[muxl]

I agree there are some claims in this article that should be further scrutinized but it's true that the levels of radiation were not as high as one might assume. The direction of the wind during and immediately following the disaster slowed the spread of radioactive material over Pripyat (this is also why southern Belarus was hit so hard). The prevailing winds in that region are north east and the Chernobyl power plant was on the north side of the city. By the time of the May day parade the winds had shifted such that Kiev was downwind from Chernobyl.

The KGB did their best to contain information about the disaster in general and the USSR wanted the May day parade to go on as-planned to make it look like things were fine. Even those with enough power or connections to be aware of the danger were pressured to participate. The May day parade was later often referred to in infamy by the Ukrainian independence movement following the disaster.

Most of my information comes from what I remember of reading "Midnight in Chernobyl" and "Chernobyl the History of a Nuclear Disaster"