Management of Sludge Use on Land

Abstract
Passage of the Federal Water Pollution Control Act in 1972 has caused a huge increase in the amount of sewage sludge for disposal. The Food and Drug Administration has worked with the Environmental Protection Agency and other agencies to recommend proper management of the application of sludges to food and feed crops to ensure the safety and wholesomeness of the food supply. FDA's concerns about contamination of food by pathogenic microorganisms, heavy metals, persistent pesticides and industrial chemicals such as polychlorinated biphenyls (PCBs) are described. The reasons for special concern about direct application of sludge onto growing food and feed crops are discussed. The estimated daily intake of lead and cadmium, as compared to the proposed tolerable daily intakes, is presented, together with FDA's program to develop sufficient data on the natural background levels of these metals in raw agricultural products. Limitations recommended to prevent hazardous cadmium, lead, PCB and pathogen contaminati...