Feminization in males is primarily caused by exposure to endocrine disruptors, which are chemicals that can interfere with the endocrine system. These substances can mimic, block, or alter hormone levels, leading to changes in reproductive and developmental processes. Common sources of endocrine disruptors include pesticides, industrial chemicals, and pharmaceuticals. Notable examples include Bisphenol A (BPA) and phthalates, which are found in plastics and personal care products, respectively.