Physicochemical properties and microbial biomass of carbon and nitrogen at the electronic waste disposal site in Alaba International Market, Lagos State, Nigeria.

Abstract

The challenge of electronic waste in Lagos State manifests primarily through soil and water pollution arising from indiscriminate disposal practices. Poor handling and disposal of e-waste expose individuals to hazardous substances, often resulting in respiratory and dermatological health issues. This study examined the physicochemical properties and microbial biomass of carbon (C) and nitrogen (N) of soils at e-waste dumpsites in Alaba International Market, Lagos, Nigeria. A total of 75 soil samples were collected from multiple sampling points, alongside three control samples, and analyzed using standard procedures. The results indicate no significant(p<0.05) differences in most physicochemical properties, with the exception of electrical conductivity. Similarly, microbial biomass showed no significant variation between e-waste and control soils, although e-waste soils contained higher levels of organic matter and microbial biomass. All soil samples, both from e-waste sites and control sites, were consistently classified as sandy in texture according to the USDA (United States Department of Agriculture) classification system. The control soils exhibited the lowest pH (H₂O) value of 6.71, which differed significantly (P<0.05) from the e-waste soils, whose pH ranged from 7.48 to 7.54; comparable patterns were observed in pH values measured with CaCl₂. Organic carbon content varied between 1.92 and 2.19 g/kg, while organic matter in the control soil was 3.38 g/kg, compared with 3.31–3.78 g/kg in the e-waste soils. Microbial biomass C and N showed similar values across both control and e-waste soils. Overall, this study provides critical insights into the environmental impacts of e-waste on soil quality, offering a basis for evidence-based decision-making, policy development, and the formulation of sustainable strategies to safeguard the health of present and future generations in Lagos State, Nigeria.