Sewage sludge as an uncalled for product of wastewater treatment poses the challenge to society of disposing of it. Application of sewage sludge to agricultural land may be beneficial because it can improve the physical, chemical and biological properties of soils which may enhance crop growth. While, sewage sludge contains various heavy metals and it contains a wide variety of pathogens and can be infectious for different species of animals and plants as well as for humans. Consequently environmentally sound decisions need to be based on an integrative evaluation of contaminant sources and...