Metal bioaccumulation prediction via QSPR-q-RASPR synergy and cross-species risk analysis

Abstract

The bioconcentration factor (BCF) is a critical parameter for evaluating the ecological impact of chemical pollutants, reflecting their potential to accumulate in living organisms, particularly through respiratory pathways in aquatic ecosystems. Pollutants such as nanomaterials, organic compounds, metals, metal halides, and metal oxides can bioaccumulate within ecosystems, posing significant threats to biodiversity and ecosystem stability. For instance, elevated BCFs of metal oxides in aquatic environments have been linked to oxidative stress in marine invertebrates, highlighting the urgency of accurate bioaccumulation assessments. This study employed advanced Quantitative Structure–Property Relationship (QSPR) and Quantitative Read-Across Structure–Property Relationship (q-RASPR) modeling techniques to evaluate the bioconcentration potential of metals, metal halides, and metal oxides across diverse species. Additionally, Species bioaccumulation Sensitivity Distribution (SbSD) models were applied to analyze sensitivity patterns across 10 species groups, including algae, amphibians, fish, crustaceans, and molluscs, using BCF data. Key chemical descriptors, including total electronegativity, crystal ionic radius, and molecular bulk, significantly influence bioaccumulation patterns. Total electronegativity and crystal ionic radius negatively impact bioconcentration in algae. Molecular bulk positively correlates with accumulation in crustaceans. In fish, bioaccumulation is positively associated with electron count but negatively correlated with crystal ionic radius. The q-RASPR models consistently outperformed traditional QSPR approaches, offering robust predictive frameworks and deeper mechanistic insights into bioaccumulation processes. To support the application of QSPR and q-RASPR models, the authors offer access to the NanoSens CalTox platform at https://nanosens.onrender.com/pages/apps/, serving as a valuable resource for researchers, industry professionals, and regulatory authorities to conduct informed environmental and ecological risk assessments.