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.     

Survey of Levels of Phthalate Ester Plasticizers in a Sewage Lagoon Effluent and a Receiving Stream

In this study, samples from a sewage treatment lagoon and those from a receiving stream were analyzed for their phthalate esters content. Knowledge of the distribution of ubiquitous phthalate esters in the sewage lagoon and the receiving stream was necessary because of the reports of their subtle toxicity to aquatic biota and humans. Liquid–liquid extraction, Clean-up experiment and High Performance Liquid Chromatography (HPLC) were the methods employed for the quantitative determination of the Phthalates. A study of uncontaminated water was done to establish blank levels. The sewage lagoon and the receiving stream were grossly polluted as several phthalate ester plasticizers: DMP, DEP, DPhP, DBP, DEHP, DOP and DINP were found present at monthly mean levels of between 24.02 mg/L and 139.25 mg/L in the sewage treatment lagoon and 10.41 mg/L and 80.53 mg/L in the receiving stream. The results showed higher levels of phthalate esters in the sewage lagoon compared to the receiving stream. The sewage lagoon was identified as a pollution point source into the receiving stream. Levels of phthalates obtained from the receiving stream are much higher than the water criteria of 3 μg/L phthalates recommended by the United States Environmental Protection Agency (USEPA) for the protection of fish and other aquatic life in water and the Suggested No-Adverse Effect Levels (SNAEL) of 7.5–38.5 μg/L for drinking water. This should give cause for great environmental concern. Peoples’ health downstream is at stake and so is the ‘health’ of the ecosystem.     

Determination of phthalate ester plasticizers in the aquatic environment of Southwestern Nigeria

Water from the Lagos, Oyo, Osun, Ondo, and Delta states of Nigeria and the cities' water treatment plants had been analized for the presence of ubiquitous phthalate esters using liquid chromatography. Extraction with CH₂Cl₂ and liquid chromatography was used for compound separation. Several phthalate esters, dimethyl- (DMP), diethyl- (DEP), and di-n-butyl- (DBP) were found present at levels of 10 mg L⁻¹ to 1472 mg L⁻¹ in river water and 91 mg L⁻¹ to 1219 mg L⁻¹ in tap water from the cities' water treatment plants. A study of uncontaminated water was done to establish blank levels.     

Study of trace elements in urine of some Nigerian medical patients

In this study, trace element concentrations were determined in urine samples of patients with kidney and liver conditions from the Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife Nigeria. Urine samples from 80 patients whose ages ranged from 15 to 79 were used for the trace metals analysis. Variation of the trace metals including lead (Pb), cadmium (Cd), mercury (Hg), zinc (Zn), copper (Cu), and manganese (Mn) in urine samples were correlated with respect to gender, age, professions, personal habits and patients’ conditions. The levels of Pb in the urine samples of both male and female patients were found to be generally higher than those of Cd, Hg, Zn, Cu, and Mn. Highest levels of Pb and Cd were found in patients who smoked and drank and those with various kidney and liver conditions. Most of the trace metals except Mn occurred at levels that are deleterious to human health as they are above the standard threshold values expected in normal human urine, and raised cause for concern.     

Assessment of polybrominated diphenyl ethers in sediment of Asunle stream of the Obafemi Awolowo University,Ile-Ife,Nigeria

Assessment of levels of polybrominated diphenyl ethers (PBDEs) from the sediment of Asunle stream, an adjourning stream of the Obafemi Awolowo University dumpsite, has been carried out. Sediment samples were collected from the stream at six locations for a period of 8 months, composed of 4 months each of wet (May–Aug) and dry (Nov–Feb) seasons. Soxhlet extraction was employed for the isolation of all the target compounds from the sediment samples. Extracts were further subjected to multi-layer column chromatography employing different forms of silica gel. The prepared samples were analyzed using GC-MS. The overall mean concentrations of the total PBDEs ranged from 1.80 to 9.46 ng/g. The results showed that the concentrations of the PBDEs were slightly higher during the wet season than those during the dry season. In all the studied locations, BDE28, BDE47, BDE99, BDE100, BDE153, and BDE154 were detected in all the sediment samples at concentrations that ranged from 0.73 to 10.43 ng/g. Results of this study indicated that BDE153 was the major pollutant of the Asunle stream sediments.     

Heavy metals pollution in a sewage treatment oxidation pond and the receiving stream of the Obafemi Awolowo University, Ile Ife, Nigeria

This work centered on a 1-year evaluation campaign of point source pollution from a sewage treatment oxidation pond and its receiving stream. Water samples were collected from the sewage treatment oxidation pond and the receiving stream during July 2002 and June 2003. Concentrations of heavy metals were determined using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) after a triple acid digestion of samples using open beaker method. Generally, the results showed high levels of toxic metals such as Cd, Pb, As, Al, Cr, Mn, Co, and Fe in the influent and effluent samples as well as in the receiving stream. The annual mean concentration of metals in the sewage samples ranged from 11.90 to 16.05, 64.96 to 88.27, 38.91 to 76.35, 17.46 to 24.45 mug/L for Cd, As, Pb, Co, and 4.31 to 8.77, 1.71 to 2.45, 0.46 to 0.74 and 13.82 to 20.47 mg/l for Al, Cr, Mn and Fe, respectively; while in the receiving stream, the concentrations were between 6.89 to 10.45, 35.50 to 59.26, 22.85 to 35.94, 11.33 to 18.83 mug/l for Cd, As, Pb, Co, and 1.99 to 3.49, 1.35 to 2.08, 0.21 to 0.48, and 8.93 to 14.15 mg/l for Al, Cr, Mn and Fe, respectively. The discharge of the effluent from the sewage pond into the receiving stream has therefore led to increase in the concentrations of some heavy metals downstream, thus impacting the receiving stream negatively and could pose a serious health hazard to aquatic ecosystems and humans particularly for rural dwellers and peasant farmers downstream that utilize the water from the receiving stream for various domestic and agricultural purposes untreated.     

High level leaching of heavy metals from colorful ceramic foodwares: a potential risk to human

Environmental Science and Pollution Research - Ceramic foodwares are among the products used by people on daily basis without being cautious of exposures to heavy metals through possible leaching...     

Analysis of Cd,Cu, Pb,Zn, Hg and Mn in kidneys and liver from human cadavers – A case study in South Western Nigeria

In this study, autopsy tissue samples from human liver and kidneys were analysed for Cd, Cu, Pb, Zn, Hg and Mn in 25 subjects (16 males and 9 females) ranging in age from 2 to 70 years. Tissue samples that were pathologically normal were obtained at postmortem and concentrations of metals were determined. In both kidneys and liver, the concentrations of metals followed the order Cd > Hg > Pb > Zn > Mn > Cu irrespective of gender and age group, except in female kidneys where the order was Cd > Pb > Hg > Zn > Mn > Cu. Generally, males had higher concentrations of metals in both the kidneys and liver. Significant correlations of the metals were found in kidney and liver tissues.