Spatio-temporal distribution, source apportionment, ecological and human health risks assessment of polycyclic aromatic hydrocarbons in Sombreiro River Estuary, Niger Delta, Nigeria.

The spatio-temporal distribution, source apportionment, and risks of polycyclic aromatic hydrocarbon (PAHs) were investigated in the Sombreiro River Estuary, Niger Delta, Nigeria. Water, sediment and oysters were obtained from the estuary and analyzed for 16 priority PAHs using gas chromatograph coupled with mass selective detector after extraction. The levels of the ∑16-PAHs in the water, sediment and oyster ranged from 25-10079 µg/L, 495-12811 µg/kg and 489-10823 µg/kg respectively for all locations and seasons.

Human exposure to endocrine-disrupting organochlorine and organophosphate pesticides in locally produced and imported honey in Nigeria.

The practice of exposing honeybees to pesticides by bee-keepers or via agricultural crops, is one of the ways in which honey becomes contaminated with pesticides. Though honey has many health advantages, however, human exposure to pesticides via consumption of honey has generated public health concerns due to their endocrine-disruptive abilities. Thus, this study evaluated human exposure to endocrine-disrupting pesticides in honey from Nigeria to establish the safety of honey consumed in Nigeria.

Spatial characteristics, sources and exposure risk of polychlorinated biphenyls in dusts and soils from an urban environment in the Niger Delta of Nigeria.

Chlorinated organic compounds, such as polychlorinated biphenyls (PCBs), are a threat to both humans and the environment because of their toxicity, persistence, and capacity for long-range atmospheric transport. The concentrations of 28 PCB congeners, including 12 dioxin-like and seven indicator PCBs, were investigated in soils, and indoor and outdoor dusts from Port Harcourt city, Nigeria, in order to evaluate the characteristic distribution patterns in these media, their sources, and possible risk. The PCB concentrations varied from 4.

Spatial distribution of polycyclic aromatic hydrocarbons in dust and soils from informal trade sites in southern Nigeria: Implications for risk and source analysis.

Polycyclic aromatic hydrocarbons (PAHs) are a group of semi-volatile and persistent organic compounds considered priority pollutants because of their pervasive nature and high toxicity to the ecosystem and humans. Therefore, this study aimed to evaluate the PAH concentrations in dust and soils around informal trade sites (ITS) in Nigeria to determine the level of risk, sources, and significance of these activities to the PAH load of the environment. The 16 US EPA PAHs in dust and soils from ITS were determined by gas chromatography-mass spectrometry (GC-MS).

Polychlorinated biphenyls and polychlorinated dibenzo-p-dioxins and furans in imported canned fish in Nigeria and risk assessment.

Concentrations of polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-dioxins and furans (PCDD/Fs) were measured in imported canned fish such as mackerel, sardine and tuna to evaluate the risk relating to human consumption of these products. Gas chromatography-mass spectrometry (GC/MS) was used to evaluate the concentrations of PCBs and PCDD/Fs in the samples. The 28 PCB concentrations in the canned mackerel, tuna and sardine ranged from 0.

Human exposure to organochlorine pesticides in vegetables from major cities in south-south Nigeria.

Contamination of vegetables with organochlorine pesticides (OCPs) during cultivation could affect their nutritional value and also results in adverse health effects to consumers. Thus, this study evaluates human exposure to OCPs in vegetables from major cities in south-south Nigeria. A total of eighty vegetables consisting of Vernonia amygdalina, Telfairia occidentalis, Desmodium intortum cv and Talinum triangulare obtained from four major cities (Warri, Benin, Yenagoa and Port-Harcourt) in south-south Nigeria were analysed for OCPs using a gas chromatograph coupled with a mass selective detector.

Occurrence and spatial characteristics of polychlorinated biphenyls (PCBs) in sediments from rivers in the western Niger delta of Nigeria impacted by urban and industrial activities.

The characteristic concentrations of 28 PCB congeners, their spatial distributions, sources, and associated risks to the ecosystem were investigated in sediments of some rivers around a glass industry and power generating plant in the Niger Delta of Nigeria. Gas chromatography-mass spectrometry (GC-MS) was applied for the identification and quantification of PCBs in sediments from these rivers. The Ʃ28 PCB concentrations (dry weight) in sediments ranged from 1520 to 3540 ng g for the Afiesere River, 976-5670 ng g for the Edor River, and from 1440 to 6340 ng g for the Okpare River.

Concentrations, sources, and exposure risk of polychlorinated biphenyls in soil profiles of the floodplain of the lower reaches of the River Niger, Nigeria.

The concentrations of 28 polychlorinated biphenyls (PCBs) were determined in soils collected at three depths from thirteen different sites along the floodplain of the lower reaches of the River Niger (LRRN) in Nigeria. The aim of the study was to provide data on the levels of contamination, sources of the contaminants, and risks to the ecosystem and humans. Soil samples were Soxhlet extracted with a solvent mixture of dichloromethane (DCM)/n-hexane and cleaned up on a column packed with Florisil and silica gel.

Distribution, sources and exposure risk of polycyclic aromatic hydrocarbons in soils, and indoor and outdoor dust from Port Harcourt city, Nigeria.

In this study, we evaluated the concentrations, composition, sources, and potential risks of polycyclic aromatic hydrocarbons (PAHs) in soils, and indoor and outdoor dust from Port Harcourt city in Nigeria. Gas chromatography-mass spectrometry (GC-MS) was used for the detection and quantification of PAH species in the samples. The concentrations of the US EPA 16 PAHs plus 2-methyl-naphthalene (∑17 PAHs) in soils, and indoor and outdoor dust from Port Harcourt city ranged from 240 to 38 400, 276 to 9130 and 44 to 13 200 μg kg (dry weight, d.

Impact of Land-Use Types on the Distribution and Exposure Risk of Polycyclic Aromatic Hydrocarbons in Dusts from Benin City, Nigeria.

The concentrations of the sixteen United States Environmental Protection Agency polycyclic aromatic hydrocarbons (PAHs) were determined in dusts from different land-use types in Benin City by means of gas chromatography-mass spectrometry. The results obtained were used to assess the ecological and human health risk and to determine the source apportionment. The Ʃ16 PAH concentrations in dusts from Benin City ranged from 230 to 2300 µg kg for industrial areas, 211-1330 µg kg for commercial areas, 153-1170 µg kg for residential areas, and from 216 to 1970 µg kg for school playgrounds/parks.

Polycyclic aromatic hydrocarbons (PAHs) in leafy vegetables consumed in southern Nigeria: concentration, risk assessment and source apportionment.

Four commonly consumed leafy vegetables, obtained from four major cities in southern Nigeria, were analysed for their polycyclic hydrocarbon (PAH) content using gas chromatography coupled with mass spectrometry (GC-MS). The estimated daily intake (EDI), margin of exposure (MOE), hazard index (HI) and total cancer risk (TCR); principal component analysis (PCA) and diagnostic ratios (DRs) were respectively used for risk evaluation and source identification of the detected PAHs. The results showed that the mean concentration (µg kg) of ∑16 PAHs in the vegetables ranged from 532 to 2261.

Polycyclic aromatic hydrocarbons (PAHs) in surficial sediments from selected rivers in the western Niger Delta of Nigeria: Spatial distribution, sources, and ecological and human health risks.

This study assessed the concentrations, sources, and risks of polycyclic aromatic hydrocarbons (PAHs) in sediments from the Rivers Niger, Ase and Forcados in the western Niger Delta. The concentrations of PAHs (in μg kg dry weight), as determined by gas chromatography-mass spectrometry, in sediments from these rivers varied from 2400 to 19,000, 2930 to 16,100, and from 1620 to 19,800 for the Niger, Ase and Forcados Rivers respectively. High molecular weight (HMW) PAHs were the most prevalent compounds present in these sediments.

Distribution and Sources of n-Alkanes and Polycyclic Aromatic Hydrocarbons in Sediments Around Oil Production Facilities in the Escravos River Basin, Niger Delta, Nigeria.

This study provides data on the characteristic levels, spatial patterns, sources, and risk of n-alkanes (AHs) [octane, n-C, to tetracontane, n-C] and polycyclic aromatic hydrocarbons (PAHs) in surficial sediments from the Escravos River Basin (ERB), Nigeria. The n-alkane and PAH concentrations in sediments were quantified by chromatographic methods. The concentrations of AHs and PAHs in the ERB sediments varied from 95 to 3430 µg g and from 0.

Spatial characteristics, sources, and ecological and human health risks of polychlorinated biphenyls in sediments from some river systems in the Niger Delta, Nigeria.

Polychlorinated biphenyls (PCBs) were quantified in sediments from the lower reaches of the Niger, Ase and Forcados Rivers in Nigeria with the aim of elucidating the sources, spatial characteristics and likely ecological and human health risks relating to exposure to PCBs in the sediments. A total of 28 PCB congeners, including 7 indicator PCBs and 12 dioxin-like PCBs, were identified and quantified after Soxhlet extraction with acetone/n-hexane/dichloromethane by gas chromatography-mass spectrometry. The Σ28 PCB concentrations in sediments from the Niger, Ase and Forcados Rivers ranged from 13.

Spatial characteristics and risk assessment of polychlorinated biphenyls in surficial sediments around crude oil production facilities in the Escravos River Basin, Niger Delta, Nigeria.

In this study, the concentrations of 28 polychlorinated biphenyl (PCB) congeners, including 12 dioxin-like PCBs and 7 indicator PCBs, were determined in sediments around oil production facilities in the Escravos River Basin of the Niger Delta in Nigeria. The aim was to describe the spatial patterns, sources, and ecosystem risks associated with exposure to PCBs in sediments of this river basin. Gas chromatography-mass spectrometry (GC-MS) was used to determine the concentrations of PCBs in the sediments.

Occurrence, sources and ecological and human health risks of polycyclic aromatic hydrocarbons in soils from some functional areas of the Nigerian megacity, Lagos.

The study investigated the levels of the USEPA 16 PAHs in soils collected from selected functional areas (cemetery, commercial, industrial and residential areas) of the Nigerian megacity, Lagos. The soil samples were subjected to ultrasonic-assisted extraction in a 1:1 (v/v) mixture of dichloromethane/hexane, and the PAHs in the resulting extracts were determined by gas chromatography-mass spectrometry. The Σ16 PAHs in soils of these functional areas varied between 890-4675, 485-4513, 111-15,577 and 509-2047 μg kg for cemetery, industrial, commercial and residential areas, respectively.

Polychlorinated biphenyls in canned sardines in Nigeria and health risk assessment.

The concentrations and potential human health risks through dietary ingestion of PCBs in canned sardines collected from the Nigerian market were determined. The results shows that the total PCBs concentrations varied from Hexa-PCBs > Tetra-PCBs > Di-PCB > Deca-PCB > Tri-PCBs > Hepta-PCBs > Octa-PCB.

Risk of human exposure to metals in some household hygienic products in Nigeria.

This study presents data on the levels and risk of human exposure to Cd, Pb, Cr, Ni, Cu, Co, Mn, Zn and Fe in some popular brands of household hygienic products (HHPs) available in Nigeria. The HHPs were digested with a mixture of HNO, HCl and HClO in a ratio of 1:3:1 and the concentrations of the selected metals were quantified by atomic absorption spectrophotometry. The metal concentrations (in μg g) in these products ranged from 0.

Characterization of metals in indoor dusts from electronic workshops, cybercafés and offices in southern Nigeria: Implications for on-site human exposure.

The levels of Cd, Pb, Cr, Ni, Cu, Co, Ba, Mn, Zn, Al and Fe were evaluated in indoor dusts from electronic workshops, cybercafés and offices in southern Nigeria. The study was aimed at providing information on the distribution patterns, and the associated risks that may arise from exposure of humans to these metals in indoor dusts from the three work environments. The dust samples were digested with aqua-regia and analyzed for the metal concentrations by inductively coupled plasma-atomic emission spectrometry (ICP-AES).

Concentrations and exposure risks of some metals in facial cosmetics in Nigeria.

The concentrations of nine metals (Cd, Pb, Ni, Cr, Co, Cu, Fe, Mn and Zn) were determined in lip sticks, lip glosses, lip balms, eye pencils, eyeliners, eye shadows, blushes, mascaras and face powders. The study was aimed at providing information on the risk associated with human exposure to metals in these facial cosmetic products. The concentrations of metals in the samples were measured by atomic absorption spectrometry after digestion with a mixture of nitric acid, hydrochloric acid and hydrogen peroxide.

Lagdo Dam Flood Disaster of 2012: An Assessment of the Concentrations, Sources, and Risks of PAHs in Floodplain Soils of the Lower Reaches of River Niger, Nigeria.

The concentrations of the USEPA 16 priority polycyclic aromatic hydrocarbons (PAHs) in soils of the floodplain of the lower reaches of River Niger, Nigeria, were investigated following the Lagdo Dam flood disaster of 2012. The aim was to provide information on the extent of contamination, sources, and risks of PAHs in these soils. The concentrations of Σ16 PAHs in the floodplain soils ranged from 812 to 10,700 μg kg.

Concentrations and profiles of polycyclic aromatic hydrocarbons in some popular fish species in Nigeria.

The concentrations and profiles of polycyclic aromatic hydrocarbons (PAHs) in 10 popular fish species in the Nigerian market were determined with a view to providing information on the health hazards associated with the consumption of these fish species. The concentrations of PAHs were measured by gas chromatography-mass spectrometry after extraction by ultrasonication with acetone-dichloromethane and clean up. The concentration ranges of the Σ16 PAHs were 20 to 39.

Safety evaluation of metal exposure from commonly used moisturizing and skin-lightening creams in Nigeria.

The concentrations of ten metals (Cd, Pb, Ni, Cr, Cu, Co, Fe, Mn, Zn and Al) were measured in some commonly used moisturizing and skin-lightening creams in Nigeria with a view to providing information on the risk of exposure to metals from the use of these products. The metal concentrations in these products were measured by atomic absorption spectrometry after acid digestion of the samples. The measured concentrations of metals in the skin moisturizing creams ranged from <0.

Polycyclic aromatic hydrocarbon concentrations in commercially available infant formulae in Nigeria: estimation of dietary intakes and risk assessment.

The concentrations and profiles of polycyclic aromatic hydrocarbons (PAHs) in commercially available infant formulae and follow-up formulae in Nigeria were determined with a view to providing information on the health risks to children from the consumption of these infant foods. The concentrations of PAHs were measured by means of gas chromatography-mass spectrometry (GC-MS) after extraction by ultrasonication with acetone/dichloromethane and clean-up. The concentrations of the Σ16 PAHs in these infant formulae ranged from 0.