Abstract
Arsenic, copper, and zinc are common elements found in contaminated soils but little is known about their combined effects on plants when presented simultaneously. Here, we systematically investigated the phytotoxicity and uptake of binary and ternary mixtures of As, Cu, and Zn in a soil-plant system, using wheat (Triticum aestivum) as model species. The reference models of concentration addition (CA) and response addition (RA) coupled with different expressions of exposure (total concentrations in soil ([M]tot, mg/kg), free ion activities in soil solution ({M}, μM), and internal concentrations in plant roots ([M]int, μg/g)), were selected to assess the interaction mechanisms of binary mixtures of As–Cu, As–Zn, and Cu–Zn. Metal(loid) interactions in soil were estimated in terms of solution-solid partitioning, root uptake, and root elongation effects. The partitioning of one metal(loid) between the soil solution and solid phase was most often inhibited by the presence of the other metal(loid). In terms of uptake, inhibitory effects and no effects were observed in the mixtures of As, Cu, and Zn, depending on the mixture combinations and the dose metrics used. In terms of toxicity, simple (antagonistic or synergistic) and more complex (dose ratio-dependent or dose level-dependent) interaction patterns of binary mixtures occurred, depending on the dose metrics selected and the reference models used. For ternary mixtures (As-Cu-Zn), nearly additive effects were observed irrespective of dose descriptors and reference models. The observed interactions in this study may help to understand and predict the joint toxicity of metal(loid)s mixtures in soil-plant system. Mixture interactions and bioavailability should be incorporated into the regulatory framework for accurate risk assessment of multimetal-contaminated sites.
Original language | English |
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Article number | 140926 |
Pages (from-to) | 1-10 |
Number of pages | 10 |
Journal | Science of the Total Environment |
Volume | 745 |
Early online date | 17 Jul 2020 |
DOIs | |
Publication status | Published - 25 Nov 2020 |
Funding
This study was supported by the National Natural Science Foundation of China (No. 41701571 , No. 41701573 , No. 41877500 , and No. 41977115 ), Shanghai Rising-Star Program (No. 20QA1404500 ), the National Key Research and Development Program of China (No. 2018YFC1800600 , No. 2018YFD0800700 ), the Research Fund Program of Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (No. 2018K01 ), Science and Technology Program of Guangzhou, China (No. 201904010116 ), Fundamental Research Funds for the Central Universities (No. 19lgpyl50 ), and the Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, Ministry of Agriculture/Tianjin Key Laboratory of Agro-environment and Safe-product (No. 17Z1170010019 ).
Funders | Funder number |
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Ministry of Agriculture/Tianjin Key Laboratory of Agro-environment and Safe-product | 17Z1170010019 |
National Natural Science Foundation of China | 41701571, 41701573, 41877500, 41977115 |
Guangzhou Science and Technology Program key projects | 201904010116 |
Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology | 2018K01 |
National Key Research and Development Program of China | 2018YFD0800700, 2018YFC1800600 |
Fundamental Research Funds for the Central Universities | 19lgpyl50 |
Shanghai Rising-Star Program | 20QA1404500 |
Key Laboratory of Original Agro-Environmental Pollution Prevention and Control |
Keywords
- Interaction
- Metal(loid)
- Mixture toxicity
- Modeling
- Soil