Multi-year study monitoring the mercury content in the tissues of cattle sampled in the Czech Republic between 2014 and 2023

Analyses of mercury concentrations in the muscle, liver and kidneys of cattle were conducted in the Czech Republic during the period from 2014 to 2023. The average mercury content in muscles, livers, and kidneys of calves was 0.000 5 ± 0.000 0 mg.kg^-1, 0.002 7 ± 0.000 5 mg.kg^-1, and 0.004 1 ± 0.000 8 mg.kg^-1, respectively. In fattening cattle, the average mercury content in muscles, livers and kidneys was 0.000 5 ± 0.000 0 mg.kg^-1, 0.002 1 ± 0.000 2 mg.kg^-1 and 0.004 9 ± 0.000 3 mg.kg^-1, respectively. In cows, the average mercury content in muscles, livers and kidneys was 0.000 5 ± 0.000 0 mg.kg^-1, 0.002 3 ± 0.000 1 mg.kg^-1 and 0.006 9 ± 0.000 3 mg.kg^-1, respectively. The maximum residual limit for human consumption was exceeded in 10 kidney samples (3 calves, 6 cows, 1 fattening cattle) and 1 liver sample (calf). In all age categories, the highest mercury concentrations were found in the kidneys, lower in the livers, and the lowest in the muscles. When comparing the age groups, significantly higher mercury concentrations were observed in the kidneys of cows than in calves and fattening cattle. It can be concluded that there is still a need for further monitoring of mercury concentrations in cattle tissues in the Czech Republic.