1988 EPA Study Occurrence of Pathogens in Distribution and Marketing Municipal Sludges William A. Yanko, County Sanitation Districts of Los Angeles County, "Although the use of sludge as a soil amendment is attractive, it is not without potential health risks. Toxic chemicals, including heavy metals and industrial organics, may enter the food chain and present long-term health risks."
significant increases in bacterial populations, including salmonellae, occurred during subsequent production of commercial s o i l amendment products.
Efforts to characterize major unknown organic components were limited to computer comparisons of GC/MS peaks to the NBS mass spectral library. In none of the cases was a tentative identification made. Manual review of those components with a high degree of fit with an NBS library compound (>8O%) allowed probable compound class assignment for many peaks. Virtually all of the major components classified appeared to be aliphatics or carboxylic acid type compounds. A majority of the sample extracts exhibited a hydrocarbon "hump" in the ion chromatograms. The peaks reviewed, therefore, were superimposed on this background. As a result,a significant portion of the major peaks were multi-component peaks whose identities remain completely unknown.