Heavy elements in the environment and their impacts on human health

Over recent years, a great efforts have been directed toward quantification of human exposure to heavy metals. Many questions arised concerning their presence in air, water, plants and food chain. Information concerning heavy metals distribution in the environment, uptake by plants and relationships with human health is still lacked in our country, despite that some of them are toxic to human in low concentrations, while others may be toxic to plants. Also many of heavy elements accumulate in plants and human organs. This study aims at highlighting the sources of some heavy elements, their concentrations in the ecosystem components (Water, air, soil and plants), and their effects on human health, in addition to the allowable concentrations of such elements in air, soil, water and plants. (author)