Document Type : Review Paper

Authors

• Ovaoiza A. Joy ¹
• Onyenweife Ifesinachi Geraldine ²
• Abdulmalik Onimisi Danga ³

¹ Kogi Polytechnic, Lokoja

² Chukwuemeka Odumegwu Ojukwu University

³ Confluence University of Science and Technology

Abstract

Global waste production is estimated to increase to 3.4 billion metric tons by 2050, of which 69% of waste disposal, especially in Sub-Saharan Africa, is discharged through unlined landfills/open dumpsites. This study examines the toxic effects of unlined landfills/open dumpsites on environmental and public health. Based on geophysical and hydrochemical data from literature, the study reveals a low subsurface resistivity between 4.2 – 34 Ωm around dumpsite-affected areas, indicating severe groundwater contamination, while a high subsurface resistivity >120 Ωm noted at control points suggests little or no contamination, depending on the nature of the terrain. Samples from surface and groundwater registered elevated heavy metal (HM) levels beyond WHO limits, with groundwater varying between 0.005 – 2.430 mg/L, surface water recorded a higher concentration of HMs, with the highest concentration (≤7.5 mg/L) noted in the Challawa River, Nigeria, where waste materials are discharged into the river at will. Methane released from landfill gas amounts to 40 million metric tons annually, which accounts for 7.5% of global methane emissions. Temperatures observed with landfills ranged between 32°C and 60°C, increasing greenhouse gas emissions and global warming. Such practices result in the release of toxic gases and heavy metal leachates, which pose serious long-term threats to the environment as well as to public health. The adoption of clean technologies such as waste-to-energy solutions and sanitary landfills is a major constraint, but necessary in these fast-growing urban areas. In conclusion, the current unlined landfills/open dumpsites practice, especially in developing nations, is unsustainable. A need for a shift towards sanitary landfills, integrated waste management, recycling, and climate-resilient policies is imperative to mitigate this pervasive contamination and steer towards a sustainable, waste-conscious future

Keywords

• waste management
• leachate plumes
• hazardous impacts
• groundwater
• public health