Sixty percent of all US produced biosolids are land applied, and land application of animal manures has been widely practiced for centuries. Class B biosolids are known to contain bacterial and viral pathogens as well as protozoan parasites. Animal manures are reservoirs of E. coli and Cryptosporidium. In addition to this, both materials contain antibiotic resistant bacteria, endotoxin and pharmaceuticals including endocrine disruptors. The incidence of prions in these materials is currently unknown.  Proponents of land application claim that animal manures are organic and "good", and that biosolids are virtually safe enough to eat. Environmental activists, on the other hand, claim that if you come into contact with biosolids that you are likely to die. The truth, of course, lies somewhere in between, and depends on the management strategies of land application. The overall risk of biologicals to communities close to land application sites depends on the fate and transport of the biologicals through air, or through soil to groundwater. In this paper, routes of exposure of microbials and bio chemicals during and following land application will be discussed. In addition, other common sources of these existing and emerging contaminants will be presented to allow for an examination of the relative risk of the contaminants, and their potential impact on human health and welfare.