Blood Response to Mercury Exposure in Athletic Horse From Messina, Italy

Mercury (Hg) exists in various chemical forms, and it is different to health effects. The most toxic effects occur in the central nervous system during fetal development with irreversible alterations of the nerve cells of the cerebral cortex and, it is essential to monitor the tissue residues of Hg to protect the animal's health. The present investigation was carried out during May 2019 in 20 horses located in equine sport center near the area of Milazzo, Messina, that is a part of Sicilian territory heavily polluted by many toxic substances. The purpose of this study was to determine the concentration of Hg in blood, serum, food, and water administered to horses and from the hematological profile as a biomarker of blood in relation to the bioaccumulation of Hg. The hematologic parameters (red blood cell, white blood cell, hemoglobin concentration, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and platelets) were processed with an automated hematology analyzer, and Hg concentrations were determined by DMA-80. To carry out the variation in the Hg levels in serum and blood, the data were subjected to paired t-test analysis; post-hoc comparisons were performed using Tukey's test. The differences were considered statistically significant when P < .05. Paired t-test showed that in blood samples, Hg concentrations were significantly higher than the serum, and blood samples were positively correlated with serum (r = 0.99; P < .0001). The Hg contents determined in blood, serum, hay, and water samples were below the respective benchmarks, and therefore, we can exclude any toxicological risk for athletic horse.