Genotoxicity and cytotoxicity response to environmentally relevant complex metal mixture (Zn, Cu, Ni, Cr, Pb, Cd) accumulated in Atlantic salmon (Salmo salar). Part I: importance of exposure time and tissue dependence

Abstract

Health impact of metal mixture at environment realistic concentrations are difficult to predict especially for long-term effects where cause-and-effect relationships may not be directly obvious. This study was aimed to evaluate metal mixture (Zn-0.1, Cu-0.01, Ni-0.01, Cr-0.01, Pb-0.005 and Cd-0.005 mg/L, respectively for 1, 2, 4, 7, 14 and 28 days at concentrations accepted for the inland waters in EU) genotoxicity (micronuclei, nuclear buds, nuclear buds on filament), cytotoxicity (8-shaped nuclei, fragmented-apoptotic erythrocytes), bioaccumulation, steady-state and the reference level of geno-cytotoxicity in hatchery-reared Atlantic salmon tissues. Metals accumulated mostly in gills and kidneys, to the lesser extent in the muscle. Uptake of metals from an entire mixture in the fish for 14 days is sufficient to reach steady-state Cr, Pb concentrations in all tissues; Zn, Cu-in kidneys and muscle, Ni-in liver, kidneys, muscle and Cd-in muscle. Treatment with metal mixture significantly increased summed genotoxicity levels at 7 days of exposure in peripheral blood and liver erythrocytes, at 14 days of exposure in gills and kidney erythrocytes. Significant elevation of cytotoxicity was detected after 2 and 14 days of exposure in gills erythrocytes and after 28 days-in peripheral blood erythrocytes. The amount of Cu, Cr, Pb and Cd accumulated in tissues was dependent upon duration of exposure; nuclear buds, 8-shaped nuclei frequencies also were dependent upon duration of exposure. This study indicates that metals at low levels when existing in mixture causes significant geno-cytotoxicity responses and metals bioaccumulation in salmon.

Effect of organic and in-organic chromium supplementation on growth performance and genotoxicity of Labeo rohita

“…Interaction of carbohydrates with other elements is directly correlated to fish health. Cr has been investigated as cytotoxic element causing genotoxicity in fish liver and blood (Stankiviciute et al, 2017). Cr exposure has been shown to cause DNA strand breakage and formation of Cr-DNA complex including Cr-DNA adducts and DNA-Cr-DNA crosslinks.…”

Zinc Chloride Exposure Inhibits Brain Acetylcholine Levels, Produces Neurotoxic Signatures, and Diminishes Memory and Motor Activities in Adult Zebrafish

“…Zinc was found as an environmental hazard in at least 985 of the 1662 waste sites proposed by the Environmental Protection Agency (EPA) National Priorities list [ 14 ]. The toxicity by zinc was reported in several fish species [ 15 , 16 , 17 ]. It was well documented that zinc induced embryological damage in red sea bream Pagrus major , including alterations in fecundity, low hatching rate, and high mortality [ 18 ].…”

Genotoxic effect of heavy metals on Astyanax lacustris in an urban stream

“…Pb can interfere with the DNA repair system by inhibiting enzyme activity ( Zhang et al., 2019 ). Despite the individual effects of those elements on the genetic level, we highlight that combined metals, associated with the ambient condition, can increase toxic effects when compared to isolated chemicals ( Stankevičiūtė et al., 2017 ). However, we recognize that this study evaluated acute toxicity responses, requiring additional work to understand the prolonged effects on the water bodies.…”