Nanomaterials describe, in principle, materials of which a single unit is sized (in at least one dimension) between 1 to 1000 nanometres (10−9 meter) but usually is 1 to 100 nm (the usual definition of nanoscale).
Human activities have strongly modified the biogeochemical cycles of metallic trace elements (MTEs) increasing their fluxes towards and between surface environments. New isotope data has fostered better models of MTE sources, transfer and reactivities in dynamic and multi-sources systems, as required for targeting emission controlled strategies to combat origins and consequences of metal contamination.