The importance of exposure dose in communicating the ecotoxicology of engineered nanomaterials
Thomas A. Duster
Future policy decisions related to the control of engineered nanomaterials during consumer use and disposal will be predicated in part on their toxicities to natural environmental systems. Using titanium dioxide nanoparticles (nTiO2) as a model nanomaterial, this chapter critically evaluates the capacity of existing ecotoxicology literature to communicate the potential for harm to environmental systems by searching for confluence between: (a) nTiO2 concentrations expected in surface waters; (b) nTiO2 concentrations that result in specific toxicological responses to aquatic organisms; and (c) the availability of reliable methods/instrumentation that can quantitatively measure nTiO2 concentrations in real aqueous solutions. This examination found that direct measurements of nTiO2 loading in aquatic ecosystems are limited by a dearth of analytical techniques that can simultaneously measure nTiO2 size and concentration. Model predictions suggest that nTiO2 concentrations in surface waters will likely be significantly less than 100 μg/L, yet relatively few ecotoxicology studies use similarly low exposure doses. In fact, a survey of 30 well-cited nTiO2 ecotoxicology papers found that only 22 percent of the associated experimental treatments used an environmentally- relevant concentration of 100 μg/L or lower, despite reliable indications that these doses often result in toxic responses. The analysis presented in this chapter suggests that significant questions remain regarding the concentrations and toxicities of engineered nanomaterials in real aquatic systems, which will need to be addressed prior to the development of scientifically-sound policies and regulations.
Science and the Law: How the Communication of Science Affects Policy Development in the Environment, Food, Health, and Transport Sectors
The importance of exposure dose in communicating the ecotoxicology of engineered nanomaterials, Science and the Law: How the Communication of Science Affects Policy Development in the Environment, Food, Health, and Transport Sectors, American Chemical Society, Washington, DC, DC, [online], https://doi.org/10.1021/bk-2015-1207.ch008
(Accessed June 20, 2021)