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Hormones such as 17-β-estradiol (E2), estrone (E1) and testosterone constitute an important class of endocrine disrupting chemicals (EDCs) and thus their presence in the environment is of great concern. Land application of estrogen-containing solid wastes (animal manure) is considered a major entry pathway of these EDCs to natural water bodies via surface runoff and/or leaching (Baronti et al., 2000). Transformations of these hormones in soil impact their presence in water bodies (Casey et al., 2005). Previous studies show that extracellular enzymes are capable of transforming persistent chemicals into non-harmful products (Auriol et al., 2007, Fan et al., 2007), indicating that enzymes produced by microorganisms may play an important role in humification of hormones. This study aims towards better understanding of transformation pathways in soils and the contribution of enzymes (Horseradish Peroxidase and Lignin Peroxidase) in humification of hormones and will be conducted in three different tasks. Soils preloaded with 14C-labeled hormones will be treated with different levels of enzymes and co-substrates and the products will be analyzed using liquid scintillator, HPLC, and LC/MS/MS. The transformation of 14C-labeled hormones will also be studied in systems where fungi that produce humification enzymes are cultured with soil. In addition, a column study will be carried out to quantify impact of humification on hormone transport in soils