As part of its ECO21-ARC research project, LRI has agreed to sponsor a Pellston workshop on the Ecotoxicological Risk Assessment of Ionizable Organic Chemicals. The workshop will take place at the Environment Canada Offices, Vancouver, BC, Canada on 5, 6 and 7 November 2014.
Because assessment of ionogenic substances is occurring globally right now, the goal of the workshop will be to produce practical “state of the science” guidance to help the assessment of fate (e.g., bioavailability, bioaccumulation), exposure (e.g., WWTP removal) and toxicity (e.g., reactivity, testing regimes) of ionogenic substances.
The workshop will address the following key questions:
• What is the most appropriate testing strategy for acute and chronic ecotoxicity tests of ionisable chemicals?
• What do we know about the relative importance that changes in environmental or organ (e.g., gut vs. blood) pH may have on the bioavailability of the chemical substance with respect to its pKa? Should ecotoxicity tests be performed at a range of different pH values?
• How do we improve our understanding of bioavailability and sorption processes, particularly for cationic materials that have the potential to sorb to a wide range of negatively charged surfaces in the environment?
• Should we consider the role of counterions (i.e., salts) in influencing the environmental fate and behaviour of ionisable organics?
• How do we incorporate knowledge of bound-residues within an environmental exposure assessment for ionisable organics and how do bound residues influence our ability to adequately assess bioavailability?
• What is the role of bioaccumulation when assessing ionogenic substances? Do B criteria matter? Why?
• What are the important mechanistic processes governing the distribution of ionogenic compounds within organisms (e.g., PFOS, weak acids/bases vs. strong acids/bases)? Why is this important?
• Should we be more concerned with receptor mediated interactions (e.g., estrogen receptor binding) vs. legacy POPs? (e.g., BPA, TBBPA)
• What structural features or properties should be avoided when designing new ionogenic chemicals?
This Pellston workshop is co-sponsored by the Health and Environmental Sciences Institute (HESI), the Society of Environmental Toxicology and Chemistry (SETAC), governments (such as Environment Canada) and industry.