Green nephrology: water and waste - one year in a hemodialysis unit in Northeastern Brazil and reassessment of dialyzer reprocessing from an environmental perspective.

INTRODUCTION: Hemodialysis is one of the most water-intensive and waste-generating therapies in health care, yet its environmental impact remains poorly documented in low- and middle-income countries. This study aimed to estimate water consumption and solid waste generation in a hemodialysis unit in northeastern Brazil that reprocesses dialyzers, comparing the observed scenario with an estimated counterfactual single-use scenario. METHODS: This was a single-center, retrospective observational study. Aggregate institutional data on water consumption, supply procurement, and waste mass were analyzed over a 12-month period. An estimated counterfactual single-use scenario was constructed using mathematical projections, assuming one new dialyzer per session. Carbon dioxide equivalent (CO2-eq) emissions were estimated using an emission factor for the incineration of clinical waste. RESULTS: A total of 34,759 hemodialysis sessions were performed, with a mean of 223 patients/month. Total water consumption was 14.9 million liters, corresponding to 429 L/session (2.3% attributed to reprocessing). Solid waste generation was 30.9 t (0.89 kg/session), consisting of 21.6% contaminated waste, 51.5% solution containers/bottles, and 26.8% cardboard. Of all plastic waste, 70.4% was recycled and 29.6% was incinerated. In the counterfactual single-use scenario, waste generation was estimated to increase by 78.7%, incinerated plastics by 312%, and associated emissions by an additional 37.5 t of CO2-eq. CONCLUSION: The comparison of the two scenarios suggests that dialyzer reprocessing had a marginal effect on water consumption and reduced waste generation and associated emissions. These comparisons should be interpreted as environmental estimates; they do not allow causal inferences or universal recommendations.