2005 Fiscal Year Final Research Report Summary
The elucidation of the historical trend of the anthropogenic pollution in Kinki area after the Meiji era using aquatic sediment.
| Project/Area Number |
16510012
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Environmental dynamic analysis
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| Research Institution | Kinki University |
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Principal Investigator |
YAMAZAKI Hideo Kinki University, School of Science and Engineering, Associate Professor, 理工学部, 助教授 (30140312)
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| Project Period (FY) |
2004 – 2005
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| Keywords | Anthropogenic Pollution / Historical Trend / Heavy Metal / Mercury / Lead / Aquatic Environment / Sediment / Lake Biwa |
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| Research Abstract |
The historical trend of anthropogenic heavy metal pollution in Kinki area was studied using the aquatic sediment. The core sediment samples were collected in Lake Biwa, Osaka Bay, Odaka Castle moat and urban reservoir. The core sample was cut off at 1-2cm thicknesses. The sample dried at 60-70℃, then it was ground using the agate mortar. Simultaneous determination of major and trace elements of 21 was determined by the fluorescent X-ray spectrometry. The mercury was determined by the heating vaporization-atomic absorption spectrometry. The core chronology was constructed by radiometric dating using ^<210>Pb and ^<137>Cs. The activities of 210Pb and 137Cs in sediments were analyzed by gamma spectrometry using HPGe detector coupled to a 4096 channel multichannel analyzer.
From the results of analyses of the concentration-change of heavy metals recorded at the core sediments, the historical trend of heavy metal pollution in Kinki area was clarified. The local pollution was recorded in the
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sediment of Osaka Castle moat and urban reservoir. The historical pollution profile, which flowed from the catchment area in the Keihanshin district, was observed in the Osaka Bay sediments. The source of anthropogenic heavy metals in the Lake Biwa sediment seemed to flow from its catchment area, and it seemed to have been carried by the atmospheric transport from Keihanshin district.
All sediment samples have been contaminated in the heavy metals such as chromium, nickel, copper, zinc, mercury and lead anthropogenically discharged to the environment in industrial activity. The heavy metal pollution of the sediment begins after the Meiji restoration, and it continues by the present. Concentrations of heavy metals rapidly increased in 1900's, and the maximum values are shown in 1970. However, the peak of the mercury contamination in Lake Biwa appeared in 1960. The organic mercury compound extracted with benzene was detected in the 1960's layer of the sediment. Therefore, it was estimated that there were mercuric pesticides that the source of mercury contamination in Lake Biwa in the generation was sprayed over the paddy field in the circumference this time.
From the historical trend of the heavy metal contamination recorded in bottom sediment of the hydrosphere, the relationship between human activity and anthropogenic environmental pollution in Kinki area after Meiji era was clarified. Less
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