Abstract
Organisms are frequently exposed to mixtures of heavy metals because of their persistence in the environment. The mixture toxicity of heavy metals should therefore be evaluated to perform a rational environmental risk assessment for organisms. In this study, we determined the inhibition toxicity of five heavy metals (Cu2+, Co2+, Zn2+, Fe3+ and Cr3+) and their binary mixtures to Photobacterium phosphoreum (P. phosphoreum). We obtained the following results: (1) the order of individual toxicity was Zn2+>Cu2+>Co2+>Cr3+>Fe3+, and (2) different combined effects (additive, synergistic and antagonistic) were observed in the binary mixtures of heavy metals, with toxicity unit (TU) values ranging from 0.15 to 3.50. To predict the mixture toxicity of heavy metals, we derived the ion characteristic parameters of heavy metal mixtures and explored the ion-characteristic-based quantitative structure–activity relationship (QSAR) model (R2 = 0.750, Q2 = 0.649). The developed QSAR model indicated that the mixture toxicity of heavy metals is related to the change in ionization potential ((ΔIP)mix), the first hydrolysis constant (log(KOH)mix) and the formation constant value ().
Highlights
Organisms are typically exposed to mixtures of heavy metals because of these metals’ persistence in the environment and common use in society [1]
The objectives of this study are to (1) determine the acute (15-min exposure) toxicity to P. phosphoreum of single heavy metals and their binary mixtures at different concentrations, (2) develop a robust and predictive quantitative structure– activity relationship (QSAR) model based on the characteristics of heavy metal ions, and (3) reveal the possible mixture toxicity mechanism based on the developed QSAR model
On the basis of the toxic effects of the individual antibiotics (EC50), we evaluated the toxicity of binary mixtures (-logEC50M) at the equitoxic levels
Summary
Organisms are typically exposed to mixtures of heavy metals because of these metals’ persistence in the environment and common use in society [1]. Compared with individual toxicity results, mixture toxicity data are certainly better for performing a comprehensive evaluation of the combined toxicological effects of heavy metal mixtures upon organisms [2,3]. The median effective inhibition concentrations (EC50) of five heavy metals on freshwater ciliated protists mostly range from 0.01 to 1.00 mg/L [6]. Heavy metal ions were shown to be severely cytotoxic to fish cell lines [7].
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
