The Journal of Epidemiology and Community Health reported more than 800 people in Sweden may have cancer as a result of the fallout of the Chernobyl nuclear accident (occurred way back in 1986). The epidemiological investigation included cancer cases among the more than 1.1 million people in the northern parts of Sweden where the radioactive fallout cloud traveled.
Of the 22,400 cancer cases among the group, 849 were found by the investigators to be statistically attributed to Chernobyl.
One thing this tells us is that epidemiological intervention is not always an immediate one! What other things can you think of that we have tracked from other countries?
I have not seen this article, but as a Swedish specialist in radiation therapy and radiation protection I have serious objections to any such conclusions, at least as they are presented in your question. Apart from the connection between radioactive iodine and thyroid cancer there is no simple clear cut connection linking any cancer case with a radioactive fall out like this! We do know however that there can be connections to leukemia with a maximum risk around 10 years after exposure and to solid cancers. Those however can appear decades after exposure. All we can use in a situation like ...