Description:

Metal Bioavailability and Toxicity to Aquatic Organisms

Abstract:

In the aquatic environment, heavy metals interact with inorganic and organic components and form different metal species. Among the metal species, free metal has been believed to be the most bioavailable species and cause toxic effects to living organisms. This seminar presents the results of over 15 years of research on the influence of water quality on metal bioavailability and toxicity to standard and nonstandard aquatic organisms. The seminar will cover research with both individual and mixture of multiple metals. Results of the research have been published and used for setting relevantly environmental quality criteria for aquatic life in the US and Europe.

Biography:

Dr. Tham Hoang is an Associate Professor at the Institute of Environmental Sustainability of Loyola University Chicago. He received his Ph.D in Environmental Toxicology with a Minor in Environmental Statistics from Clemson University in 2006 and joined Loyola University Chicago in 2011. Since graduation, he has conducted research in the field of environmental toxicology. His research has a strong focus on the influence of chemical and physical characteristics of water and sediment on the bioavailability and toxicity of metals in the aquatic environment. He used both traditional exposure method, such as constant exposure and fluctuating exposure method, which is more environmental relevant for his research. Results of his research are to 1) determine the bioavailability, bioconcentration and bioaccumulation of metal and organic contaminants, including microplastics, 2) evaluate potential toxicity of individual and mixture chemicals in water, sediment, soil, and diets, 3) understand mechanisms of toxicity, 4) evaluate toxicity of effluent wastewaters and determine causative agent(s) through toxicity identification evaluations, 5) prepare ecological hazard and risk assessments for aquatic and terrestrial environments, and 6) provide guidance to optimize efficiency of site cleanups and assist in development of environmental quality guidelines.

In addition to conducting research in the US, Dr. Hoang is also interested in bringing his research field to Vietnam and other Southeast Asian countries. He has collaborated with the Society of Environmental Toxicology and Chemistry to initiate and organize a series of International Conference on Environmental Pollution, Restoration, and Management and Training Workshops on Ecological Risk Assessment in Vietnam since 2010. Thus far, three conferences and 4 workshops have been organized with an attendance of scientists from over 30 countries around the world.  The conferences and workshops have helped enhancing collaborations on research and education between scientists in developed and developing countries, typically Southeast Asian countries. A collaborative project with colleagues in Vietnam, Thailand, Cambodia, and China on Cu bioavailability and toxicity to aquatic organisms in support of developing Cu water quality criteria for the Mekong River ecosystem was also conducted after the conferences. Through the workshops, local environmental regulators were educated with knowledge and risk assessment methods that can be used for management.