The biological impacts of ingested radioactive materials on the pale grass blue butterfly.
A massive amount of radioactive materials has been released into the environment by the Fukushima Dai-ichi Nuclear Power Plant accident, but its biological impacts have rarely been examined. Here, we have quantitatively evaluated the relationship between the dose of ingested radioactive cesium and mortality and abnormality rates using the pale grass blue butterfly, Zizeeria maha. When larvae from Okinawa, which is likely the least polluted locality in Japan, were fed leaves collected from polluted localities, mortality and abnormality rates increased sharply at low doses in response to the ingested cesium dose. This dose-response relationship was best fitted by power function models, which indicated that the half lethal and abnormal doses were 1.9 and 0.76 Bq per larva, corresponding to 54,000 and 22,000 Bq per kilogram body weight, respectively. Both the retention of radioactive cesium in a pupa relative to the ingested dose throughout the larval stage and the accumulation of radioactive cesium in a pupa relative to the activity concentration in a diet were highest at the lowest level of cesium ingested. We conclude that the risk of ingesting a polluted diet is realistic, at least for this butterfly, and likely for certain other organisms living in the polluted area.
The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science.
Chiyo
C
Nohara
The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science.
Atsuki
A
Hiyama
The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science.
Wataru
W
Taira
Instrumental Research Center, University of the Ryukyus, Okinawa 903-0213, Japan.
Akira
A
Tanahara
The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science.
Joji M
JM
Otaki
D000818:Animals; D002080:Butterflies / Q000254:growth & development* / Q000528:radiation effects; D002588:Cesium Radioisotopes / Q000032:analysis*; D004435:Eating; D062406:Fukushima Nuclear Accident; D007564:Japan; D007814:Larva / Q000254:growth & development* / Q000528:radiation effects; D011679:Pupa / Q000254:growth & development* / Q000528:radiation effects; D011834:Radiation Monitoring; D011848:Radioactive Pollutants / Q000009:adverse effects*
D002588:Cesium Radioisotopes; D011848:Radioactive Pollutants