STEVE INSKEEP, Host:
NPR's Christopher Joyce reports on the costs that are still coming due a quarter-century later.
CHRISTOPHER JOYCE: Radiologist Fred Mettler has been trying to do that with a special United Nations radiation group.
FRED METTLER: 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?
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.
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: 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.
JAMES SMITH: 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: Chad Oliver is a forestry professor at Yale University who's been there.
CHAD OLIVER: 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.
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: Christopher Joyce, NPR News.
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