Joe Bisesi, PhD
Assistant Professor
Department of Environmental and Global Health,
Center for Environmental and Human Toxicology
Faculty Profile Page
Dr. Joe Bisesi’s training is grounded in aquatic toxicology with a focus on studying the effects of waterborne toxicants in humans and aquatic organisms. Additional training in the examination of molecular mechanisms of toxicants in mammalian and fish models allows Dr. Bisesi to work across human health toxicology and ecotoxicology to address complex public and environmental health issues related to environmental contaminants. Dr. Bisesi’s current research program spans both freshwater and marine systems and is focused on elucidating the effects and toxic mechanisms of numerous emerging contaminates, including nanomaterials, plasticizers, and pharmaceuticals as well as legacy contaminants of concern including pesticides and heavy metals. Much of his research is focused on the gastrointestinal system, which is an understudied target of chemical contaminants. His research has been published in numerous high impact environmental journals including Environmental Science and Technology, Environmental Toxicology and Chemistry, Aquatic Toxicology, and Environmental Science: Nano. His research has been funded by the National Science Foundation, the National Institutes of Health, Florida Sea Grant, and the Electric Power Research Institute. In addition to his research program, over the past year, Dr. Bisesi has served as one of the lead investigators for the SARS-CoV-2 wastewater surveillance program on the UF campus as well as the cities of Gainesville and Cedar Key.
Example Research Projects:
Understanding the behavior of particle bound contaminants in the gastrointestinal system of fish
Particulate contaminants including nanomaterials and microplastics have emerged as a significant threat to both freshwater and marine ecosystems. While these contaminants may exert toxicity on their own, their small size, large surface area, and lipophilic chemistry is ideal for adsorption of organic chemical contaminants. Particulate bound chemical contaminants are not typically considered to be bioavailable, however, Dr. Bisesi’s NSF funded research suggests that these contaminants can desorb in the gastrointestinal system resulting in uptake and toxicity. Using single-walled carbon nanotubes as a model particle, his research has shown that moderately hydrophobic pharmaceuticals including ethinyl estradiol and venlafaxine readily adsorb to these particles. When particle and adsorbed chemicals are fed to fish in the diet, the particles do not cross the gastrointestinal epithelium, however, the chemicals rapidly desorb from the particles causing bioaccumulation and associated toxicity. Additional research from his group indicates that interaction with epithelial and luminal lipids are the most likely driver of this behavior. These findings have far reaching implications for freshwater and marine ecosystems as risk assessments for these particles may need to consider both particulate toxicity as well as trojan horse style delivery of adsorbed contaminants to aquatic organisms.
Integration of episodic exposure duration and frequency into the biotic ligand model for heavy metals
The biotic ligand model (BLM) has emerged as an important tool for predicting bioavailability and toxicity of heavy metals. BLMs have been developed for a suite of heavy metals in both freshwater and marine systems where they can be utilized to develop aquatic life criteria based on detailed site specific water quality measurements. These models have been adopted by the US EPA and state agencies around the country, however, the models do not currently include episodic exposure duration and frequency as variables. These variables are important as both point and non-point discharges of heavy metals are episodic in nature. Dr. Bisesi has been working with the Electric Power Research Institute and Windward Environmental to provide exposure data aimed at developing a biotic ligand episodic exposure model (BLEEM) for copper and zinc that will integrate these two variables. Results so far indicate that episodic exposures are likely much less toxic when compared to continuous exposures used for the development of most heavy metal aquatic life criteria. Additionally, short breaks between multiple exposure pulses drastically reduces toxicity when compared to continuous exposures. Once complete, these models will allow for more accurate prediction of site specific risk to aquatic life from episodic heavy metal exposure.