Environmental assessment of volcanic-ash-based alkali-activated binders: Oxyanion leaching and marine bioassay responses

= 56.90%), with developmental inhibition correlating with elevated oxyanion concentrations. These results demonstrate that VA-based AABs are technically viable but exhibit activation-dependent environmental behaviour that is not detected by bacterial assays alone. Results support integrating sensitive marine invertebrate bioassays into regulatory and weight-of-evidence frameworks and provide guidance for the sustainable management of volcanic residues and the deployment of alkali-activated materials in coastal and marine-influenced environments.