Investigating municipal solid waste generation and management in Ilorin for possible integrated waste-management system

Journal of Material Cycles and Waste Management - The municipal solid waste generated in Ilorin is so enormous that the management method available cannot sufficiently cater for it. This is evident...     

Speciation study of lead and manganese in roadside dusts from major roads in Ile-Ife,South Western Nigeria

A speciation study of Pb and Mn in roadside dust along major roads in Ile-Ife, South Western Nigeria, was investigated. Pb and Mn values obtained by total digestion ranged from 22.23 ± 3.52 to 43.48 ± 3.05 μg/g and 35.93±0.15 to 83.76 ± 0.06 μg/g, respectively. The results of speciation analysis of Pb and Mn in the samples showed that the mean levels of these metals in the various fractions followed the order: organic matter>residual>Fe-Mn>carbonate>exchangeable and organic matter-bound>exchangeable>carbonate-bound>residual>Fe-Mn oxide-bound respectively. The speciation study therefore revealed that most of the Pb and Mn were associated with the organic matter fraction and that they were least available in the exchangeable and Fe-Mn oxide fractions, respectively. The apparent mobility and potential bioavailability for these metals in the road dust was Mn>Pb. There is a significant difference between the means of Pb and Mn in the road dust of the study area at p≤0.05, which strongly suggests that they may not have come from the same source; different sources may be responsible, which may be anthropogenic, such as tyre wear, vehicular emission, brake linings and natural.     

Evaluation of geochemical characteristics and health effects of some geophagic clays southern Nigeria

The geochemical characteristics of geophagic clays from Calabar and Okon-Eket, southern Nigeria were evaluated to determine their quality and the possible health effects of their consumption. The study involved the measurement of the pH, electrical conductivity (EC) and total dissolved solids (TDS) of the slurried clay samples soaked in distilled water for 48 h using digital multi-parameters probe as well as the elemental and mineralogical analyses of twenty geophagic clay samples for elemental and mineralogical constituents using both the ICP-MS and XRD, respectively. Medical data were also mined from medical facilities within the area in addition to the administering of questionnaire to adults involved in the geophagic practices in order to determine their justification for the practice as well as their and clay preferences. Results of physicochemical measurement revealed that the pH range of the samples ranges from 3.9 to 6.9 and 6.5 to 7.0; EC 0.3–377.7 and 0.12–82.38 µS/cm; TDS 1.98–2,432.65 and 0.08–52.95 mg/L for consumed and non-consumed clay, respectively. The elemental analyses revealed that the concentration of some potential harmful elements, PHEs, exceeded the recommended dietary intake by humans. This is especially true for Cu (9.1–23 ppm), Pb (16.7–55.6 ppm), Zn (13–148 ppm), Ni (11.1–46.4 ppm), Co (1.8–21.7 ppm), Mn (16–338 ppm), As (BDL-15 ppm) and Cd (BDL-0.2 ppm). The predominant phases established in the clay samples are quartz and kaolinite, while the minor minerals were montmorillonite and muscovite in all the clay samples. Respondents revealed that capacity for relief from gastrointestinal problems believes in the curative power to cure skin infections and cultural reasons as main justification for the geophagic practices. This is, however, not in conformity with information gleaned from the medical records which still indicated that the prevalent diseases in the area still include gastrointestinal problems in addition to malaria, hypertension and cardiac failure with minor cases of respiratory tract infections. The high concentrations of the PHEs may be responsible for or contribute in part to the prevalence of hypertension, cardiac failures and gastrointestinal problems within the study areas. Though the kaolinite present in the geophagic clays makes them suitable for use as traditional antacids; however, the toxic trace element concentrations and significant quartz content will most likely mask the beneficial effects of such kaolinite.     

Outdoor air particle-bound trace metals in four selected communities in Ibadan,Nigeria

Trace metal concentrations were determined in particulate matter (PM₁₀) in ambient air of four purposively selected residential areas in Ibadan, Nigeria namely Bodija market (BM), Ojo Park (OP), Oluyole Estate (OE) and University of Ibadan (UI). PM₁₀ was determined in the morning (7–10 a.m.) and afternoon (2–5 p.m.) for 12 weeks in the dry season months of January–March using a volumetric sampler following standard procedures and levels compared with WHO guideline limits. Glass-fibre filter papers exposed to the particulate matter were digested using appropriate acid mixtures, and the digest analysed for trace metals including Ni, Cr, Mn, Zn, and Pb using ICPMS method and levels compared with WHO limits. Data was analysed using ANOVA and Pearson correlation test at 5 % level of significance. The highest mean PM₁₀ concentrations 502.3 ± 39.9 μg/m³ were recorded in the afternoon period at BM, while the lowest concentration 220.6 ± 69.9 μg/m³ was observed in the morning hours at UI. There was a significant difference between the PM₁₀ levels across the various locations (p < 0.05), and all the levels were higher than WHO limit of 50 μg/m³. The highest levels of Ni, Zn and Pb were recorded at BM, which also had the highest PM₁₀ burden. The trend in Pb levels across the locations was BM > UI > OP > OE with the highest level 5.70 μg/m³ in BM nearly fourfolds WHO limits of 1.5 μg/m³. There was a significant correlation between PM₁₀ and Ni (p < 0.05).Urban communities with increased human activities especially motor traffic recorded both higher levels of PM₁₀ and toxic trace metals. There is need to carry out source apportionment to establish the origin of these trace metals in future studies.     

Contamination indices and heavy metal concentrations in urban soil of Ibadan metropolis, southwestern Nigeria

An assessment was conducted on soils of Ibadan metropolis using geochemical approach in order to establish the concentration of heavy metals and develop geoaccumulation index maps. Petrographic studies and X-ray diffractograms showed that soils of Ibadan were derived from the weathering of the bedrocks. The concentrations of Cu, Pb, and Zn were found to be greater in soils more than the background. Positive correlation occurred between Cu, Pb, and Zn indicated a common anthropogenic source in the soil while Mn, Cr, and Ni were found to be naturally enriched. The geoaccumulation index maps revealed significant enrichment factor (Ef > 20) and index of geoaccumulation (Igeo) beyond class four (heavily contaminated) for Cu, Pb, and Zn in densely populated and industrial areas, whereas Cd is enriched in sparsely populated areas, agricultural areas and a few spots in densely populated areas.     

The Sagamu cement factory,SW Nigeria: Is the dust generated a potential health hazard?

The aim of this study was to assess the heavy metal content of the dust generated by the Sagamu cement factory and its attendant health hazards on the immediate environment, especially on the inhabitants of the area. A total of 25 samples were collected and analyzed using inductively coupled plasma-optical emission spectrometry. Records of medical ailments associated with heavy metal toxicity were also compiled from the Obafemi Awolowo Teaching Hospital situated in the town.The results for some of the selected heavy metals showed the following pattern: limestone: Cd (n.d.-1.7 ppm), Pb (42–48 ppm), Cu (3.0–11 ppm), Zn (7.0–53 ppm) and Ni (3.0–8.0 ppm); shale: Cd (0.3–1.1 ppm), Pb (17–22 ppm), Cu (2.0–11 ppm), Zn (17–147 ppm) and Ni (3.0–18 ppm); dusts: Cd (0.5–0.7 ppm), Pb (32–52 ppm), Cu (2–16 ppm), Zn (5–152 ppm) and Ni (2–17 ppm); soils: Cd (0.5–1.1 ppm), Pb (28–49 ppm), Cu (22–35 ppm), Zn (43–69 ppm) and Ni (13.0–17 ppm). High levels of heavy metals were found in the rocks and soils. We propose that the high levels of metals in the dust and soil were acquired from the raw materials used by the cement factory and from active industrial discharge from this same factory. Medical records and the current health situation of the local residents in the study area reveal that there have been increases in the prevalence of diseases linked to heavy metal toxicity in the environment, especially those related to dust generation.     

Medical waste management in Ibadan, Nigeria: obstacles and prospects

Quantification and characterization of medical waste generated in healthcare facilities (HCFs) in a developing African nation has been conducted to provide insights into existing waste collection and disposal approaches, so as to provide sustainable avenues for institutional policy improvement. The study, in Ibadan city, Nigeria, entailed a representative classification of nearly 400 healthcare facilities, from 11 local government areas (LGA) of Ibadan, into tertiary, secondary, primary, and diagnostic HCFs, of which, 52 HCFs were strategically selected. Primary data sources included field measurements, waste sampling and analysis and a questionnaire, while secondary information sources included public and private records from hospitals and government ministries. Results indicate secondary HCFs generate the greatest amounts of medical waste (mean of 10,238 kg/day per facility) followed by tertiary, primary and diagnostic HCFs, respectively. Characterised waste revealed that only approximately 3% was deemed infectious and highlights opportunities for composting, reuse and recycling. Furthermore, the management practices in most facilities expose patients, staff, waste handlers and the populace to unnecessary health risks. This study proffers recommendations to include (i) a need for sustained cooperation among all key actors (government, hospitals and waste managers) in implementing a safe and reliable medical waste management strategy, not only in legislation and policy formation but also particularly in its monitoring and enforcement and (ii) an obligation for each HCF to ensure a safe and hygienic system of medical waste handling, segregation, collection, storage, transportation, treatment and disposal, with minimal risk to handlers, public health and the environment.     

Hematoxicity and hepatoxicity attributed to zinc and cadmium in the Norwegian rat

This study was carried out to determine changes in the blood and liver of rats given oral doses of cadmium (Cd) and zinc (Zn). Thirty 3 month old rats were kept six to a compartment in a well-demarcated five compartment cage labeled A, B, C, D, and E. After 2 weeks of acclimatization, and with ad libitum administration of water and feed, group A and B rats were, respectively, exposed to 100 mg CdSO₄ and 2200 mg ZnSO₄, respectively, mixed with their feed. Group C rats were fed with a combination of 100 mg CdSO₄ and 2200 mg ZnSO₄ mixed with their feed, while group D rats were exposed to 100 mg CdSO₄ mixed with their feed for 48 h, and after they were given 2200 mg ZnSO₄ for 96 h. Group E rats served as control and were fed a normal diet. Analysis of blood samples after 5 days showed that in rats of groups A, B, C, and D, WBC count increased from 6800 to 12,400 mm^?3 and platelets from 26,000 to 88,000 mm^?3. Reduction in blood counts were found for RBC from 13.8 to 4.7 × 10⁶ mm^?3, hemoglobin from 15.6 to 11.4 dL^?1, and PCV from 47 to 34%. ESR was the same 1.0 mm h^?1 in all groups. Severe damage to the liver was also shown by severe degeneration of hepatocytes and increase in Kuppfer cells. The above observations were mildest in the liver of group C rats. A reduction of body weight was observed in all treatment groups. Cd and Zn were found to be hematoxic and hepatotoxic in the Norwegian rat with Cd exhibiting greater toxicity than Zn. Toxicity of Cd was suppressed by Zn only when both metals were admistered at the same time, but a delay in intake of Zn (after 48 h) had little effect on Cd toxicity.