Review of EPA's Updated Problem Formulation and Protocol for the Inorganic Arsenic IRIS Assessment

The EPA has been working on its IRIS assessment of inorganic arsenic (iAs) for many years, and recently released its plans for completing it in the Updated Problem Formulation and Protocol for the Inorganic Arsenic IRIS Assessment. Much of the update was made in response to recommendations in a 2013 report made by the National Academies of Sciences, Engineering, and Medicine. The National Academies recently convened another evaluation of whether the various elements of the IRIS iAs assessment plan are appropriate to synthesize the scientific evidence and quantitate estimates of iAs toxicity. Review of EPA's IRIS Assessment Plan for Inorganic Arsenic explores the EPA's approach to prioritizing health outcomes, EPA's systematic review methods, EPA's consideration of potential health effects from early life exposures, mode-of-action information to inform dose-response analyses, and various approaches to investigate dose-response relationships.