Mercury concentration in Rutilus rutilus from the Caspian Sea and assessment of health risks

In order to determine the mercury content in muscle of roach (Rutilus rutilus) and its potential risks when consumed, samples of the fish were caught in two important fishing areas, Bandar Anzali and Bandar Torkaman. The mean concentration of mercury was 438 and 61 µg Kg-1 dw for Bandar Anzali and Bandar Torkaman, respectively. The maximum allowable fish consumption rates were respectively 0.57 Kg per week and 10.86 meals per month for Bandar Anzali and 2.74 Kg per week and 52.47 meals per month for Bandar Torkaman. Hazard quotient (HQ) values for fish samples in both regions were less than one. Correlation results showed no significant relationship between morphological parameters and mercury concentrations in muscle tissue in either region, although there was a significant negative correlation when the samples from both regions were pooled together. The concentrations of mercury in fish in both Bandar Anzali and Bandar Torkaman areas were lower than world standards. Overall, fortunately, the mercury levels in the fish were unlikely to have adverse effects on the health of fish or consumers, although continuous monitoring of contaminant levels is necessary due to the chemical properties of mercury and the frequent introduction of other contaminants into the waters in these areas.