Assessment of the Environmental Impacts of Solous Municipal Solid Waste Landfills using Soil Properties and Earthworms (Eudrilus eugeniae)

This study assessed the effects of Solous Municipal Solid Waste Landfills on soil properties, heavy metal contamination and macro-invertebrates (earthworms). Soil and earthworm samples were collected from Solous municipal solid waste landfills with reference samples obtained from the Botanical Garden, University of Lagos and taken to the laboratory for analyses using standard methods. Results showed that pH and organic matter values of soil samples from the landfills ranged from 8.51±0.88 to 9.85±0.02 and 5.79±0.53 % to 7.11±1.19 % respectively, and they were statistically (P < .05) higher than the values of the reference samples. Most of the assessed heavy metals in soil and earthworms from the landfills were significantly (P < .05) higher when compared to the reference samples. The antioxidant enzymes and lipoperoxidation product levels were significantly (P < .05) higher in earthworms from most of the landfills in relation to the reference samples. The mean total protein concentrations in annelids from the landfills were lower than the mean concentration in the reference samples, however, only those from two of the landfills (Solous B and C) were significant (P < .05). Histological studies showed that the clitella of earthworms from the landfills had abnormalities such as disruption of body wall muscle layers, cellular degeneration, oedematous longitudinal muscle, and dark brown pigments. Solous Landfills had an obvious effect on the assessed abiotic and biotic parameters, and could be a source of heavy metal pollution in nearby vicinities especially their groundwater sources and surface water.

Keywords
Biochemical markers; Bioindicator; Eudrilus eugeniae; Heavy metals; Landfill; Soil properties.