Wh. Gutenmann et al., ELEMENTS AND POLYCHLORINATED-BIPHENYLS IN SEWAGE SLUDGES OF LARGE CITIES IN THE UNITED-STATES, Chemosphere, 28(4), 1994, pp. 725-728
An analytical survey was conducted of sewage sludges from 16 large cit
ies in the United States for toxic and nutrient elements and polychlor
inated biphenyls. The Cd content of one sludge (242 ppm) was far above
that recommended if the sludge is to be applied to agricultural land.
The content of Ni or Zn in four other sludges was only slightly below
permissible levels for those metals. Continuous analytical monitoring
of toxicant levels in sludges is recommended.