2013 • Engineering and Technology
Life Cycle Assessment of Silver Nano-Particles in Medical Bandages
Lead Presenter: Leila Pourzahedi
From clothing to cleaning to medical devices, silver nano-particles (SNPs) are widely used today, especially due to their antibacterial/antifungal properties. Various studies have been conducted on the toxicity of these particles to various aquatic organisms due to releases from their use and disposal phases, but very few have examined life cycle environmental impacts by further considering resource-intensive SNP production processes. æOne of the fastest growing end-uses of SNPs is medical supplies and devices, and our study looks at the life cycle impacts of SNPs incorporated into medical bandages, taking the existing gap in SNP manufacturing into consideration alongside other phases of their life cycle. æProduction data from various literature and SNP and medical equipment manufacturing companies were collected and used as the basis for a life cycle inventory, while experimental leaching tests provided empirical corroboration of stated properties. The environmental burden of different production methods and fate, transport, and release scenarios were simulated and compared. æLife cycle impact assessment was conducted using EPAÍs TRACI method with the USEtox model for consideration of toxicity categories. æUSEtox was amended to include physic-chemical processes typical of SNPs, including settling, aggregation, and dissociation into silver ions. æPreliminary results suggest that production-phase toxicity is significantly greater than that of any of the fate, transport, and release scenarios considered. Our results suggest that priority should be put on improving manufacturing and syntheses techniques of SNPs by moving towards green chemistry and alternate synthesis routes in order to mitigate their environmental impacts.