A model for screening the fate and behaviour of the engineered nanoparticles in aquatic systems using semi-quantitative analysis and rule-based system

Concerns over the possible adverse effects of engineered nanoparticles (ENPs) on aquatic organisms have grown due to their continuous emission into aquatic systems. Consequently, to safeguard these aquatic life forms and support the sustainable use of ENPs, the characterisation of their exposure is necessary. Currently, despite the great amount of work reported to elucidate the exposure and risks of ENPs, cost-effective and easy-to-use exposure characterisation models are lacking and scarce. This study describes the use of semi-quantitative analysis (SQA) integrated with a rule-based system to evaluate ENP exposure in aquatic systems. The performance of the model was illustrated using case studies of nZnO, nTiO₂, and nAg and theoretical examples that simulate natural systems. The results demonstrate that our proposed model can be highly valuable as an alternative approach for the preliminary screening of the exposure and possible environmental impact of ENPs in aquatic systems. The SQA application is relatively cost-effective and easy to use, since no software or mathematical computations are required. In addition, non-experts can easily understand the hierarchical nature, Boolean logic, and visual representations of simple rules using decision trees; which is highly valuable given that testing each variation of ENPs is tedious and associated with high cost.