Exposure of industrial and environmental toxic substances to air, drinking water, soil, plants, animals and food chains and their continuous release to the human environment have a negative impact on human health. When exposed to heavy metals due to these toxic exposures, many effects on body functions can occur. Generally, due to the long half-life of the metal in the body, it can accumulate biologically in soft and hard tissues/organs. Bone tissue undergoes a continuous remodeling throughout life. This involves the simultaneous action of resolution, synthesis and mineralization of the bone matrix. In general, metals have two effects on bone tissue: the first is their direct toxicity to bone cells and the second is their accumulation in the bone matrix. Their direct toxicity mainly affects osteoblasts, inhibits osteoblast differentiation, synthesis activity and mineralization of the extracellular matrix. Their effect on osteoclasts differs from that of metal, increases or decreases the activity of tartarate resistant acid phosphatase enzyme and prevents the maturation of the precursors. As a result, it causes imbalance in the bone remodeling process, reduces bone formation and contributes to the formation of bone diseases such as osteopenia and osteoporosis. Despite our knowledge of the effect of metals on bone tissue, many things are still unclear. Understanding the mechanisms of action will ensure that appropriate therapies are available to address their adverse effects on bone tissue. 

Keywords: Heavy metal; Bone; Osteoporosis.