STEVE INSKEEP, host:
The accident at Chernobyl changed the lives of many people in Ukraine. But it did more than that. It put a radioactive stain on many parts of Europe, showing how far-reaching a serious nuclear accident could be.
NPR's Christopher Joyce reports on the costs that are still coming due a quarter-century later.
CHRISTOPHER JOYCE: On those late April days in 1986, plumes of radioactive smoke spread for thousands of square miles - across Ukraine, the former Soviet Union, Europe, Scandinavia. Beyond 20 miles or so from the reactor, the doses did not pose an immediate health threat, but what about long-term effects of low-level exposures? Calculations say the accident has and will cause thousands of cancer deaths. But so many people get cancer, it's hard to tease out the extra ones caused by Chernobyl.
Radiologist Fred Mettler has been trying to do that with a special United Nations radiation group.
Dr. FRED METTLER (Radiologist): You would have 20 million people over that time dying of cancer generally, and now you're trying to find 4,000 extra cases or 10,000 extra cases. That signal is pretty much too small to actually be able to see.
JOYCE: To really isolate cancers caused by Chernobyl, Mettler says scientists need to know patient histories: Did they smoke, drink heavily, have cancer in the family?
Dr. METTLER: Unfortunately, most of these countries are not sharing their data on health effects back and forth.
JOYCE: Mettler says the easiest Chernobyl cancers to detect are thyroid cancers. Normally they're rare and are known to be caused by radioactive iodine, of which there was plenty floating around after the accident. Mettler says about 7,000 people got thyroid cancer from the radiation. The vast majority of these have been cured, but there will be more cases. How many more is a mystery.
Dr. METTLER: 'Cause we know it went up in those that were exposed as children, the public and so forth. And it's gone up. We don't know whether that risk is going to go down over time or keep going up or level off. That's probably the biggest thing that's going to be studied and focused on.
JOYCE: Mettler and other scientists say the residents who have moved back, as well as the hundreds of thousands of so-called liquidators who returned to clean up the site, are a potential gold mine of information. They are the only large population of people exposed to low levels of radiation since the Japanese survivors at Nagasaki and Hiroshima. But finding them, their medical records, or the money to do the research, is doubtful.
What worries some health professionals more than radiation are the psychological effects of the accident. James Smith, a physicist at the University of Portsmouth, who has studied Chernobyl for two decades, says several studies found high rates of suicide, depression and mental health problems in the region after Chernobyl.
Dr. JAMES SMITH (University of Portsmouth): Having to live with radiation -knowing that you've been exposed - gives an additional psychological stress because the information hasn't always been reliable. So people don't always know what the risk to their health really is.
JOYCE: And Smith says Chernobyl remains an open sore for Ukraine. The government is trying to raise hundreds of millions of dollars to construct a huge building that will cover the crumbling concrete sarcophagus that now keeps the highly radioactive plant isolated.
And then there's the radiation that's still locked up in the environment, largely out-of-sight but potentially dangerous. For example, there's lots of long-lasting cesium bound up in the forests and soil around the plant.
Chad Oliver is a forestry professor at Yale University who's been there.
Professor CHAD OLIVER (Yale University): The forests have been crowded and untended, and they're on soils and in a climate that they could very well go up in a catastrophic fire similar to our Western fires. The problem with a catastrophic fire is that they even create their own weather patterns, so you get some very tremendous dispersion of smoke.
JOYCE: The radioactive smoke might not be deadly as far as the city of Kiev, about 100 miles away, but the local effects could be very dangerous.
Mr. OLIVER: The worst concern is the firefighters that are going in there would be inhaling - that close, it would be quite concentrated radioactive smoke.
JOYCE: Oliver says the firefighting equipment near the site is outdated and roads are poor. Recently, though, the U.S. Forest Service has been pitching in. Teams from the service are advising Ukraine on how to cull trees and remove downed wood to lower the fire hazard. They're also studying wind and weather patterns in case another conflagration hits Chernobyl.
Christopher Joyce, NPR News.
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