著者
石川 百合子 川口 智哉 保高 徹生 東野 晴行
出版者
公益社団法人 日本水環境学会
雑誌
水環境学会誌 (ISSN:09168958)
巻号頁・発行日
vol.37, no.2, pp.29-43, 2014 (Released:2014-03-10)
参考文献数
27
被引用文献数
2 1

本研究では2011年3月の福島第一原発事故により放出された放射性セシウムによる河川流域における河川水濃度と流域土壌に蓄積した量(本論文では,蓄積量と表記する)の残存状況の推定を目的とした数値シミュレーションモデルを構築した。産総研-水系暴露解析モデル(AIST-SHANEL)をプラットフォームとし,流域における懸濁物質の流出ポテンシャルと放射性セシウムの動態を考慮したモデルを導入し,阿武隈川水系を対象にケーススタディーを実施した。その結果,本モデルの妥当性を検証し,降水による出水に伴う放射性セシウムの総流出量は僅かであることが示された。特に,セシウム137は自然崩壊が少ないことも相まって流域における蓄積量を減少させるのは困難なことが考えられ,除染をはじめ総合的な対策を検討することの必要性が示唆された。本モデルは放射性セシウムの河川流域での挙動解析や汚染対策の評価を可能にするものと考えられる。
著者
岩崎 雄一 村田 道拓 川口 智哉 松本 親樹 保高 徹生
出版者
一般社団法人 資源・素材学会
雑誌
Journal of MMIJ (ISSN:18816118)
巻号頁・発行日
vol.138, no.3, pp.28-32, 2022-03-31 (Released:2022-03-29)
参考文献数
26
被引用文献数
2

For a total of 80 legacy mines in Japan, by assuming that untreated mine drainages were discharged and that metal loadings from sources other than mine drainage were negligibly small, we estimated seven element concentrations (Cd, Pb, As, Cu, Zn, Fe, and Mn) at water quality monitoring (WQM) river sites closest to individual mines (hereinafter referred to as the closest WQM sites) based on a simple dilution approach. In addition, for zinc as an example, the concentrations at the closest WQM sites were estimated by taking account into estimated zinc loadings from sources other than mine drainage. Results of the former analysis showed that the concentrations of all four elements (Cd, Pb, As, and Zn) at the closest WQM sites were predicted to be below Japanese environmental water quality standards in 50% of the legacy mines analyzed, which is not a small percentage. However, the result of the latter analysis showed that the contributions of treated mine drainages to the total loadings of zinc at the closest WQM sites were less than 50% in approximately 88% of the legacy mines analyzed. This result suggests that metal loadings from sources other than mine drainages at the closest WQM sites are not trivial in many legacy mines. Even if untreated mine drainages were discharged, estimated zinc concentrations in 72% of the WQM sites, where the annual average of measured concentrations of total zinc was below the environmental water quality standard (0.03 mg/L), were still below the standard. Despite a screening-level assessment based on multiple assumptions such as the simple dilution, results of the present study should be valuable for understanding the impact of discharging untreated mine drainages on metal concentrations in rivers receiving those from the legacy mines toward applying the water-quality management that secures the protection of downstream water use.