Fate and effects of metallic nanoparticles in wetland systems

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Nanotechnology offers exciting scientific advancements. However, with these advancements there is also concern over the effects these same engineered nanoparticles (ENPs) can have on the environment. The risk of ENPs on the environment is largely unknown due to a lack of information on the properties of ENPs released from commercial products, a lack of information on the ecosystem level effects of ENPs, and a general knowledge gap in the fate and transformation of ENPs once they enter ecosystems. Previous research has largely used ENPs generated in a lab environment or purchased from suppliers, which do not represent the properties of ENPs released from commercial products. As such limited knowledge currently exists regarding the toxicological effects of ENPs released to the environment. Wetlands cover 14% of Canada and provide ecosystem services including large scale water purification for Canadian drinking water supplies, nutrient cycling, buffering of hydrological events (e.g. potential flooding). They also provide food and habitat for wildlife, products (e.g. lumber), and recreational areas. Wetlands are expected to receive ENPs through either water treatment plant effluents released into lakes or streams (wetlands are commonly found as transition zones between aquatic and terrestrial zones), or through runoff and up-flow aquifer transport originating from surface biosolids spreading. Using recently developed methods and knowledge regarding ENP releases from commercial products, a broad spectrum ENP characterization approach, and world-class treatment wetland and microbiological characterization facilities, this project will fill current knowledge gaps with respect to metallic nanoparticles in the environment. The overall goal is to gain a new and better understanding of the fate and effects of silver (Ag) and titanium dioxide (TiO2) ENPs in Canadian wetland environments. This overall goal will be achieved over five years through three sub-objectives, A) Develop methods of wearing commercial products to release representative Ag and TiO2 ENPs, B) Determine the effects of Ag and TiO2 ENPs on Canadian wetland sediments and plants, C) Determine the fate and effects of Ag and TiO2 ENPs in wetland mesocosms. Three MASc, two PhD, one PDF, and 15-20 undergraduate students will be trained through this program. In addition to specialised ENP training, students will also gain access to field sites, be given opportunities for field skill training, and interact with Canadian environmental professionals. Information gained from this research program will give direct insight into the effect of the selected ENPs on a fundamentally important Canadian ecosystem, giving policy makers an additional body of evidence assisting in developing guidelines and standards related to their use, release, and maximum allowable concentrations.