Human health characterization factors of nano-TiO<Subscript>2</Subscript> for indoor and outdoor environments

Purpose

The increasing use of engineered nanomaterials (ENMs) in industrial applications and consumer products is leading to an inevitable release of these materials into the environment. This makes it necessary to assess the potential risks that these new materials pose to human health and the environment. Life cycle assessment (LCA) methodology has been recognized as a key tool for assessing the environmental performance of nanoproducts. Until now, the impacts of ENMs could not be included in LCA studies due to a lack of characterization factors (CFs). This paper provides a methodological framework for identifying human health CFs for ENMs.

Methods

The USEtox? model was used to identify CFs for assessing the potential carcinogenic and non-carcinogenic effects on human health caused by ENM emissions in both indoor (occupational settings) and outdoor environments. Nano-titanium dioxide (nano-TiO₂) was selected for defining the CFs in this study, as it is one of the most commonly used ENMs. For the carcinogenic effect assessment, a conservative approach was adopted; indeed, a critical dose estimate for pulmonary inflammation was assumed.

Results and discussion

We propose CFs for nano-TiO₂ from 5.5E?09 to 1.43E?02 cases/kg_emitted for both indoor and outdoor environments and for carcinogenic and non-carcinogenic effects.

Conclusions

These human health CFs for nano-TiO₂ are an important step toward the comprehensive application of LCA methodology in the field of nanomaterial technology.

     

How can LCA include prospective elements to assess emerging technologies and system transitions? The 76th LCA Discussion Forum on Life Cycle Assessment, 19 November 2020

This paper summarizes the 76th LCA Discussion Forum end its main findings. Main issues when addressing emerging technologies identified were: the lack of primary data, the need for (shared) future background scenarios and (guidlines for) a common methodology. The following recommendations have been derived by the organizers: 1) Specific foreground inventories are always tailor-made, but consistency can be improved through lists of mandatory considerations. 2) Continue sharing (future) technology data and proxy processes, that can be readily replicated to new studies and assist in developing inventories. 3) Streamline and unify the process of including scenarios for background systems. New approaches may provide first important solutions to efficiently include consistent future scenarios in prospective LCA.