What are considered endocrine disruptors in waterways, affecting reproduction and development?

• A. Nutrients
• B. Pathogens
• C. Endocrine disruptors from pharmaceuticals and waste that affect reproduction and development
• D. Salts

Answer: (C)

Endocrine disruptors are chemicals that interfere with hormonal signaling in organisms. In waterways, these often come from pharmaceuticals and human waste that enter streams and rivers. They can mimic natural hormones or block hormone receptors, alter hormone production or metabolism, and disrupt how reproductive systems develop and function. That’s why the best answer points to endocrine-disrupting compounds from pharmaceuticals and waste that affect reproduction and development. Other options—nutrients, pathogens, or salts—cause different environmental issues (nutrient-driven eutrophication, disease, or osmotic/ionic stress) and do not primarily operate by altering hormonal signaling in the body.