Heavy metal contamination driven by artisanal gold mining in the Ile-Ife–Ilesha Schist Belt, Nigeria: Geospatial assessment of pollution sources and hotspots - AbdulGaniyu Isah; Olukole Adedeji Akinbiyi; Ayodeji Hansen-Ayoola; Nelson Chinaka Ayajuru; Taoreed Adekunle Muraina; Fasilat Olajumoke Rafiu (Environmental Monitoring and Assessment, 2025)