared to respond appropriately to a nuclear accident, but the response was stalled, as local officials waited for direction from Moscow. It has been reported that even as radiation leaked from the crippled reactor, children were being sent to school, an outdoor wedding was held, a soccer match took place, and local residents went fishing in the nuclear plant's cooling ponds.

According to United Nations reports (1), it was actually two full days -- after one reactor had already blown up, and a second was on fire -- before Moscow even acknowledged that "something" had happened in Chernobyl, much less revealed the magnitude of the disaster.

What Did Happen at Chernobyl?

The International Atomic Energy Agency has described what happened to cause the Chernobyl nuclear disaster. Reportedly, while workers were conducting a test of Reactor Four, a huge power surge hit the Chernobyl plant , resulting in an explosion and fire, which released a huge plume of radiation into the atmosphere. The design of the Chernobyl reactors was considered outdated, and had no containment structure to protect the surrounding area from leaked radiation. Reactor Four's explosion released more than 100 different radioactive elements into the environment.

Two workers at the plant were killed immediately. Many of the first responders were reported to have died very soon after they responded to the accident, and most within three months of the initial explosion. Helicopter pilots who worked at the site in the early days ended up being airlifted to Moscow for treatment within days and weeks of helping to contain the accident.

In the earliest days, approximately 49,000 immediate residents were evacuated from the area, but were told they would be displaced for only two or three days.

In the following weeks, more explosions occurred, but the risks to the region were denied or minimized. Soviet officials did not even acknowledge some of the subsequent blasts at the plant, and were assuring the public that the situation had totally stabilized and that radioactive levels in the area were normal.

©2014 About.com. All rights reserved.

We comply with the HONcode standard
for trustworthy health
information: verify here.