Analysis of potentially toxic elements from selected mechanical workshops using the geo-accumulation index and principal component analysis in Omu-Aran Community, Nigeria.

Bioaccumulation of potentially toxic elements in soil threatens public health and the ecosystem. This study aims to assess the concentration of potentially toxic elements (chromium (Cr), lead (Pb), iron (Fe), arsenic (As), and cadmium (Cd)) in selected automobile workshop premises in Omu-Aran, Nigeria. Forty-eight samples were collected at a depth (15 cm) in six locations, including a control point. Acid digestion was carried out to prepare the soil samples before assessing their concentration via an atomic absorption spectrophotometer. Geo-accumulation index (Igeo) was used to classify the level of contamination. Statistical analysis, which includes principal component analysis (PCA) and Pearson's correlation, was also determined. The difference in concentration was determined using ANOVA. In the study area, the lowest observed concentration values for Cr, Pb, Fe, As, and Cd, which are 0.246 ± 0.002 mg/kg, 0.178 ± 0.001 mg/kg, 90.715 ± 0.038 mg/kg, 0.012 ± 0.004 mg/kg, and 0.078 ± 0.004 mg/kg, respectively, are relatively higher than observed for the control. The observed potentially toxic elements fall within three Igeo based on Muller's interpretation; heavily to extremely contaminated (Cd), moderately to heavily contaminated (Pb, Cr, and As), and uncontaminated to moderately contaminated (Fe). PCA shows that two principal components (PC) account for up to 91.052% of the original mean dataset variability. PC1 explains 67.723% of the total variance associated with Cd, Cr, Fe, Pb, and As, indicating anthropogenic is the primary source of these potentially toxic elements. The PC2 accounted for 23.329%, with Pb and As significant contributors. Cadmium contamination of soil was the most influential, with an Igeo value ranging from 4 to 5. Residents in the polluted region face considerable health risks from potentially toxic elements.

Solid waste management problems in secondary schools in Ibadan, Nigeria.

Inappropriate solid waste management practices in schools in less-developed countries, particularly in major urban communities, constitute one of the major factors leading to declining environmental health conditions. The objective of the authors' descriptive, cross-sectional study was to assess solid waste management problems in selected urban schools in Ibadan, Nigeria. Eight secondary schools with average pupil populations not less than 500 per school were selected randomly. Four hundred questionnaires (50 per school) were administered. In addition, an observational checklist was used to assess the physical environment. Paper and plastics were the most frequently generated wastes. Common methods of solid waste disposal reported were use of dustbins for collection and open burning. Major problems perceived with current refuse disposal methods by the study students were odors, pest infestation, and spillages. Littering and spillages of solid waste were also common features reported. Data suggested inadequate waste management facilities and practices in study schools. The lack of refuse bins may have contributed to waste spillages and the burning practices. Odors may have arisen from both the decay of overstored organic waste rich in moisture and emissions from refuse burning. This scenario poses a community environmental health nuisance and may compromise school environmental quality.