1 Department of Environmental Engineering, Faculty of Natural Resources and Environment, University of Birjand, Birjand, Iran

2 University of Michigan, P.O. Box 7038, Ann Arbor, MI, USA


BACKGROUND AND OBJECTIVES: The nanoparticles has been discussed in terms of their adverse global impacts on health and health inequity. Metal oxide nanoparticles and their salts can have varied toxic effects on different tissues in the aquatic environments. The aim of present study was to assess the toxicity of nickel oxide nanoparticles in relation to different nickel salts.
METHODS: Acute toxicity of nickel oxide nanoparticles, nickel sulfate, nickel nitrate and nickel chloride, in black fish was investigated. A total of 125 fish were randomly assigned to a control group (n=25) and four exposure groups (n=25 per group). After 28 days of exposure, the bioaccumulation of nickel oxide nanoparticles in gill, intestine, liver, and kidney of the fish was determined by killing half of them in each group and dissecting their tissues. The remaining fish were placed in clean water for another 28 days and the depuration rate was estimated.
FINDINGS: The LC50-96 values reported for nickel oxide nanoparticles, nickel sulfate, nickel nitrate and nickel chloride were 195, 120, 138 and 91 milligrams per liter, respectively. Therefore, nickel chloride had a higher toxicity compared to nickel oxide nanoparticles, nickel sulfate and nickel nitrate. The highest rate of nickel oxide nanoparticles bioaccumulation was observed in the gill (0.40±0.08 microgram per gram), intestine (41.82±16.95 microgram per gram), liver (2.16±1.82 microgram per gram), and kidney (2.16±1.26 microgram per gram) of the fish. The highest depuration rate of nickel oxide nanoparticles, nickel sulfate, nickel nitrate, and nickel chloride was recorded in the intestinal tissue of the fish. The lowest depuration rate of nickel oxide nanoparticles, nickel sulfate and nickel nitrate was observed in the kidney tissue of the fish. Also, the lowest depuration rate of nickel chloride was witnessed in the gill tissue of the fish. Histopathological anomalies were detected in the fish exposed to nickel oxide nanoparticles. These anomalies were fusion of lamellae, lamellar synechiae, curvature and oedema in the gill; increased number of goblet cells and cell swelling; and degradation of villi structure and expansion of villi structure in the intestine.
CONCLUSION: The study conclusively demonstrated that nickel oxide nanoparticles were eco-toxic and harmful to aquatic organisms. Strong global nickel oxide nanoparticles regulations must be enforced to prevent further environmental contamination with nanoparticles.

Graphical Abstract

Toxicity of nickel oxide nanoparticles in Capoeta fusca, using bioaccumulation, depuration, and histopathological changes


  • NiCl2 (LC50: 91.20 mg/L) was more toxic than NiSO4 (LC50: 120.22 mg/L), Ni (NO3)2 (LC50: 138.03 mg/L), and NiO NPs (LC50: 194.98 mg/L) for a period of 96 h;
  • NiCl2 caused the most damage to the tissues of the gills and intestines of black fish;
  • The highest and lowest levels of Ni accumulation in different tissues were related to NiO NPs and NiCl2 respectively;
  • The maximum BCF in gill, intestinal and liver tissues was ordered as NiCl2 > Ni (NO3)2 > NiSO4 > NiO NPs, respectively, and in kidney tissue followed the order of Ni (NO3)2 > NiCl2 > NiSO4 > NiO NPs, respectively.


Main Subjects


©2023 The author(s). This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third-party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit:


GJESM Publisher remains neutral concerning jurisdictional claims in published maps and institutional affiliations.


Google Scholar Scopus Web of Science PlumX Metrics Altmetrics Mendeley |


GJESM Publisher

Letters to Editor

GJESM Journal welcomes letters to the editor for the post-publication discussions and corrections which allows debate post publication on its site, through the Letters to Editor. Letters pertaining to manuscript published in GJESM should be sent to the editorial office of GJESM within three months of either online publication or before printed publication, except for critiques of original research. Following points are to be considering before sending the letters (comments) to the editor.

[1] Letters that include statements of statistics, facts, research, or theories should include appropriate references, although more than three are discouraged.
[2] Letters that are personal attacks on an author rather than thoughtful criticism of the author’s ideas will not be considered for publication.
[3] Letters can be no more than 300 words in length.
[4] Letter writers should include a statement at the beginning of the letter stating that it is being submitted either for publication or not.
[5] Anonymous letters will not be considered.
[6] Letter writers must include their city and state of residence or work.
[7] Letters will be edited for clarity and length.