Lead (Pb) and cadmium (Cd) are now recognized to be two of most important heavy metal contaminants in the environment. Due to their increased industrial uses and environmental pollution with the related waste products, concentrations of lead and cadmium are increasing rapidly in the environment in recent years. Since the two elements are often released simultaneously in the environment from a number of natural and man made sources, adverse health effects caused by combined exposure to lead and cadmiu...