Presence of ammonia/ammonium and anoxic conditions (lack of oxygen) is known to reduce spore germination, not increase it.
Pollutants, such as heavy metals (Hg, Cu, Cr, Co, Zn, Pb, etc.), pesticides or insecticides (carbofuran, 2,4-D, dithane, phorate, bavistin, parathion, etc.), sewage...