Risk Ranking of ENPs of Human Health Concern

Nanotechnology has numerous applications with increasing usage in industry, the corresponding risks need to be assessed, particularly in relation to concern for consumer health while also recognising nanoparticles as a novel class of pollutants. However, due to current knowledge gaps regarding toxicity, and the wide ranging market applications of engineered nanoparticles (ENPs), traditional risk assessment, based on material flow of pollutants, may not be feasible. In this context, a proactive specialised risk ranking for ENPs, which matches current data availability, was developed. In accordance with the standard risk assessment methodology, market information, exposure scenarios, and toxicity studies were introduced to develop a risk scoring system. Exposure and hazard potential (dermal, inhalation and oral routes) were characterized for the most used ENPs within Europe. A risk prioritisation was provided by this model. Nano-TiO2 was ranked as the most critical ENP, which is due to the large quantities used and the many exposure pathways through the consumer market. The second highest ranked ENP was found to be AgNP, which is mainly due to the many environmental sinks, especially through water sources. Key information gaps were also highlighted for upgrading the quantification level of the ENP risk assessment. This model can pave the way for the full quantification of ENP risk potential, and previse the potential ENP risks throughout their life cycle and corresponding consequences for human health.