ABSTRACT
Heavy metal contamination is derived from numerous sources, including the mining and smelting of nonferrous metals; metals emitted from these industries have been shown to accumulate in soil and vegetation in the vicinity of the industry (Buchauer, 1973; Helmisaari et al., 1995). This often leaves the surrounding areas derelict and devoid of vegetation. With the intensification of agriculture, there has been an increase in the addition of inorganic and organic manures in an attempt to maximize crop production. The addition of organic wastes and fertilizers based on sewage sludge, pig and poultry wastes may also add high levels of copper, zinc, and cadmium. Three such examples of heavy metal contamination are used to determine the effect of elevated soil metals on the pigment profiles of Torreya californica and T. nucifera.
