著者

Moono SHIN Tomijiro KUBOTA Koji HAMADA Tadayoshi HITOMI Takeshi OTA

出版者

日本水環境学会

雑誌

Journal of Water and Environment Technology (ISSN:13482165)

巻号頁・発行日

vol.13, no.5, pp.383-394, 2015 (Released:2015-10-10)

参考文献数

16

被引用文献数

7

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Radioactive contamination resulting from the Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Station disaster following the Great East Japan earthquake and tsunami on March 11, 2011, has affected large areas of land in Fukushima, Japan. At present, agriculture has been limited to some areas, and there are concerns that radioactive substances carried by rainwater might contaminate water bodies such as ponds and rivers. In order to resume safe agricultural activities, evaluating the dynamics of radioactive substances in agricultural water is essential. In this study, we measured the concentration and analyzed the impact of radioactive cesium in irrigation water on rice in five districts having limited residential population. Further, we analyzed the radioactive cesium balance and soil samples from decontaminated paddy fields. The main findings of the study are (1) radioactive cesium in agricultural water was mainly in suspended form at the experimental locations within the 40 km zone; (2) most of the radioactive cesium in the irrigation water was accumulated in the paddy field, but radioactive cesium in irrigation water had limited impact on brown rice cultivation; and (3) continual monitoring of areas with radiation levels higher than those recorded in this study is recommended.

著者

Hiroshi Jinguji Yuki Fujiwara Kazuhisa Ohtsu Moono Shin Motoko Morimoto

出版者

The Japan Society of Medical Entomology and Zoology

雑誌

衛生動物 (ISSN:04247086)

巻号頁・発行日

vol.72, no.3, pp.199-204, 2021-09-25 (Released:2021-09-14)

参考文献数

49

被引用文献数

1

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The increase in the number of imported cases of dengue fever in Japan is of particular concern as Aedes albopictus is a vector of dengue fever. Due to the potential for insecticide resistance and the impact of insecticides on non-target species, increased attention is being paid to alternative methods of pest control. Placing salt in used tires has been recommended by the Ministry of Health, Labor and Welfare in Japan as a means of controlling mosquitoes. However, the effectiveness of salt as a larvicide against Ae. albopictus are currently unclear. This study examined the acute toxicity of sodium chloride against first and fourth larval instars of Ae. albopictus. Acute toxicity tests were conducted according to World Health Organization guidelines. The susceptibility of Ae. albopictus larvae was tested against 0.25%, 0.5%, 0.75%, 1.00%, 1.25% and 1.5% NaCl solutions. Larval mortality was correlated with an increase in NaCl concentration and exposure duration. First instar Ae. albopictus larvae were more sensitive to NaCl than fourth instar, and 72-h LC90 values for first and fourth larval instars were 0.49% and 1.01% NaCl, respectively. Our results suggest that the application of 0.5% NaCl to a habitat for 3 days is effective for Ae. albopictus control.