Chromium-induced micronuclei in fish

Area of Science:

• Environmental toxicology
• Aquatic toxicology
• Genetics

Background:

• Leather waste discharge introduces chromium (Cr(VI) and Cr(III)) into aquatic environments.
• Chromium is a heavy metal pollutant with known toxic effects.
• Prussian carp (Carassius auratus gibelio) are a common freshwater fish species.

Purpose of the Study:

• To investigate the cytogenetic effects of Cr(VI) and Cr(III) on Prussian carp.
• To assess chromium-induced genotoxicity in fish erythrocytes.
• To evaluate chromium contamination in the Ljubljanica River.

Main Methods:

• Micronuclei induction assay in fish erythrocyte cells was used to detect cytogenetic damage.
• Fish were sampled from the Ljubljanica River at sites above and below leather waste discharge.
• Laboratory experiments involved exposing fish to sub-lethal concentrations of Cr(VI) and Cr(III).

Main Results:

• Exposure to both Cr(VI) and Cr(III) led to a significant increase in micronuclei frequency in fish erythrocytes.
• Elevated micronuclei levels were observed in fish from both field and laboratory exposure conditions compared to controls.
• The study confirmed a dose-dependent relationship between chromium concentration and cytogenetic damage.

Conclusions:

• Chromium contamination, from sources like leather waste, induces significant cytogenetic damage in Prussian carp.
• The micronucleus test is a reliable biomarker for assessing chromium genotoxicity in aquatic organisms.
• Monitoring chromium levels and their effects on fish is crucial for managing riverine ecosystem health.