UC Santa Barbara

Recent interest in the environmental fate and effects of manufactured CeO2 nanomaterials (nanoceria) hasstemmed from its expanded use for a variety of applications including fuel additives, catalytic converters,chemical and mechanical planarization media and other uses. This has led to a number of publications onthe toxicological effects of nanoceria in ecological receptor species, but only limited information isavailable on possible environmental releases, concentrations in environmental media, or environmentaltransformations. Increasing material flows of nanoceria in many applications is likely to result in increasingreleases to air, water and soils however; insufficient information was available to estimate aquaticexposures that would result in acute or chronic toxicity. The purpose of this review is to identify whichareas are lacking in data to perform either regional or site specific ecological risk assessments. Whileestimates can be made for releases from use as a diesel fuel additive, and predicted toxicity is low in mostterrestrial species tested to date, estimates for releases from other uses are difficult at this stage. Werecommend that future studies focus on environmentally realistic exposures that take into accountpotential environmental transformations of the nanoceria surface as well as chronic toxicity studies inbenthic aquatic organisms, soil invertebrates and microorganisms.