Inventory of country-specific emissions of engineered nanomaterials throughout the life cycle

Engineered nanomaterials (ENMs) are being increasingly produced for various applications. In order to evaluate potential environmental impacts, knowledge on their environmental releases is needed. In this study, we present a country-specific assessment of the flows to the environment from production to end-of-life of nano-Ag, -TiO2 and -ZnO within Europe. This paper includes a revision of the different applications in which the ENMs are used and their shares in Europe, as well as the distributions of ENM production, manufacturing and consumption over European countries using a surrogate-variable approach. Material flow analysis was used to quantify the probability distributions of ENM releases from each lifecycle stage to air, water and soil. Results show that the main applications of nano-TiO2 and nano-ZnO are in cosmetics and personal care products, while nano-Ag is mainly used for electronic printing. While the production of these ENMs takes place in a limited number of countries, manufacturing and consumption are more homogeneously spread over Europe. In general, sludge-treated soil is the environmental compartment receiving the highest releases, while recycling is a technical compartment in the waste management system receiving significant ENM shares, especially for nano-Ag. Due to different waste management systems and sizes of countries, releases to surface water and soils normalised by the areas of these compartments vary by several orders of magnitude between countries, showing the relevance of a country-specific model. The results of this study can be used for the country-specific assessment of environmental fate and risks of ENMs and ENM-containing products.