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pregnant women during their pregnancies when women were x-rayed, the children of those pregnancies had a higher cancer rate. And this is at a very low level of radiation. And her work and subsequent work led to the rather strict practices that are in place now to try and eliminate as much as possible the use of even low level ionizing radiation, the kind used routinely in medical diagnosis for pregnant women. So that is an indication that radiation can lead to damage even at low levels as well as high levels. By now, quite a few studies in the nuclear industry have shown relationships between the radiation doses received by workers in the nuclear industry and their subsequent cancer rates. I thought that I would present to you just a little information about one case here in the United States that I think may have some interest in relation to our situation here in the Triangle area. What I want to talk about is the accident at Three Mile Island. I want to talk about a study that a group of us here at UNC published in a journal called, "Environmental Health Perspectives" a few years ago. This is the journal of the National Institute of Environmental Health Sciences. I want to talk about the Three Mile Island area in part because I think that there are some interesting similarities to the Triangle area. This is a picture of Three Mile Island, which is in the Susquehanna River in southeast Pennsylvania. It is a fairly rural area. You can see the river and the cooling towers of the plant in the background. This is a picture taken just a few miles from the site. You can see that this is an area where there are small towns, there are farms, it is a rural area, and the population includes a lot of elderly people, kind of traditional lifestyles. People take their boats like they do to Jordan Lake. There are small neighborhoods around Three Mile Island. I guess I think of this area reminding me a little bit about what it would be like around Apex or in Chatham County and so on. After the accident the data were collected by a group from Columbia University. They actually obtained information about cases of cancer from 15 local hospitals. The group from Columbia University identified an area of ten miles in radius around the plant. The design of the study was that they were going to compare groups of people within the ten-mile area with each other, according to their radiation exposures. And this was important because after an accident like this, there is naturally increased concern about cancer, people might go to the doctor sooner, and doctors may look more frequently for cancer because they know about the accident. So rather than trying to compare the Three Mile Island area to some other area that did not experience a nuclear accident, they decided that they would look just within the ten-mile area and try and identify the more and less exposed people. So the ten-mile area there had about 160,000 people. They surveyed 15 local hospitals and identified cancer cases that occurred both before and after the accident. And this was important because there is geographic variation in cancer all over the place, whether or not there are nuclear facilities, and they wanted to be able to control for this variation what the cancer rates were before the accident when they looked at potential effects of the accident. They estimated doses from the accident using some monitoring data. The monitors on-site went off scale, but there were some monitors that were available. And there was an airport right near Three Mile Island, so that airport was able to provide meteorological data, and they were able to model the emissions of the plumes from the accident. What I want to show you here next is the results of our study. This is a schematic diagram. The Columbia group divided the ten-mile area into 69 small tracts. To each tract they assigned a radiation dose, and that is shown in the different colors —from the green, the lowest doses, to the dark red, the highest doses. And so you can see that the investigators estimated that the strongest plumes of radiation from the accident in 1979 went in a west-northwesterly direction from Three Mile Island. I would note also that the second highest dose group runs right to the edge of the ten-mile area. That's the direction of Harrisburg, which is the capital of Pennsylvania. That is another similarity with this area, is that just outside of the ten-mile area is our state capital. The bottom of the graph shows the estimates that we made of the incidents of lung cancer in the seven years following the accident. Actually, this is the 1981-85 period - the accident was in 1979. These rates have