HEAVY METALS POLLUTION AT MUNICIPAL SOLID WASTE DUMPSITES IN KANO AND KADUNA STATES IN NIGERIA

Soil samples collected from two major dumpsites each in Kano and Kaduna states were investigated for heavy metals pollution. Each of the dumpsite was divided into north, south, east and west. Four soil samples were collected at a depth of 0-15 cm from each part and pooled to form a composite sample. Soil samples from reserve areas within the same geographical locations as the dumpsites were collected as control. Acid-extractable cadmium (Cd), chromium (Cr), nickel (Ni) and lead (Pb) were determined using 2 M nitric acid solution and atomic absorption spectroscopy. The ranges of Cd, Cr, Ni and Pb levels for all the dumpsites were 0.30–49.8, 5.76–139, 0.39–19.1 and 42.6–9662 mg/kg, respectively. Kano dumpsite 2 was found to pollute most with Cd, Cr and Pb in 50-100 % soil samples collected having concentrations higher than the threshold limits set by regulatory body. Paper and food scraps showed higher percentages in both Kano and Kaduna dumpsites. The soil was high is sand for all the dumpsites implying high leaching potentials of the heavy metals pollutants

Surface Mixed Layer Profile of Physical and Biogeochemical Variables in the Subpolar North-West and -East Atlantic Ocean: A Data-Model Comparison Study

This paper presents a study of physical and biogeochemical variables using numerical model and mixed layer oceanographic data from a 2 - 3 year in situ measurements in the Northwestern and Northeastern sites of the Atlantic Ocean. Model outputs are presented and indicated that very good estimates may be obtained. The outputs showed considerable agreement in reproducing seasonal distributions of pCO2, pCO2-T, pCO2-nonT, mixed layer temperature, and chlorophyll-a in both winter and summer, and therefore provide useful physical and theoretical understanding of their biogeochemistry. The model pCO2 indicated a distinct temporal variability with seasonal changes coinciding with the change in sea surface temperature. It also provides an agreement that there is a strong seasonal cycle of mixed layer parameters filliped by nonthermal and physical factors. As an outgrowth of this work, the pCO2 model outputs affirm the North Atlantic Ocean capacity as an important oceanographic sink for anthropogenic carbon dioxid

HEAVY METALS POLLUTION AT MUNICIPAL SOLID WASTE DUMPSITES IN KANO AND KADUNA STATES IN NIGERIA

Soil samples collected from two major dumpsites each in Kano and Kaduna states were investigated for heavy metals pollution. Each of the dumpsite was divided into north, south, east and west. Four soil samples were collected at a depth of 0-15 cm from each part and pooled to form a composite sample. Soil samples from reserve areas within the same geographical locations as the dumpsites were collected as control. Acid-extractable cadmium (Cd), chromium (Cr), nickel (Ni) and lead (Pb) were determined using 2 M nitric acid solution and atomic absorption spectroscopy. The ranges of Cd, Cr, Ni and Pb levels for all the dumpsites were 0.30–49.8, 5.76–139, 0.39–19.1 and 42.6–9662 mg/kg, respectively. Kano dumpsite 2 was found to pollute most with Cd, Cr and Pb in 50-100 % soil samples collected having concentrations higher than the threshold limits set by regulatory body. Paper and food scraps showed higher percentages in both Kano and Kaduna dumpsites. The soil was high is sand for all the dumpsites implying high leaching potentials of the heavy metals pollutants

Assessment of water and sediment around a lead-acid battery plant dumpsites in South-Western Nigeria

In a quick assessment carried out around dumpsites of a battery manufacturing plant, heavy metals content of sediment, surface water and ground water samples from seven ponds, three streams and a well were assessed using Atomic Absorption Spectrophotometer (AAS). Some physicochemical parameters of the samples were also investigated. Metal concentration in pond and stream sediment samples ranged from 25.71-75,843 μg/gPb, 0.74-4.13 μg/gCd, 32.35-385.31 μg/gCu, 3.17-28.5 μg/gNi, 558.25-908.42 μg/gFe and 10.01-53.59 μg/gZn and these metal concentrations exceeded allowable guidelines for sediment by USEPA. For water samples in general, concentration of metals ranged as Pb(0.001-5.69 mg/L), Cd(0.0006-0.0699 mg/L), Cu(0.001-0.09 mg/L), Ni(0.001-0.38 mg/L), Fe(0.0399-17.099 mg/L) and Zn(0.001-0.14891 mg/L). Physicochemical parameters in water were pH (4.54-7.59), Temperature (25-28 OC), DO (2.49-6.45 mg/L), TS (296-35,100 mg/L), TSS (2.0-281 mg/L), TDS (290-34,800 mg/L), Cl- (12.2-52.5 mg/L), NO3- (3.2-800 mg/L), PO43- (0.14-1.58 mg/L) and SO42- (76.0-5,300 mg/L). Results obtained for TSS, TDS, NO3-, SO42-, Pb, Cd and Fe in water, especially in ponds at Ile-Igbon and Ni in Aweere Stream, exceeded limits set by standard organisations as well as results from similar work

Toxic metal levels in Nigerian electronic waste workers indicate occupational metal toxicity associated with crude electronic waste management practices

The poor management of electronic wastes (e-waste) in Nigeria exposes workers to toxic chemicals in waste electrical and electronic equipment. In this study, we evaluated the toxic metal levels in Nigerians occupationally exposed to e-waste. Whole blood levels of Lead (Pb), Mercury (Hg), Arsenic (As), Cadmium (Cd), and Chromium (Cr) were determined in Nigerian e-waste workers (n=63) and in age-matched non-exposed participants (n=41), using standard electrothermal atomic absorption spectrometry and inductively coupled plasma-mass spectrometry methods. The results showed statistically significant (p<0.01) elevated body burden of toxic metals in e-waste workers (Pb, 0.95 ± 0.00 µmol/L; Cr, 405.99 ± 6.34 µmol/L; Cd, 108.54 ± 1.60 nmol/L; As, 10.09 ± 0.01 µmol/L; and Hg, 25.02 ± 0.14 nmol/L) compared with non-exposed group ((Pb, 0.03 ± 0.00 µmol/L; Cr, 178.44 ± 5.99 µmol/L; Cd, 56.99 ± 1.42 nmol/L; As, 1.02 ± 0.0008 µmol/L; and Hg, 1.62 ± 0.0672 nmol/L). These data indicate that the elevated body burden of toxic metals in the e-waste exposed  population is an indication of occupational metal toxicity associated with crude e-waste management practices in Nigeria. In addition, the potential health implications of exposure to these toxic metals, such as chronic kidney disease, cancer; preceded by genome instability and depressed immune response were highlighted.Keywords: Metal toxicity, e-waste, Nigeria, Occupational exposure

Toxic metal levels in Nigerian electronic waste workers indicate occupational metal toxicity associated with crude electronic waste management practices

The poor management of electronic wastes (e-waste) in Nigeria exposes workers to toxic chemicals in waste electrical and electronic equipment. In this study, we evaluated the toxic metal levels in Nigerians occupationally exposed to e-waste. Whole blood levels of Lead (Pb), Mercury (Hg), Arsenic (As), Cadmium (Cd), and Chromium (Cr) were determined in Nigerian e-waste workers (n=63) and in age-matched non-exposed participants (n=41), using standard electrothermal atomic absorption spectrometry and inductively coupled plasma-mass spectrometry methods. The results showed statistically significant (p<0.01) elevated body burden of toxic metals in e-waste workers (Pb, 0.95 \ub1 0.00 \ub5mol/L; Cr, 405.99 \ub1 6.34 \ub5mol/L; Cd, 108.54 \ub1 1.60 nmol/L; As, 10.09 \ub1 0.01 \ub5mol/L; and Hg, 25.02 \ub1 0.14 nmol/L) compared with non-exposed group ((Pb, 0.03 \ub1 0.00 \ub5mol/L; Cr, 178.44 \ub1 5.99 \ub5mol/L; Cd, 56.99 \ub1 1.42 nmol/L; As, 1.02 \ub1 0.0008 \ub5mol/L; and Hg, 1.62 \ub1 0.0672 nmol/L). These data indicate that the elevated body burden of toxic metals in the e-waste exposed population is an indication of occupational metal toxicity associated with crude e-waste management practices in Nigeria. In addition, the potential health implications of exposure to these toxic metals, such as chronic kidney disease, cancer; preceded by genome instability and depressed immune response were highlighted

Surface Mixed Layer Profile of Physical and Biogeochemical Variables in the Subpolar North-West and -East Atlantic Ocean: A Data-Model Comparison Study

This paper presents a study of physical and biogeochemical variables using numerical model and mixed layer oceanographic data from a 2 - 3 year in situ measurements in the Northwestern and Northeastern sites of the Atlantic Ocean. Model outputs are presented and indicated that very good estimates may be obtained. The outputs showed considerable agreement in reproducing seasonal distributions of pCO2, pCO2-T, pCO2-nonT, mixed layer temperature, and chlorophyll-a in both winter and summer, and therefore provide useful physical and theoretical understanding of their biogeochemistry. The model pCO2 indicated a distinct temporal variability with seasonal changes coinciding with the change in sea surface temperature. It also provides an agreement that there is a strong seasonal cycle of mixed layer parameters filliped by nonthermal and physical factors. As an outgrowth of this work, the pCO2 model outputs affirm the North Atlantic Ocean capacity as an important oceanographic sink for anthropogenic carbon dioxid