In the 1940s, penicillin was so hard to get, that scientists studied how to recycle it from patients' pee. It demonstrates how the human body does a poor job of metabolizing the antibiotics and other pharmaceuticals we ingest. It depends on the drug, but roughly speaking, 25-75% of the antibiotics we consume are excreted. Mostly as urine, due to the drugs' solubility. The average rate is 70%. So considering the thousands of tons of antibiotics we all consume each year, it makes me wonder. What are all those antibiotics in our wastewater doing? And what can we do about it?