Water scarcity compromises safe hygiene practices. That leads to the transmission of diseases like infectious diarrhea and hepatitis. Current wastewater practices have also contaminated ecosystems worldwide with 6.2 million tons of nitrogenous products.

Repurposing urine has great potential to solve these problems. It is an ideal fertilizer because it is rich in nutrients like potassium and nitrogen. In addition, studying urine can help detect or diagnose about 600 physiological or pathological conditions, including diabetes and cancer. So, a smart toilet could also separate urine for medical analysis, which has great potential for at-home, non-invasive health monitoring.

We reviewed emerging toilet and sewage technologies that repurpose wastewater. We found that urine-diverting dry toilets— which can automatically separate urine from other waste products—would both conserve water and prevent ecosystem contamination. This toilet conserves water by using little to none. These toilets can also turn the urine into a powdered, nutrient-rich product equivalent to commercial fertilizer.

These reimagined toilets are worthy of consideration. They can help address several public health and environmental challenges of the 21st century. They can be seamlessly integrated into daily life and help people collect physiological data in a fully automated fashion in the comfort of their homes. That could allow screening, diagnosis, and continuous health monitoring for individuals or wider communities.