The Chernobyl disaster: cancer following the accident at the Chernobyl nuclear power plant.

The Chernobyl nuclear power plant, located in Ukraine about 130 km north of the capital of Kiev and about 10 km south of the border with Belarus, was the scene of the most severe accident that has ever occurred in the nuclear industry. On April 26, 1986, two violent explosions destroyed the core of unit 4 of the power plant and the roof of the building, resulting in a series of fires and in massive releases of radioactive materials into the atmosphere. The releases consisted of gases, aerosols, and finely fragmented nuclear fuel particles. From the radiologic point of view, iodine-131 (131I) and cesium-137 (137Cs) are the most important radionuclides to consider (1, 2). During the 10 days of massive releases, the wind direction changed frequently, so that all areas surrounding the reactor received some fallout at one time or another. In addition, rainfall occurred in an irregular pattern, causing varying degrees of deposition. The releases of radioactive materials were such that contamination of the ground was found to some extent in every country in the Northern Hemisphere (3). However, the most contaminated areas were in Belarus, Russia, and Ukraine (table 1).