Found this from a news source I've been using a lot:

^Tepco has reported results from analysis of plutonium at five places at the Fukushima Daiichi site.^

^Three of the five samples showed the element at the pervasive levels found across Japan as a result of atmospheric nuclear weapons tests. This level poses "no major impact on human health", said Tepco. However, slightly higher detections from two samples "may be attributed to the accident, considering the plutonium isotope ratios." Tepco did not speculate on a possible route for the plutonium to have been deposited on the soil. Three more analyses from different spots are underway.^

Still no actual quantities, though. Radioactive elements are detectable at atomic quantities. Units are always important in these stories.