(656d) Life Cycle Environmental Implications of Silver Nanoparticle Applications

The benefits of nanomaterials in environmental and medical applications must be judged alongside potential negative impacts from their production or uncontrolled release.  In a series of studies, we have examined the life cycle of silver nanoparticles (AgNPs) in consumer products.  These studies include comparison of chemical and physical synthesis routes, determination of appropriate functional unit based on antimicrobial activity, leaching during use, and potential ecological impacts of releases.  Modeling and experimental work has been assembled into nanomaterial life cycle assessments, used for risk analysis and product design.  The relative contribution of AgNPs to life cycle benefits or impacts of consumer products depends on many factors, including method of particle incorporation, silver concentration, material composition, and the role of AgNPs in the function of the product, and was found to range from 10-90% across 15 product types and multiple impact categories. For products used for antimicrobial purposes, results were rescaled based on efficacy using empirical zone of inhibition tests. These analyses can be used to guide AgNP and nano-enabled product design as well as evaluate loading levels of AgNPs in products that indicate either direct or indirect risk to the environment and public health.