ABSTRACT
Animals are at the interface between environment and human health because they are the nal receptors of environmental contaminants and the providers of contaminants for humans through the consumption of their products. Edible animal by-products can concentrate heavy metals as a result of the environmental pollution of air, soil, and water and the contamination from agricultural practices and animal feeding. The heavy metals of particular concern are arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg), in relation to their harmful effects on human health and their known bioaccumulation property. The inorganic As (As(3) and As(5) forms) is more hazardous to humans than the organic As, and it is primarily of concern because of its cancer-causing properties. The chronic low-level As exposure gives skin, vascular, and nervous system disorders [1,2]. Cadmium causes renal and lung damages and negative effects on hemopoietic, cardiovascular, and skeletal systems [3,4]. Organic Hg compounds, usually methylmercury (MeHg), are more harmful than inorganic Hg, and they have been implicated in brain and liver damages [5]. Shortterm Pb exposure adversely affects the brain and induces anemia and gastrointestinal symptoms [6].
