Charles Choi's dispatches from Chernobyl

Back in December,'s Charles Choi wrote an article about tourism at the Chernobyl disaster site. Guess where he's reporting from this week?


I drove to Chernobyl with health physicist Vadim Chumak at the Research Center for Radiation Medicine at the Health physicist Vadim ChumakAcademy of Medical Sciences of Ukraine and his colleagues. A car shuttles there every week to collect stool samples from workers to test for any plutonium they might have accidentally absorbed. (Science, like journalism, can be a dirty job, but someone has to do it.)

The world is normally bathed in a low level of radiation. In Kiev, where I started my trip, one normally receives 0.1 millionths of a sievert every hour. This is pretty much the level of radiation we saw on the road on the roughly two-hour, 150-kilometer drive into the exclusion zone, but readings on our dosimeter temporarily climb up to 4.76 millionths of a sievert per hour when our car passes through the old path of the radioactive plume from the destroyed reactor.

How safe this area is now after the accident depends on what radioactive material was released and where it went. There are four kinds of radionuclides or radioactive isotopes that are of special concern at the site. Iodine-131 is rapidly absorbed by the thyroid gland and increases the risk of childhood thyroid cancer. Cesium-137 mimics potassium inside the body, seeking out muscle. Strontium-90 acts like calcium, attracted to bone. Plutonium-239 and other isotopes can stay in the body indefinitely, irradiating organs.

These four materials escaped from the explosions to varying distances, given factors such as their mass and melting points. Iodine-131 and cesium-137 were both very broadly transported hundreds of kilometers, while strontium-90 remained in dust just 30 kilometers from the power plant and plutonium traveled only four kilometers or so.

Iodine-131 decays rapidly, and was virtually gone from the environment after only three months, Chumak says. However, cesium-137 and strontium-90 both have approximately 30-year half-lives, meaning they each take roughly three decades for half their material to decay, and plutonium-239, one the main isotopes in nuclear reactors, has a half-life of more than 24,000 years.

There's some really interesting stuff in here. The Chernobyl exclusion zone isn't one monolithic thing, Choi discovers. Some areas are already reasonably safe, while others are places that humans will probably never live again. Even the animal impacts are varied. The creatures that live here are thriving, and don't seem to be passing on genetic mutations. But, Choi points out, the species diversity has gone down significantly since the accident.

This is just the first in a series of articles Choi will be writing for Scientific American from his trip to Chernobyl.

Photo: Charles Choi. Taken inside the control room for destroyed reactor No. 4 at the Chernobyl nuclear power plant.


  1. Oddly I was just playing the 2007 game Stalker: Shadow of Chernobyl. It’s set in an imagined Chernobyl wasteland with a good mix of science fiction (mutants, odd anomalies, etc.). It was so odd to be paying this game while on the other computer, events in Japan were playing out.

  2. “These four materials escaped from the explosions to varying distances…”

    Is this about Chernobyl or Fukushima? I’m confused.

  3. Good try Maggie.

    If the concern is long-term effects, Chernobyl is THE example. (Also worse than Japan)

    The Iodine made you sick right away, the Plutonium has very little effect, so the long-term concerns are the Strontium, and especially the Cesium.

    Strontium is not well preserved in the environment over the long term (medium term is another issue) but Cesium is, and known to collect in vulnerable tissues.

    But like dosage, vector matters. In oder:
    and the most serious there now:
    Fallout-> Groundwater-> Plants-> Humans
    In short, the worst meltdown in human history (due to the dumbest sort of human error and poor management) has still probably done less damage than an average coal plant. Priorities, people!

    But a lot of the western public has bought the nuclear power = nuclear bomb rhetoric. They equate Nagasaki with meltdowns, and that’s the end. Never mind that a Nagasaki-traumatised Japan *built* those things, for good engineering reasons.

    1. The “engineering reasons” were soundly criticized from day one. They were built for political and (faulty) economic reasons. The agency responsible for the nukes has a long history of deception of the public. Plutonium has very little effect? A particle in the lungs WILL cause cancer.

      These plants were a disaster waiting to happen. The catastrophe is not even close to over. The cost to replace the power and mitigate the damage will cost much more than was ever gained by building the plants. That’s the fatal flaw of nukes. Accidents may be rare but their rarity does not make up for the damage caused when things go wrong.

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