Chlorinated Hydrocarbons in Marine Female Fishes of Lagos Lagoon

Three female fish species of Snapper (Lutjanus goreensis), Herring (Sardinella maderensis) and Oarfish (Regalecus glesne) were sampled from Lagos Lagoon during the dry and wet seasons of 2008 and 2009 and subjected to cold extraction and clean-up procedure. Their muscle tissues were analysed for chlorinated hydrocarbons because they can concen trate pesticide residues from sediments and water. The identification and quantitation of the chlorinated hydrocarbon residues were performed using a gas chromatograph with a 63 Ni electron capture detector. The fishes had condition factor of more than 1 except Regalecus glesne. A higher concentration of the residues was observed during the dry season. The residue distribution pattern in muscle tissues of the fishes were: Regalecus glesne > Sardinella maderensis > Lutjanus goreensis. Regalecus glesne recorded the highest chlorinated hydrocarbon content: 6181.16 ng/g. Except for endrin and heptachlor, the estimated daily intakes of the organochlorines were within the acceptable daily intakes while the levels of residues in the fishes were within the permissible residue limits

Trace Metals Levels in Inorganic Fertilizers Commercially Available in Nigeria

Aims: To investigate the concentrations of arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), nickel (Ni), vanadium (V) and zinc (Zn) in commercially available inorganic fertilizers (calcium superphosphate and urea). Place and Duration of Study: Urea and superphosphate fertilizers were purchased from a local market in Uyo, Southern Nigeria. Methodology: A total of twenty seven fertilizer samples were randomly taken representing triplicate samples from three urea and six superphosphate original fertilizer bags. Each sample were digested and extracted using the ethylenediamine tetraacetic acid (EDTA) extraction technique. The elemental analysis was performed using an inductively coupled plasma atomic emission spectrophotometer (ICP-AES) (Optima 3000 – Perkin Elmer). Results: The analyses indicated the presence of trace metals in commercially available fertilizers sold in Nigeria. Cadmium was found in comparatively high concentrations. Zinc was found present in relatively high concentrations in both urea and phosphate fertilizer samples but As was found in low concentration. By comparison, the superphosphat

Analytical Relevance of Trace Metal Speciation in Environmental and Biophysicochemical Systems

This article presents a review of the analytical relevance of trace metal speciation analysis, which must be considered in environmental and biophysicochemical systems for reliable and efficient assessment and monitoring of trace metals. Examples are given of methodological approaches used for speciation analysis. An overview of speciation analysis in sediments, aquatic ecosystems and agrosystems is also presented

SPATIO-TEMPORAL VARIABILITY OF TRACE METALS IN ATMOSPHERIC FINE PARTICULATE MATTER FROM SELECTED INDUSTRIAL SITES IN OGUN STATE, NIGERIA

The spatial and temporal variations of fine particulate matter bound trace metals were investigated in three industrial estates namely Ota Industrial Estate (OTE), Ewekoro Community (EWC) and Agbara Industrial Estate (AGE) and one background (Covenant University Farm Ota) in Ogun State. The sampling period was six (6) months covering the wet and dry seasons. One hundred and fifty (150) samples were collected according to standard methods using environtech gravimetric sampler, after which fine particulate matter (PM2.5) mass concentration was computed gravimetrically. The total trace metals and chemical sequential extraction of twenty-two (22) trace metals (As, Cr, Pb, Ni, Cd, Mn, Ti, V, Ba, Fe, Al, Mo, Ca, Zn, Cu, Mg, Sr, Se, Ag, K, Na, and Sb) were further analysed by inductively coupled plasma mass spectrometry. Daily mean meteorological parameters for the study period were obtained from Nigerian Meteorological Agency. Cumulative lifetime cancer risk, air quality index and source apportionment of pollutants were also assessed. Spatio-temporal mass distribution of PM2.5 in the investigated sites indicated that the average annual PM2.5 mass concentrations were fifteen to twenty six (15-26) times and twelve to twenty two (12-22) times higher than the current annual World Health Organisation (WHO) and United States Environmental Protection Agency (US EPA) guideline of 10 and 12 μg/m3 respectively. OTE and CUF recorded the highest and lowest PM2.5 levels across seasons respectively while distinct seasonal variations trend showed dry > wet. Comparison of the annual average concentrations of Pb, As, Cd, Cr, Ni, Mn, V trace metals to the appropriate standard limit values reveals that out of these 7 trace metals, only V (0.199 - 0.862 μgm-3) was below the existing WHO limit of one (1 μg/m3).The meteorological parameter results revealed that relative humidity and rainfall significantly decreased the accumulation of fine particles whereas increased wind speed and temperature, showed a corresponding increase in the concentration of PM2.5. Speciation and bioavailability studies identified Cr, V, Cu, Cd and Cr, V Cu, Zn as the most labile metals present in OTE and EWC respectively. The sum of the cumulative lifetime cancer risk of inhalation exposure route was above EPA’s acceptable risk range of 1 × 10-6 to 1× 10-4 for both adults and children with the highest occurrence (9.53 × 10-2) in Ewekoro community. The absence of 0 to 50 gradations representing the good air quality index category was conspicuously highlighted. Scanning electron microscopy images of fine particles indicate that they are clustered into the following groups: soil dust mineral, soot aggregation, alumino silicate and fly ash particles. Hierarchical agglomerative clustering analysis of fine particles indicated major clustered groups while source identification using principle component analysis identified the origin of this source such as industrial processes, vehicle emissions, re-suspended and crustal dust, biomass burning, solid waste combustion and coal oil combustion. To improve on the present status of air quality, Nigerian Environmental Standards and Regulations Enforcement Agency (NESREA) should enforce environmental laws, ensure that all industries adopt standard emission control strategies and encourage the cultivation of green belts

Study of Surface Morphology, Elemental Composition and Sources of Airborne Fine Particulate Matter in Agbara Industrial Estate, Nigeria

Ambient atmospheric fine particle emission contribution to industrial pollution load is hard to quantify due to absence of air quality monitoring stations and difficulties in assessing suitable analytical instruments. Therefore, to keep abreast of air quality information, the use of physicochemical signatures to assess the sources of elements associated with fine particulate matter in Agabra Industrial Estate was explored with Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X-ray (EDX) and Principal Component Analysis (PCA). A greater proportion of Si and C were observed in the particles amongst other detected elements by EDX. Morphology results by SEM confirmed soot, alumino silicate and irregular shape mineral particles as the most common inhalable particles. Prominent among emission sources identified are industries, automobile exhaust, fugitive dust and solid waste combustion. The research suggests that adequate public awareness, industrial compliance, vehicle emission control, smooth operation of municipal solid waste incineration and government regulation will significantly reduce fine particulate pollution

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

Characterisation of Polychlorinated Biphenyls in Coastal Inland Seawater, Nigeria

The concentrations of polychlorinated biphenyls (PCBs) were determined in samples of surface seawater collected from five (5) different locations along the coastline of a tropical lagoon. The surface water samples were analysed using gas chromatography coupled with electron capture detector (GC-ECD) with fifteen (15) PCB congeners detected across the studied area. The chlorobiphenyls levels are in the order Ebute Ero > Oko Baba > Ijora > Lagos Island > Unilag lagoon front with levels 107.89, 53.15, 34.90, 27.78, and 2.15 mg/L, respectively. The enhanced average concentration of PCBs at the Ebute Ero site is due to the predominance of PCB-180 and PCB-185. A negative correlation was found between the total PCB concentration and the level of dissolved oxygen. Although, the results indicated fairly high levels of PCBs, the anthropogenic contributions from industrial releases and domestic activities may be largely associated with the detected concentrations of the di-, tetra-, penta-, hexa-, hepta-, and octa-chlorobiphenyl

Drinking Water Quality and Sanitation Issues: A Survey of a Semi-Urban Setting in Nigeria

An assessment on the drinking water quality from major source (borehole) and household in a semi-urban setting in Nigeria was carried out. Structured questionnaire was administered to randomly selected households in seven zones of the municipality to determine the common method of collection and transportation, storage, and sanitation practices. Water samples collected were subjected to laboratory analyses for physico-chemical and microbial properties. The result of the physico-chemical analysis when compared against the World Health Organization (WHO) and Standard Organization of Nigeria (SON) drinking water quality benchmark revealed that the water samples were within standards for consumable water except for the presence of feacal contamination. The result revealed that before water can be totally considered safe for drinking, further treatment is required at the household level due to fecal contamination, and water safety concerns are also highlighted. The result translates to the fact that compliance assessment with standards and impact assessment studies in determining the fate of pollutants is necessary at all level

Synthesis and Spectroscopic Study of Naphtholic and Phenolic Azo Dyes

Azo dyes are extremely important in variety of industries for variety of technical purposes. Hence, a series of naphtholic azo dyes 1-9 were synthesized via diazotization of substituted aniline derivatives followed by azo coupling with 2-naphthol. In similar manner, diazotization followed by azo coupling with phenol afforded phenolic azo dyes 10-17 in excellent yields. The chemical structures of all synthesized compounds were confirmed using analytical data and spectroscopic technique which include Uv-visible, IR, Mass spectra, 1H- and 13C-NMR