Assessment of Environmental Contamination and Pollutant Exposure Pathways Among Households Surrounding Informal Solid-Waste Disposal Sites in Obio/Akpor, Rivers State

Informal solid-waste disposal is a major environmental and public-health concern in rapidly urbanizing communities. This study assessed informal solid-waste disposal practices and associated environmental and potential public-health risks in Obio/Akpor Local Government Area, Rivers State, Nigeria. A cross-sectional study was conducted using structured household questionnaires and environmental assessment of air, soil and water around informal waste-disposal sites. Of 427 questionnaires administered, 389 were valid, representing a 91.1% response rate. Descriptive statistics were used to assess waste-management practices, household proximity and reported exposure pathways, while environmental measurements were compared with relevant guideline values. Informal disposal was common, with 35.2% of households using informal dumpsites, 22.9% practising open burning and 12.3% disposing waste through drains or waterways. Overall, 70.4% relied on these unsafe disposal practices, while 61.2% of households were located within 250 m of informal disposal sites. Mean PM₂.₅ (48.6 µg/m³) and PM₁₀ (92.4 µg/m³) exceeded WHO 24-hour guideline values. Soil lead (84.6 mg/kg), cadmium (3.8 mg/kg) and total petroleum hydrocarbons (1,850 mg/kg) exceeded adopted reference values. Water showed acidic pH (5.91), elevated lead (0.028 mg/L), cadmium (0.009 mg/L), iron (0.87 mg/L) and E. coli (146 CFU/100 mL). Reported exposure pathways included offensive odour (77.6%), dust/particulates (71.5%), smoke (62.0%), soil/waste contact (50.9%) and potentially contaminated water (42.9%). Informal waste disposal in Obio/Akpor is associated with environmental contamination and multiple plausible exposure pathways. Improved formal waste collection, elimination of open dumping and burning, environmental monitoring, and protection of water and drainage systems are recommended.