Antibiotic residues in Ghanaian environmental systems: sources, distribution patterns, and public health implications

Antibiotic contamination has become an emerging environmental and public health concern in Ghana, with important implications for ecosystem integrity and antimicrobial resistance (AMR). This review synthesises current evidence on the occurrence, spatial distribution, sources, and ecological implications of antibiotic residues across Ghanaian environmental matrices, including surface water, groundwater, sediments, soils, hospital effluents, landfill leachates, and aquaculture systems. A systematic review of studies published between 2000 and 2026 was conducted, drawing on peer-reviewed literature, institutional reports, and environmental monitoring studies. In total, 46 studies met the inclusion criteria and were included in the final synthesis. The findings indicate that antibiotic contamination is widespread across multiple environmental compartments, although concentrations vary substantially by matrix and location. Hospital effluents and landfill leachates consistently recorded the highest contamination levels, with amoxicillin concentrations reaching 8760 µg/L in hospital wastewater and penicillin concentrations as high as 67,420 µg/L in landfill leachates. Major contamination hotspots were identified in Kumasi, Sunyani, and Sefwi Wiawso, where intense healthcare activities, inadequate wastewater treatment, and poor waste management practices contribute significantly to environmental pollution. Lower but persistent concentrations were also detected in rivers, reservoirs, sediments, and aquaculture systems, indicating chronic environmental exposure. The review further demonstrates that contaminated environmental systems serve as reservoirs for antibiotic-resistant bacteria and resistance genes, increasing the potential for environmental dissemination of AMR. Strengthened environmental surveillance, improved wastewater treatment, and integrated regulatory frameworks are urgently needed to mitigate antibiotic pollution in Ghana.