Accumulation of Toxic Elements in Bone and Bone Marrow of Deer Living in Various Ecosystems. A Case Study of Farmed and Wild-Living Deer

Abstract

The aim of the study was to determine the concentrations of toxic elements accumulated in the bone marrow and bones (Cervus elaphus). The studies were carried out on two groups of young stags: farmed (n = 6) and wild (n = 9). Their body weights were measured and bone and bone marrow samples were collected. The concentrations of toxic elements were analyzed using the inductively coupled plasma mass spectrometry technique. The mean aluminum content in the bone marrow and bones of the farmed animals was significantly higher than in the wild group (p < 0.05). The mean concentration of arsenic, barium and lead in the bones of the wild red deer was significantly higher than in the bones of the farmed animals (p < 0.05), while the cadmium concentration in the bones of the farmed red deer exceeded the value determined in the wild animals. A significant difference was found between the mean concentrations of aluminum, arsenic, barium, lead, vanadium and nickel in the bone marrow and bones of both red deer groups (p < 0.05). Although the study involved animals living in an uncontaminated area, the concentrations of some heavy metals were higher than values reported from industrial regions.

The Mineral Composition of Bone Marrow, Plasma, Bones and the First Antlers of Farmed Fallow Deer

“…When comparing soft tissues, higher concentrations of Ca, P, Mg, Cr, Zn, Se, Al, Ba and Ni in bone marrow than in plasma were demonstrated. This research also confirms our previous study on the translocation of minerals within the body and depending on the consumed food and metabolic changes [ 8 , 15 ] due to the fact that blood does not accumulate minerals but only transports them and reflects their amount at a given time. Blood is a tissue with a high renewal rate due to the physiologically short life span of cells in the circulation.…”

“…In the studies of Hassan et al [ 16 ] on the bone marrow of reindeer, evidence of Cd, Pb, and As was demonstrated, and in the presented studies in fallow deer, the content of these elements was below the detection level. In the bone marrow of farmed and wild red deer living in the same area [ 8 ], higher concentrations of As, Ba, Pb and Ni were found only in wild animals (0.008 mg/kg, 0.969 mg/kg, 0.003 mg/kg, 0.042 mg/kg, respectively), while lower Al levels (2.638 mg/kg) and the same levels of Be, Cd, Sb (<LOD) and Ni (0.014 mg/kg) were found in farmed red deer compared to with fallow deer. The described differences in the concentrations of individual bulk, trace and toxic elements may result from differences between species, but they may also be caused by the different ages of the tested animals and the potential for assimilation of individual elements resulting from individual characteristics.…”

“…Chemical analyzes of element determinations were performed in accordance with the descriptions contained in previous publications [ 6 , 7 , 8 , 14 ]. Briefly, the mineral concentrations in the tissues of fallow deer were determined by the aqua regia digestion (sample weight of 0.5 g) with a microwave digestion (Mars Xpress from CEM Corp., Matthews, NC, United States).…”

“…The bone marrow of young animals consists largely of hematopoietically active tissue (from immature cells which can develop into all types of blood cells), with relatively little fat. In these animals, all cells of the body, especially blood, are formed primarily in the bone marrow and are then distributed in the blood throughout the body [ 8 ]; however, blood is not an indicator of an adequate supply of all minerals, only showing their content in the moment. Moreover, haematopoiesis is a process that is highly consuming due to the rapid turnover of the haematopoietic system and consequent demand for nutrients and dependence on highly specialised bone marrow.…”

“…They have access to permanent pastures and are fed with properly balanced fodder, especially in winter; therefore, they should be free from toxic substances. Despite this, studies on farmed red deer have shown the accumulation of hazardous substances in their tissues [ 8 ].…”