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Key scientific issues for assessing the health effects of vanadium ingestion
Citation:
Yost, E., K. Newhouse, Suryanarayana Vulimiri, E. Radke-Farabaugh, B. Glenn, AND D. Farrar. Key scientific issues for assessing the health effects of vanadium ingestion. 12th International Vanadium Symposium, NA, November 04 - 06, 2021.
Impact/Purpose:
This presentation describes the approach that will be taken towards addressing vanadium chemistry in the IRIS assessment of oral exposure to vanadium and compounds. The audience will be attendees at the 12th International Vanadium Symposium, i.e., vanadium health scientists, engineers, and industry representatives. The conference will be held via webinar.
Description:
Vanadium is an element with complex chemistry, which must be considered when interpreting health effects data for human health risk assessment. We will present a survey of the available human and animal health effects studies that evaluate oral exposure to vanadium and compounds and discuss key scientific issues for human health risk assessment, based on the U.S. Environmental Protection Agency’s (EPA) Integrated Risk Information System (IRIS) systematic review protocol for the assessment of oral exposure to vanadium and compounds (U.S. EPA, 2021). One key scientific issue is that differential absorption and toxicity have been observed across inorganic vanadium compounds and oxidation states, with sodium metavanadate (V+5) observed to have greater gastrointestinal absorption and increased toxicity relative to vanadyl sulfate (V+4) in animal models. A second key scientific issue is that vanadium compounds in solution can convert readily between oxidation states and will form different spectra of species as a function of factors including pH, concentration, and redox potential. The interconversion of vanadium species and oxidation states in solution has the potential to impact bioavailability and toxicity. Confidence in the interpretation of health effects data can therefore be increased if study authors are able to analytically confirm the oxidation state or species of vanadium in an exposure scenario, and if factors such as pH of dosing solutions are monitored and reported.