Effects of Zinc Smelting Waste Slag Treated with Root Organic Acids on the Liver of Zebrafish (Danio rerio)

Vegetation reconstruction was widely adopted for the waste slag site. But the toxic elements may be made public from slag due to the organic acid secreted by plant roots, which will pollute the surrounding environment and harm human health. The purpose of the study was to evaluate the harm of toxic substances released from zinc (Zn) smelting waste slag to zebrafish. The effect was simulated by adding organic acid to slag, and the toxicity of the slag was evaluated through the enzyme activity, genetic toxicity, tissue sections of zebrafish liver tissue. The results showed that more heavy metals were made public from the slag, as the concentration of organic acids increased. Exposure to toxic substances for 14 days, the antioxidant enzyme activities, termed as superoxide dismutase (SOD) and catalase (CAT), were significantly affected, which caused obvious malondialdehyde (MDA) accumulation. A comet assay revealed dose-dependent DNA damage in hepatocytes. Depending on the histopathological analysis, atrophy and necrosis of cells and increased hepatic plate gap were observed. The obtained results highlighted that toxic substances from slag may be deleterious to zebrafish.