Nanoparticles (NPs), particles defined by their size in a single dimension (1-100 nm), are being increasingly incorporated into commercial and industrial products due to their high surface area to volume ratio that gives them unique properties, such as optical tunability and higher reactivity than their bulk counterparts. NPs can be...
Emerging data showing the presence of atmospheric microplastics (MPs) has recently raised awareness surrounding the potential of human nanoplastics (NPs) exposure. Due to factors such as weathering, UV exposure, and other biodegradation processes, plastic pollution in the environment breaks down over time into micro (<5 micrometers) and nanoscale (<1000nm) particles....
Nanotechnologies continue to permeate a multitude of industries, with diverse applications ranging from pesticides to fuel additives. The unusual behavior of nanomaterials that drives their innovation also complicates the job of toxicologists tasked with assessing their potential environmental and public health impacts. This dissertation investigates the underlying reasons for uncertainty...
The low risk and sustainable implementation of nanotechnology requires understanding how nanomaterial physicochemical properties influence their toxicity. Major drivers of toxicity need to be avoided while maximizing product efficacy so nanomaterials can be produced to best serve their applications and be of low risk when intentionally or unintentionally released into...
Within the past two decades, the rise of nanotechnology has provided various technological and industrial sectors with avenues for significant growth and improvements to existing practices. With the inherent qualities which make materials on the nanoscale unique in behavior and function, there are limitless applications of nanotechnology. One of the...
Many studies addressing the toxicity of silver nanomaterials have found that smaller sized silver nanoparticles are usually more toxic to organisms and in cell culture than particles of larger sizes yet it is not entirely clear why. We investigated the size dependent toxicity of silver nanoparticles by measuring the response...
The numerous different types of nanomaterials and paucity of reliable in vivo information on toxicity has resulted in enduring uncertainties associated with health and safety risks, thereby slowing progress in nanotherapeutic assessment and development. This dissertation explores how the embryonic zebrafish model can be applied to prioritize commonly used nanomaterial...
Chlorpyrifos (CPF) is a widely used broad-spectrum organophosphate insecticide. Following exposures, CPF and its more toxic oxon metabolite (CPFO) elicit neurotoxic effects by inhibiting the activity of the acetylcholinesterase enzyme (AChE), resulting in altered fitness and death at high doses. Following exposure, organisms bioactivate CPF to CPFO through the Cytochrome...
Incorporation of nanoparticles (NPs) into consumer products is on the rise and human exposure to NPs is unavoidable. Currently, there is insufficient data to assess the safety of nanoparticles. I conducted a series of five studies using the zebrafish model to determine which NP components (i.e., core material or surface...
Assessing the risk from exposure to a chemical mixture in the environment can seem prohibitively challenging. Most components of the mixture are not readily identifiable, chemicals may interact to cause other-than-additive toxicity, and the number of potential combinations of environmental contaminants is enormous. These challenges can make it seem impossible...