Trace element levels in tissues from cattle fed a sewage sludge-amended diet.

The levels of 20 elements (Al, Ca, Cd, Cl, Co, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, Sb, Se, V, and Zn) are reported for kidney, liver, muscle, spleen, and brain tissues taken from two groups of six steers per group in a feeding study conducted at Colorado State University. The control group was fed a normal feedlot cattle ration and the test group was fed the same ration amended with 12% (by weight) air-dried municipal sewage sludge. Elemental levels are also reported for the control and test diets, control and test feces, and sewage sludge added to the diet. All samples were analyzed by inductively coupled plasma emission spectroscopy and neutron activation analysis. Brief descriptions of the analytical methods are included. The levels of all metals determined were elevated in the test diet (as much as 19-fold for Cd) compared with the control diet. The levels of Pb and Cd in kidney and of Pb, Cd, and Cu in liver in the test animals were high enough to cause concern from a toxicological standpoint if these tissues were consumed regularly by humans. None of the levels of any of the other elements in the control and test animal tissues were high enough to cause similar concern with respect to human consumption.