Heavy Metal Pollution in Mining Ecosystems: An Emerging Driver of Environmental Resistomes and Antimicrobial Resistance

Antimicrobial resistance (AMR) is a global health threat that continues to concern scientists because it can be driven not only by antibiotic misuse but also by environmental factors. Mining-related heavy metal pollution can apply strong selective pressure on microbial communities, leading to a significant increase and spread of antibiotic resistance genes (ARGs) in the environmental ecosystems. Here, we critically review the emerging role of mining environments as hotspots of environmental resistomes and the mechanisms by which heavy metal contamination drives co-selection of antibiotic resistance. There is also evidence that mining environments, such as AMD systems, mine tailings, contaminated sediments, and mining-impacted soils, harbor highly diverse microbiomes enriched with different resistance determinants. Heavy metals such as copper, zinc, cadmium, mercury, and arsenic promote ARG co-selection through co-resistance, cross-resistance, and co-regulation mechanisms. Widespread co-occurrence of metal- and antibiotic-resistance genes on mobile genetic elements such as plasmids, integrons, and transposons has been demonstrated in metagenomic studies. Environmental dissemination pathways, such as water systems, agricultural soils, wildlife interactions, and occupational exposure, may promote the spread of resistance genes outside mining sites. Mining ecosystems are underrecognized and potentially important reservoirs of antimicrobial resistance. This review highlights the importance of integrating environmental resistome surveillance into existing global AMR monitoring frameworks to understand underlying ecological drivers of resistance evolution. Tackling metal-driven antibiotic resistance requires innovative, solution-based interdisciplinary research, enhanced environmental screening and soil and water testing practices, and sustainable mining practices within the One Health paradigm.