TY - JOUR
T1 - Interactions of arsenic, copper, and zinc in soil-plant system
T2 - Partition, uptake and phytotoxicity
AU - Gong, Bing
AU - He, Erkai
AU - Qiu, Hao
AU - Van Gestel, Cornelis A.M.
AU - Romero-Freire, Ana
AU - Zhao, Ling
AU - Xu, Xiaoyun
AU - Cao, Xinde
PY - 2020/11/25
Y1 - 2020/11/25
N2 - 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.
AB - 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.
KW - Interaction
KW - Metal(loid)
KW - Mixture toxicity
KW - Modeling
KW - Soil
UR - http://www.scopus.com/inward/record.url?scp=85088360440&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85088360440&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2020.140926
DO - 10.1016/j.scitotenv.2020.140926
M3 - Article
AN - SCOPUS:85088360440
VL - 745
SP - 1
EP - 10
JO - Science of the Total Environment
JF - Science of the Total Environment
SN - 0048-9697
M1 - 140926
ER -