Human Health and Ecotoxicity Considerations in Metallic Alloy Design

The increasingly prevalent use of metallic alloys in consumer products, medical devices, and sophisticated industrial applications warrants consideration of their potential adverse impacts on both human health and ecosystems, early in product and process development. We review recent advances in understanding metallic toxicity and the criteria used by national and international databases to categorize metals in terms of potential hazards and precautional regulatory responses. We note that the existing databases are populated with scientific information on individual metallic elements, and these databases contain gaps and occasional incompatible data, all of which may not apply neatly to the attributes of metallic elements in alloys. We present three case studies, two on conventional metallic alloys (Al 3003 vs Al 7075, Monel vs Inconel 718), and one on high entropy alloys (Cantor vs a recent refractory composition) to explore the potential contributions of individual elements to alloy composition and predictable characteristics associated with human health effects and ecotoxicity. Finally, we note that in addition to direct toxicity characteristics, the production of metals and metallic alloys can be energy intensive, and the process may generate additional toxic compounds worth considering in their overall environmental footprint and potential contributions to the burden of disease in human populations. New tools including machine learning and generative artificial intelligence may support innovative approaches for developing more precise appraisal of human health and ecotoxicity considerations in metallic alloy design.