探討受鎵或銦污染之水田土壤對稻田魚的急毒性
Other Title
Assessing Acute Toxicity of Gallium- or Indium-Contaminated Paddy Soils in Rice-Fish
Journal
土壤及地下水污染整治
Journal Volume
7
Journal Issue
2
Start Page
69
End Page
79
ISSN
2313-2736
Date Issued
2022
Author(s)
藍呂陞(Lu-Sheng Lan)
Abstract
鎵（gallium, Ga）與銦（indium, In）為新興污染物質，其化合物被大量使用於半導體及光電產業，因而經常隨著放流水不當排放而提高水田土壤被污染的風險。然而目前尚無相關的土壤污染管制標準，鎵或銦經由土壤污染之暴露途徑對人體或環境造成的危害風險仍不明確。本研究旨在利用俗稱為稻田魚的青鱂魚（Oryzias latipes, medaka）為模式生物，建立土壤－水－魚之生物暴露系統，以評估受鎵或銦污染之水田土壤對生物的急毒性（7日死亡率）。結果顯示，暴露於高鋁含量酸性土壤之幼魚死亡率隨著土壤中鎵或銦的濃度上升而顯著增加，而低鋁含量中性土壤則不會造成暴露之幼魚死亡。青鱂魚幼魚的7日半數致死量與覆蓋水中鋁含量高度相關，故造成急毒性的主因為鎵或銦進入土壤後，置換土壤結構中鋁而使覆蓋水中鋁含量上升所致。本研究以水田土壤生物暴露系統及青鱂魚評估鎵或銦污染土壤之生態毒性，並期望此方法可應用於水稻田污染之生態監測與風險評估。
Gallium (Ga), indium (In), and associated compounds are often used in the semiconductor and optoelectronic manufacturing industries. They frequently pollute paddy soils owing to the improper discharge of runoff water and are considered as emerging contaminants (ECs). Currently, the risk and toxic impact of Ga, In, or any other ECs on human health and environmental safety remains unclear. In this study, a soil-water-fish exposure system was established using rice fish larvae (Oryzias latipes, medaka), as a model organism. The purpose of this study was to investigate the acute toxicity by studying 7-day mortality of Ga- or In-contaminated paddy soil exposed to aquatic organisms. The results indicated that mortality of treated larvae was directly proportional to concentrations of Ga or In in acidic soils with high aluminum (Al) content while neutral soils with low Al content contaminated with these two ECs did not cause a significant effect on the exposed larvae. The 7-day lethal concentration at 50% of maximum mortality (7d-LC_(50)) of medaka exposed to contaminated soils was found to have a high correlation with Al content in the overlying water. Therefore, the acute toxicity of exposed fish can be ascribed to Al-induced mortality as spiked Ga or In can replace Al in the soil structure, thereby augmenting the Al content in the overlying water. Overall, this study suggests a new strategy to evaluate the environmental risks of Ga or In contamination in paddy fields using a soil-water-fish exposure system and medaka fish.
Subjects
水田土壤
青鱂魚
新興污染物質
銦
鎵
emerging contaminants (ECs)
gallium (Ga)
indium (In)
medaka fish (Oryzias latipes)
paddy soils
Type
journal article