This work package is devoted to the study of the transformation and/or release of ENM along their life cycle (production, manufacturing, use and disposal) when used in existing applications or industrial processes, and the assessment of environmental and health impacts of these releases. Efforts will concentrate firstly on identifying the main industrial applications, using information provided by relevant companies.
The criteria for the selections will include: the current existence of final products incorporating the ENMs of relevance to NANOSOLUTIONS or, otherwise, their production for close to market applications, and the volume of production as well. For each ENM and application selected, the life cycle stages that are most likely to result in the transformation of the ENMs and/ or to result in the release of ENMs from cradle to grave will be defined. Those will determine the selection of realistic simulation processes to be undertaken, using a range of nanotechnology-enabled products of commercial relevance.
Experimental simulations will allow evaluation of the transformation, quantify the release and to collect the transformed or released ENM for hazard testing in other work packages, to compare with the initial nanomaterials.
Outcomes of the workpackage
INKOA performed a selection of representative applications incorporating each ENM type to be studied in the execution of NANOSOLUTIONS, according to the information provided by industrial partners in the consortium. Additionally, a description of the life cycle stages of the ENM depending on the application or consumer product was carried out; special relevance has been given to the life cycle stages beyond the manufacturing stage.
Thereafter, the life cycle stages that are most likely to result in the transformation of the ENM and/or to result in the release of ENM were identified.Priority was given to the applications in conditions of normal use and tests were conducted under Task 4.2 and Task 4.3 on this basis.
The life cycle stages specifically described for each application, and estimations of the most relevant life cycle stages in terms of nano-release, were assessed by INKOA in collaboration with other partners. Finally, laboratory scaled release simulations were established by LEITAT on the basis of the former information.
According to the outcomes of the previous task, and the information provided by the industrial partners, ENM were selected. The NM-enabled products studied were grouped into four main application sectors: the textile industry (TiO2, CuO, Ag NPs and MWCNT), the ink industry (CdTe quantum dots), nanomedicine (Au nanoparticles), and the automotive-oil additives industry (nanodiamonds). Experimental simulations, characterization of the materials before and after simulations, as well as the material released study were explored.Details can be found in deliverables D4.2 and D4.3. The simulations carried out were: washing for nano-enabled sportswear fabrics (TiO2, CuO, Ag NPs), abrasion for polymeric nanocoatings applied on a car arm rest (MWCNT), printing for ink (CdTe QDs), oil recirculation for automotive-oil (nanodiamonds) and physiological fluids exposure for gold NPs. One real application for all nanomaterials was evaluated to enable the understanding of the possible transformations of these nanomaterials during common use conditions. An important goal was also to characterize possible ENM release from such products.
Different approaches were followed according to the nature of the experiment. For instance, waters were collected from fabrics washing experiments, CdTe emitted to air were collected during printing, or MWCNT embedded in polyurethane were collected in filters after being measured by particle counters. In other cases, such as the diesel oil containing nanodiamonds or gold dispersions, experimental work was focused on characterizing the transformations of ENM inside the products by means of different analytical techniques (e.g., ICP-MS, Raman Spectroscopy or TEM-EDX). According to the results obtained, the following general conclusions can be drawn (for further details see deliverable D4.3).
- Nanomaterials in the textiles (Ag, CuO and TiO2) are weakly bound to the fabrics and hence easily released to the waste water treatment system.
- For antistatic fabrics containing MWCNT, abrasion experiment has revealed that low ENM releases from the matrix into air or soil occurred.
- In oils, nanodiamonds showed some chemical changes, especially metals transference from the engine to the ENM.
- In inks, CdTe particles were aerosolized during printing and emitted to air being especially of concern because Cd2+ is highly toxic.
- Au nanoparticles for biomedical applications may exhibit instability in both gastric and urine simulated fluids because of the formation of large aggregates that sediment over time.
In order to assess the release and transformation of the ink containing CdTe QDs, ENM in all the stages of its life cycle was explored. Abrasion of printed papers (rubbing) showed high cadmium transference from paper to the cotton abrader material. End-of life was simulated with leaching experiments indicating QDs were released. From the results it was concluded that tellurium is released much more readily than cadmium.
Additionally, the nanoparticle emissions during printing process in controlled conditions were characterized, and the assessment of their toxicological effect was carried out in routine cultures of pulmonary cell cultures and by using air-liquid interface with the same cells. These emissions were not large enough to elicit a toxicological cellular response.
The USEtox model was applied to derive human toxicity and freshwater effect factors for selected NANOSOLUTIONS ENM, namely MWCNT, TiO2 and Ag. Work was carried out by TNO (on the human impact perspective) and LEITAT (for the freshwater ecotoxicity).
Subsequently, complete characterization factors (CFs) (effect factor, fate and exposure factor) for CdTe quantum dots (QDs) both for human and freshwater ecotoxicity have been derived.Finally, these values have been integrated into a Life Cycle Assessment (LCA) on the basis of the internationally recognized ISO framework for LCA (ISO 14040:2006) for PEG-CdTe in printing ink case study.The present action goes far beyond the state of the art in LCA studies for ENM in which these aspects generally remain uncovered.