Effluents containing pharmaceuticals and hormones from CAFOs are of concern because they are directly applied to the soil without any pre-treatment. To evaluate the potential affect of these compounds, an understanding of soil ecology is required. Soil ecology is a daunting topic as there is so much soil mass and diversity in the world. However, some parameters are consistent for the study of the factors of soil ecology, like nematode numbers and bacterial/fungal biomass. The biomass can by characterized by using arrays of distinct substrates used or amounts of specific chemicals produced, e.g. ergosterol is produced primarily by fungi.