David Patch

Ph.D. Candidate

Chemistry & Chemical Engineering

The Royal Military College of Canada

Affiliation

2019 - Present 

Supervisor(s): Kela Weber

Research Project:  Release of Silver Nanoparticles from Commercial Products into the Water Cycle

Emerging contaminants (EC) are compounds found in the environment that are growing as a source of possible concern due to increases in concentration, unknown impact to human/environmental health, and complexities surrounding their transport potential. As commercial manufacturers incorporate new materials into their products there exists the potential for the release of EC through mechanisms of use and weathering of the products. Current methods often analyze bulk concentrations of a species present in the commercial product with little focus on the mechanisms of release common in active use scenarios. Understanding the mechanism of release is important because these mechanisms are often responsible for transformations to the contaminant, altering its transport and toxicity potential. 

The emerging EC of concern for this project are silver nanoparticles. Ionic silver has been studied in the past for their release directly into the environment (from photographic waste) but the unique properties of nanoparticles and their incorporation into commercial products represents an area of concern due to potential for direct exposure to humans, release into the water cycle, and potential for transformation into other species. Silver nanoparticles have been found in common commercial products including clothing, food packaging, medical devices, sprays, and manufacturing materials and is often incorporated to inhibit bacterial growth. There currently exists no methodology to release and characterize silver nanomaterials being released from commercial products during active use scenarios. This research is to develop weathering methods capable of simulating physical and chemical conditions that silver-coated clothing undergo during their active use, which in turn will release silver nanomaterials characteristically similar to those released by human use. These released materials will then be examined the toxicity of these particles in wetland mesocosm systems.