I remember the Chernobyl disaster. The local University (Dundee) Physics department decided to take a sample from an Estonian coal ship (about 800-900 miles North of the Chernobyl reactor) that had docked at Dundee Docks about 3-4 weeks after the explosion. The coal dust sample turned out to be the hottest radiological source at the University and legally had to be disposed off under nuclear reprocessing legislation and had to be sent to Sellafield reprocessing/storage site in Cumbria.

Governments will keep folks in the dark, just as they did in the Windscale fire in 1957. National security interests such as too 'don't panic the population' always become convenient reason for not telling the truth to the dangers of nuclear fallout. Even Andrei Sakharov begged to the political leadership of the old USSR not to detonate the Tsar bomb because of the 30-60,000 deaths he calculated the bomb would cause due to the fallout.