Antimicrobial Resistance Spread Through Medical Waste: Environmental Contamination and Public Health Implications in Urban Nigeria

Antimicrobial resistance (AMR) represents a critical global health threat, with medical waste management serving as an underexplored vector for resistance gene dissemination. This study examines the relationship between inadequate medical waste management and AMR propagation in Lagos, Nigeria's megacity of over 20 million inhabitants. Through mixed-methods assessment of seven healthcare facilities, we documented significant deficiencies: only 61% proper waste segregation at source, 33.3% correct identification of pharmaceutical waste protocols, storage durations of 5–10 days (versus recommended 24–48 hours), and widespread mixing of antimicrobial-containing waste with general streams. Facilities generated 215.56 kg/day of medical waste (0.181 kg/bed/day average), with pharmaceutical waste comprising 5–8% yet receiving no specialized treatment beyond standard hydroclave sterilization - inadequate for degrading antimicrobial compounds. Analysis reveals multiple environmental contamination pathways: wastewater discharge, storage site leachate, transport spillage, and inadequate final disposal exposing waste handlers, communities, and environmental matrices to antimicrobial residues and resistant bacteria. Nigeria's fragmented policy framework, characterized by weak enforcement and absent AMR-specific provisions, exacerbates these challenges. Cost constraints, limited technical capacity, and insufficient training emerged as primary implementation barriers. This study proposes an integrated framework combining enhanced segregation, AMR-targeted treatment technologies, environmental monitoring, strengthened regulatory enforcement with AMR provisions, and community-based approaches. Findings have significant implications for public health policy in resource-constrained urban settings where inadequate waste infrastructure creates conditions for AMR amplification and dissemination through environmental pathways.