Researchers compared monkeys from two regions of Japan, one group of monkeys from the Shimokita region, 400 Km north of Fukushima and monkeys from contaminated land in Fukushima.
"Fukushima monkeys had significantly low white and red blood cell counts, hemoglobin, and hematocrit, and the white blood cell count in immature monkeys showed a significant negative correlation with muscle cesium concentration. These results suggest that the exposure to some form of radioactive material contributed to hematological changes in Fukushima monkeys."
Changes in blood are also found in people inhabiting contaminated areas around Chernobyl. Nature