Effects of the Chernobyl Disaster

Lore & Background

The first evidence of the release came not from Soviet sources but from Sweden. On 28 April, two days after the accident, workers at the Forsmark Nuclear Power Plant, approximately 1100 km from the site, were found to have radioactive particles on their clothing, and the raised readings were traced back to the western Soviet Union. Instruments in Finland had picked up rising radiation a day earlier, but a civil service strike delayed the response.

Soviet scientists reported that 28,000 square kilometers were contaminated by caesium-137 above a level of 185 kBq per square meter, an area where 830,000 people lived. About 10,500 km2 were contaminated above 555 kBq/m2, most of it in Belarus. Fallout was scattered unevenly by the weather, and much of it came down with rain over mountainous regions such as the Alps and the Scottish Highlands.

Reader's Guide

Comparisons with nuclear weapons are difficult. The accident is estimated to have released about 400 times more radioactive material than the bombings of Hiroshima and Nagasaki combined, yet only a small fraction of the total released by weapons testing at the height of the Cold War. A scientific committee has argued that the two cannot simply be ranked as better or worse, partly because the isotopes from the plant tended to be longer-lived.

Belarus bore a heavy share. Reports indicate that it received about 60% of the contamination that fell on the former Soviet Union, and rain was deliberately seeded over part of its territory to wash particles out of clouds heading for populated areas. A report of 2006 stated that up to half of the volatile particles landed outside Ukraine, Belarus and Russia.

Did You Know?

• Heavy, black-coloured rain fell on the city of Gomel.
• Sweden and Norway received heavy fallout when contaminated air met a cold front.