Later The world did not know that something was wrong until two days after the accident when technicians in Sweden discovered unusually high levels of radiation in the air. Although, Soviets worked frantically and heroically trying to contain the damaged reactor, there was only so much that could be done. Tens of thousands of local residents were evacuated from the area and many were given iodine pills to prevent their bodies from absorbing radioactive materials. As the reactor burned, it slowly released dangerous radioactivity into the air.
Poisonous chemicals spread on the wind.
The rain and spring snow, which fell gently on Finland and Sweden, captured the radioactive materials depositing them throughout Scandinavia. The radiation had taken its lethal path across the Soviet Union's best farmland and north to Scandinavia. By the end of the week the stream of radiation had changed course and spread across Eastern Europe as well as to the shores of the Mediterranean. The Soviets eventually succeeded in capping the ruined reactor with a concrete sarcophagus designed to contain the radiation. However, six years later, when TIME's James Jackson visited the plant.