33 research outputs found
Heavy Metals and Polycyclic Aromatic Hydrocarbons in Soil from E-waste Dumpsites in Lagos and Ibadan, Nigeria
No full textBackground. Soil contamination from heavy metals and polycyclic aromatic hydrocarbons (PAHs) released during informal e-waste processing and disposal poses human and ecological health risks in Nigeria.
Objectives. This study assesses the levels of heavy metals and PAHs in soils of e-waste dumpsites in Lagos and Ibadan, Nigeria.
Methods. Composite soil samples were collected at depths of 0–15 cm, 15–30 cm and 30–45 cm from major e-waste dumpsites in Lagos and Ibadan and analyzed for lead (Pb), cadmium (Cd), copper (Cu), nickel (Ni), zinc (Zn), chromium (Cr) and PAHs to evaluate the potential contaminant contribution from e-waste activities. Control samples were collected at the Botanical Garden, University of Ibadan. Samples were analyzed for heavy metals after acid digestion using atomic absorption spectrophotometry, while PAHs were extracted using cold solvent extraction and quantified by gas chromatography-mass spectrometry. Blank determination and recovery studies were carried out for each metal. Contamination and ecological risks were assessed using soil contamination indices such as contamination factor, geo-accumulation and pollution load indices, and potential ecological risk index to categorize contaminant concentrations and associated impacts. Soil physico-chemical characteristics such as pH and total organic matter were also determined.
Results. Metals concentrations in the dumpsite soils ranged from 114–2,840 mg/kg and not detectable - 6.50 mg/kg for Pb and Cd, and 42.8–5,390 mg/kg, 27.5–3,420 mg/kg, 11.0–128 mg/kg and 94.0–325 mg/kg for Cu, Zn, Ni and Cr, respectively. Serious metals accumulation was observed at every e-waste dumpsite, as shown by the pollution load index. The potential ecological risk values were between 584 and 10,402 at all of the dumpsites, signifying very high ecological risk. The total PAHs ranged from 1,756–2,224 μg/kg at the 0–15 cm level, 1,664–2,152 μg/kg at 15–30 cm and 278 μg/kg in the top- and sub-soil of the control site.
Discussion. The total PAHs in the soil of e-waste dumpsites was significantly higher than in the control soil.
Conclusions. The results of this study indicate that indiscriminate dumping and open burning of e-waste are potential sources of PAH and toxic metal emissions, which can pose serious human health and ecological risks.
Competing interests. The authors declare no competing financial interests
Heavy Metals and Polycyclic Aromatic Hydrocarbons in Soil from E-waste Dumpsites in Lagos and Ibadan, Nigeria
No full textHeavy metal content of selected personal care products (PCPs) available in Ibadan, Nigeria and their toxic effects
No full textAbstractThere is a growing concern on heavy metals in consumer products due to their potential human health risks and environmental effects. In this study, the levels of zinc, cadmium, lead and nickel were assessed in 3 different classes of personal care products commonly used in Ibadan, Nigeria. Samples were analysed for heavy metals using Atomic Absorption Spectrophotometer (AAS) after acid digestion. Estimated daily intake (EDI) of the metals and Health Risk Index (HRI) were calculated to assess the human health risks associated with the use of these PCPs. The concentrations (mg/kg) of zinc ranged from 3.75 to 19.3, 1.88 to 112,000 and 19.8 to 217 respectively in creams, powders and eyeliners. Cadmium ranged from ND—0.50, ND—36.3 and ND—0.50mg/kg while lead ranged from ND—6.25, ND—468 and 3.73–27.5mg/kg and nickel ranged from ND—6.25, 0.13–107 and 2.75–22.7mg/kg respectively. There were high concentrations of Cd, Pb and Ni in some of the samples when compared with the available permissible limits in cosmetics (Cd: 0.3ppm, Pb: 10ppm and Ni: 0.6ppm while there is no permissible limit for Zn in cosmetics currently available). Prolonged use of PCPs may pose human health and environmental risks due to toxic metal loading through dermal contact and accumulation over a period of time. Hence, the need for necessary government agencies to regulate and enforce toxic metals in consumer products including cosmetics produced and imported into Nigeria to safeguard public health and the environment, which is the final sink
Lead and Cadmium Levels in Residential Soils of Lagos and Ibadan, Nigeria
No full textBackground. Lead and cadmium are components of paints sold in Nigeria. These heavy metals are associated with adverse neurological, cardiovascular and other human health effects.
Objectives. This study assesses the levels of lead and cadmium in topsoil of residential areas in Lagos and Ibadan potentially resulting from painting of buildings.
Methods. Samples were pre-treated prior to metal determination using atomic absorption spectrophotometry. Metal speciation was determined using modified Tessier sequential extraction. Soil characteristics were determined by standard methods. Soil contamination was assessed using contamination factor, geo-accumulation and pollution load indices. The United States Environmental Protection Agency integrated exposure uptake biokinetic (IEUBK) model was used to estimate and predict children's blood lead levels (BLL).
Results. Lead and cadmium concentrations in residential areas in Lagos and Ibadan ranged from 1.56–419 mg/kg and not detected–2.8 mg/kg, respectively. Metal contamination factor and pollution load index were highest at the Lagos low income settlement. Results of IEUBK modelling showed that the Lagos low income settlement had the highest probability density for children between 1–7 years of age with an estimated BLL of >10 μg/dL. This population made up less than 0.01% of those within this age range.
Conclusions. Lead and cadmium concentrations in soil around the residential buildings were higher than those in the control sample. Contamination factor and pollution load index showed significant contamination in average and low income settlements. These results suggested that there was accumulation of the metals in the soil, which can persist in the environment. This may pose serious health risks, especially to vulnerable groups such as children.
Competing Interests. The authors declare no competing financial interests
Lead and Cadmium Levels in Residential Soils of Lagos and Ibadan, Nigeria
No full textBackground. Lead and cadmium are components of paints sold in Nigeria. These heavy metals are associated with adverse neurological, cardiovascular and other human health effects.
Objectives. This study assesses the levels of lead and cadmium in topsoil of residential areas in Lagos and Ibadan potentially resulting from painting of buildings.
Methods. Samples were pre-treated prior to metal determination using atomic absorption spectrophotometry. Metal speciation was determined using modified Tessier sequential extraction. Soil characteristics were determined by standard methods. Soil contamination was assessed using contamination factor, geo-accumulation and pollution load indices. The United States Environmental Protection Agency integrated exposure uptake biokinetic (IEUBK) model was used to estimate and predict children's blood lead levels (BLL).
Results. Lead and cadmium concentrations in residential areas in Lagos and Ibadan ranged from 1.56–419 mg/kg and not detected–2.8 mg/kg, respectively. Metal contamination factor and pollution load index were highest at the Lagos low income settlement. Results of IEUBK modelling showed that the Lagos low income settlement had the highest probability density for children between 1–7 years of age with an estimated BLL of >10 μg/dL. This population made up less than 0.01% of those within this age range.
Conclusions. Lead and cadmium concentrations in soil around the residential buildings were higher than those in the control sample. Contamination factor and pollution load index showed significant contamination in average and low income settlements. These results suggested that there was accumulation of the metals in the soil, which can persist in the environment. This may pose serious health risks, especially to vulnerable groups such as children.
Competing Interests. The authors declare no competing financial interests.</jats:p
Trace Metals Charaterisation of Soils in the Vicinity of a Major Active Dumpsite in Lagos: An Integrative Multivariate Indices Approach
No full textOxygenated Volatile Organic Compounds (Anti-freezing Agents) in Decorative Water-based Paints Marketed in Nigeria
No full textBackground. Consumer products such as paints are a potentially significant source of volatile organic compounds (VOCs) and oxygenated VOCs. Paints for construction and household use have been rapidly changing from oil-based to water-based paints and are one of the commonly identified sources of oxygenated VOCs in indoor environments.
Objectives. Four different anti-freezing agents were identified and analyzed in 174 waterbased paint samples, purchased from popular paint markets in two metropolitan cities in Nigeria, Lagos and Ibadan.
Methods. Paint samples were solvent extracted using acetonitrile and milli-Q water. Antifreezing agents in the extracts were identified and quantified using gas chromatography (GC)-mass spectrometry and a GC-flame ionization detector, respectively.
Discussion. Four different anti-freezing agents were identified in the samples, ethylene glycol, diethylene glycol, triethylene glycol and propylene glycol. Their levels ranged from 1,000-1,980 ppm, diethylene glycol; 1,000–3,900 ppm, triethylene glycol; 1,090–2,510 ppm, propylene glycol and 1,350–2,710 ppm, ethylene glycol. Levels of anti-freezing agents in all of the paint samples were above the permissible limits of the European Union for VOCs in paints of 500 ppm. Results of multivariate statistical analyses clearly showed that triethylene glycol was the most commonly used anti-freezing agent in paints despite its numerous harmful health effects.
Conclusions. We concluded that water-based paints marketed in Nigeria contain high concentrations of anti-freezing agents, which have harmful environmental and human health effects, especially to sensitive individuals such as children.
Competing Interests. The authors declare no competing financial interests.</jats:p
Vulnerability assessment of groundwater pollution in the vicinity of an active dumpsite (Olusosun), Lagos, Nigeria
No full textThe deleterious impacts of dumpsite activities and the associated risk on both the
environment and human is consequential, hence this study assessed
groundwater vulnerability to pollution from dumpsite using a modified DRASTIC
model. Six hydrogeological factors: D- Depth to water, R- Net Recharge, AAquifer
media, L- Distance of well to dumpsite, T- Topography, and C- Clay
content were used in the modification (DRALTC) based on peculiarity of the
study area. Cluster analysis of groundwater data and Water Quality Index (WQI)
were also evaluated. The groundwater vulnerability index was characterized by
two zones; forty five percent (45%) moderate and fifty five percent (55%) high
zones. The dendogram showed three clusters of chemical dissimilarities. The
WQI showed values between 61.8 and 205, indicating good, poor and very poor
class of water. The analysis of the groundwater samples showed nitrate
concentration ranging from 7.60 to 35.6 mg/L and from 8.56 to 32.4 mg/L in dry
and rainy seasons, respectively. The DRALTC model was validated using nitrate
concentration. Though, there appeared relative groundwater protection from
contamination, there is still need for measures to mitigate further contamination
and associated risk in the moderate vulnerability zones. DRALTC model is proved
a good tool in groundwater management
Oxygenated Volatile Organic Compounds (Anti-freezing Agents) in Decorative Water-based Paints Marketed in Nigeria
No full textBackground. Consumer products such as paints are a potentially significant source of volatile organic compounds (VOCs) and oxygenated VOCs. Paints for construction and household use have been rapidly changing from oil-based to water-based paints and are one of the commonly identified sources of oxygenated VOCs in indoor environments.
Objectives. Four different anti-freezing agents were identified and analyzed in 174 waterbased paint samples, purchased from popular paint markets in two metropolitan cities in Nigeria, Lagos and Ibadan.
Methods. Paint samples were solvent extracted using acetonitrile and milli-Q water. Antifreezing agents in the extracts were identified and quantified using gas chromatography (GC)-mass spectrometry and a GC-flame ionization detector, respectively.
Discussion. Four different anti-freezing agents were identified in the samples, ethylene glycol, diethylene glycol, triethylene glycol and propylene glycol. Their levels ranged from 1,000-1,980 ppm, diethylene glycol; 1,000–3,900 ppm, triethylene glycol; 1,090–2,510 ppm, propylene glycol and 1,350–2,710 ppm, ethylene glycol. Levels of anti-freezing agents in all of the paint samples were above the permissible limits of the European Union for VOCs in paints of 500 ppm. Results of multivariate statistical analyses clearly showed that triethylene glycol was the most commonly used anti-freezing agent in paints despite its numerous harmful health effects.
Conclusions. We concluded that water-based paints marketed in Nigeria contain high concentrations of anti-freezing agents, which have harmful environmental and human health effects, especially to sensitive individuals such as children.
Competing Interests. The authors declare no competing financial interests
Fintech Rulemaking: Evidence from Middle East and Africa
No full textIn recent times, there has been a flurry of fintech policymaking across the Middle East and Africa (MEA) region. This chapter studies fintech rulemaking processes across the MEA region. Earlier research has described responses to fintech as (a) Wait and See, (b) Test and Learn, (c) Innovation Facilitators (includes regulatory sandboxes, innovation hubs, and accelerators), and (d) Regulatory Laws and Reform. This chapter is about the regulatory reforms with theoretical foundation in policy diffusion and administrative process. The author extends an emerging scholarship on administrative process theory of central banking. The author asserts fintech policies began with initial guidance from multilateral development banks (World Bank, IMF, UNECA, UNCDF), global standard-setting bodies (Basel Committee on Banking Supervision, Financial Stability Board), regional organization (Arab Monetary Fund), and collaborative network (Alliance for Financial Inclusion). Over time, MEA nations developed their fintech-specific regulations.The author used a self-gathered private dataset of fintech rulemaking processes across the MEA region, the World Bank Global Fintech-enabling regulations database, and the World Bank’s Global Indicators of Regulatory Governance (GRG). From the data analysis, the author’s findings led to three conceptual frameworks: (i) solicitation, (ii) engagement, and (iii) custodianship.Solicitation refers to when financial regulators (central banks, securities regulators) ask for input from the public. Engagement could take any of these form cooperation and collaboration. It refers to activities that keep regulators and the public to interact as well as help improve fintech regulatory decision-making. Lastly, custodianship explores the prerogative role held by financial regulators to guard, protect, and maintain financial inclusion, stability, integrity, and protection (I-SIP) of the financial system.https://link.springer.com/rwe/10.1007/978-981-96-6143-5_1
