| Project/Area Number |
63570238
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Hygiene
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
OKUDA Hisanori Hiroshima University, School of Medicine, Professor., 医学部, 教授 (60033958)
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| Co-Investigator(Kenkyū-buntansha) |
IMADA Atsushi Hiroshima University, School of Medicine, Research Associate., 医学部, 助手 (00112201)
HIRAOKA Yukio Hiroshima University, School of Medicine, Assistant Professor., 医学部, 講師 (00144816)
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| Project Period (FY) |
1988 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1989: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1988: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | Herbicide / Degraded solution / Mouse fetus / Medaka egg / メダカ / マウス / 除草剤分解液 |
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| Research Abstract |
We carried out some experiments in order to ascertain the effects of a diphenyl ether herbicide, which is used quite frequently in Hiroshima prefecture, on a medaka and a mouse fetus.
The CNP emulsion was exposed to sunlight until the CNP concentration became 10% of the initial CNP concentration. CNP, degradation products, and the likes were extracted from the mixture by n-hexane and evaporated it to concentrate. The undegraded and degraded solutions of CNP emulsion were administered subcutaneously to the backs of pregnant mice from the 6th to 15th fetal day, once dally. The mice were sacrificed on the 18th day of pregnancy. The number of fetuses and implantations, their weights, externals and skeletons were observed. Mean fetal body weights of the undegraded and degraded solution dose groups were significantly lower than those of the control. Fetal skeletal abnormalities were higher than those of the control.
Nedaka eggs at the morula stage were exposed for 5 days to an undegraded CNP e
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mulsion, Its degraded solution by exposure to sunlight and a standard CNP solution. The number and appearance of newly hatched fry were then observed. Adult fish were exposed to these test solutions for 24 or 48 hrs and the survivors were counted. CNP concentrations in the test solutions were measured after 3, 6, 12 and 24 hrs. Hatching rates and survival rates in the undegraded solutions and the standard CNP solution were significantly higher than those in the control. Abnormal fry were frequently occurred in the undegraded solution. The effects of the degraded solution on the hatching rate, the survival rate, and the occurrence of abnormal fry was lower than in the other two solutions. The residual rates of CNP in the degraded solutions after 24 hrs was less than 10% and the greater part of the CNP added at the commencement was adsorbed on the container wall.
From these results, it is suggested that CNP emulsion which is used frequently because of the high safety have a noticeable toxicity to medaka and the toxicity of the degraded solution to mouse fetus cannot be disregarded. Less
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