バングラデシュにおけるアルセンの移動と地下水の採掘

Charles F Harvey¹, Christopher H Swartz, A B M Badruzzaman

¹Ralph M. Parsons Laboratory, Department of Civil & Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 01239, USA.

Science (New York, N.Y.)

|November 26, 2002

まとめ

バングラデシュのヒ素中毒は,メタンの生産によって引き起こされる地下水への最近の炭素の流入に関連しています. 灌用ポンプは,ヒ素の動員を悪化させるが,有機炭素の注入は悪化させる.

科学分野:

環境科学環境科学
地質化学地質化学
水文地質学水文地質学は,水文地質学である.

背景:

井戸の水に含まれる高レベルのヒ素は,バングラデシュで広範な中毒を引き起こしています.
水層におけるヒ素の動員は,環境と健康に対する重大な懸念である.

研究の目的:

バングラデシュの水層におけるヒ素の動員における最近の炭素流入の役割を調査する.
バイオジオケミカルプロセスと灌ポンプのアルセニックレベルへの影響を理解する.
アルゼンチンの汚染を軽減するためのさまざまな介入の有効性を評価する.

主な方法:

バングラデシュ南部の典型的な水層からの化学および放射性炭素データの分析.
メラセス,窒素酸塩,低アルゼンチンの水を使用したフィールド注射実験.
濃度および関連する生地化学的パラメータのモニタリング.

主要な成果:

放射性炭素の若いメタンの高濃度は,最近の炭素が生地化学的プロセスを駆動していることを示しています.
灌用ポンプは,溶解したヒ素を最大限に含有する深さまで水を汲み上げることができます.
有機炭素またはその分解産物は,ヒ素を素早く動員することができます;酸化剤は濃度を下げることができます.

結論:

最近の炭素の流入,特に有機炭素とその分解産物からの流入は,ヒ素の動員に重要な役割を果たしています.
灌の慣行は,ヒ素曝露を高める可能性があります.
アクイファー素材は,アルセニックの吸収能力が限られており,代替緩和戦略の必要性を示唆しています.

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