Researchers highlight the importance of studying the effects of combined metals in aquatic environments (image: CDMF)
Published on 02/26/2025
Agência FAPESP* – Researchers associated with the Center for Development of Functional Materials (CDMF) have been investigating the effects of different types of metals on marine organisms. Some of the results have been published in three recent papers.
The journal Marine Pollution Bulletin describes a study that evaluated the occurrence of synergism in 21 binary mixtures of the metals arsenic, cadmium, copper, iron, mercury, lead, and zinc and the effect of each mixture on colonies of Proales similis, an aquatic and microscopic animal species that makes up the so-called zooplankton.
The research identified synergisms in 20 of the 21 mixtures in one of the analyses (conducted with the model called TU50) and in 13 of the 21 in another analysis conducted with a more robust and complex tool (MIXTOX) for interpreting data from mixtures of compounds. The results point to the importance of reviewing the legal limits for the presence of each metal in water, since synergism amplifies their effects, even when each metal is present in a concentration lower than the established limits.
Another study, published in the journal Chemosphere, assessed the toxicity of zinc tungstate nanoparticles in a species of microalgae. This may be the first study of the toxicity of this semiconductor material in a eukaryotic organism (whose cells have a membrane-bound nucleus).
The results indicate that zinc tungstate is toxic to the microalga Raphidocelis subcapitata, specifically causing growth inhibition. This reinforces the need to monitor the presence of this material, which is also used in environmental remediation, in aquatic environments.
The microalga also appears in the article “Isolated and combined effects of cobalt and nickel on the microalga Raphidocelis subcapitata”, published in the journal Ecotoxicology.
The results showed that both metals alone altered the metabolism of the microalgae. Mixed together, they showed synergistic effects when the composition consisted of a low dose of nickel and a high dose of cobalt, and antagonistic effects when the composition contained a lot of nickel and little cobalt.
The researchers from the CDMF – a FAPESP Research, Innovation and Dissemination Center (RIDC) based at the Federal University of São Carlos (UFSCar) – emphasize the importance of studying the effects of combined metals in aquatic environments, since they may be different from their isolated effects. They also point out that microalgae are very sensitive organisms to contaminants and are at the base of the trophic chain, which means that any damage to them can affect higher trophic levels.
The article “Toxicity of binary-metal mixtures (As, Cd, Cu, Fe, Hg, Pb and Zn) in the euryhaline rotifer Proales similis: Antagonistic and synergistic effects” can be read at: www.sciencedirect.com/science/article/pii/S0025326X23012547.
The study “Effects of ZnWO4 nanoparticles on growth, photosynthesis, and biochemical parameters of the green microalga Raphidocelis subcapitata” is available at: www.sciencedirect.com/science/article/abs/pii/S0045653524004831.
And the article “Isolated and combined effects of cobalt and nickel on the microalga Raphidocelis subcapitata” can be accessed at: link.springer.com/article/10.1007/s10646-024-02728-0.
* With information from the CDMF.
Source: https://agencia.fapesp.br/54077
