Reliability of stored river water as an alternative for consumption in Ekpoma, Nigeria: a human health risk assessment

With looming global water-related issues, the monitoring of water quality for household and industrial consumption has become more pertinent. Rivers in nearby towns serve as primary water sources for Ekpoma town. 123 samples of stored river water were collected from 41 sampling locations and physical properties - pH, electrical conductivity (EC), salinity, temperature, and total dissolved solids (TDS) - were measured in situ using the Hanna edge® Multiparameter EC/TDS/Salinity Meter-HI2030. Atomic absorption spectrophotometry (AAS) was used to detect and measure the concentration of potentially toxic metals (PTMs): Al, Cr, Cu, Fe, Mn, Ni, Pb, and Zn. The measured concentrations were compared to the WHO, US EPA, and NSDWQ regulatory standards, and a spatiotemporal health risk analysis was performed using HERisk software. Twenty-five percent of the tested samples contained PTM concentrations within the allowable regulatory limits. Spatiotemporal health risk analysis showed that 98.8% of the cumulative carcinogenic risks (CRcum) were entirely from Pb contamination via oral ingestion. PTM concentrations in the samples suggest the degradation of river water quality due to agricultural activities, crude oil exploration activities, and soil composition in the region. Best management practices (BMPs) and treatment processes for the removal of detected contaminants are recommended to improve water quality

Review

Previous surgical procedures devised for intractable pain are the excision of painful area of the skin, peripheral neurotomy, intraspinal or intracranial posterior rhizotomies, anterolateral spinal cordotomy, spinothalamic tractotomy at medulla and mesencephalon for the pain of organic origin, and the prefrontal lobotomy for psychogenic pain. Unfortunately, these procedures are followed either by disturbance of physiologic sensory function or by changes of affect and personality. Partial gasserian gangliolysis successfully alleviated the trigeminal neuralgia without significant sensory disturbance of the face. Recent advances in stereotaxic technique has enabled us to attack the thalamus and other deep subcortical centers. This new method, together with recent neuroanatomico-physiological progress in regard to pain tract through intralaminar nuclear complex, resulted in discovery of thalamotomy destroying the nucleus centrum medianum with or without adjacent intralaminar nuclei, which eliminates the organic pain without any detectable sensory deficit. Anterior cingulectomy or cingulumotomy has developed to alleviate the psychogenic pain without psychological changes. These are the ideal pain-relieving procedures. A new method of percutaneous cervical cordotomy can be safely used for the debilitated patients with terminal malignant diseases

Data on quantification of PAHs and elemental content in dry Camellia sinensis and herbal tea

Here we present data on potentially toxic metals and polycyclic aromatic hydrocarbons (PAHs) in commercially sold tea brands in Nigeria. The article provides data on the sequential extraction and the pseudo-total concentrations of eight metals (Cd, Cr, Cu, Mn, Ni, Pb, V and Zn) and polycyclic aromatic hydrocarbons (PAHs) in dry Camellia sinensis and herbal tea. The three-step Community Bureau of Reference (BCR) method and acid digestion with aqua regia were adopted for sequential and total metal extractions, respectively. The extraction of branded tea samples for PAHs analysis has been described in “Concentrations, sources and risk characterisation of polycyclic aromatic hydrocarbons (PAHs) in green, herbal and black tea products in Nigeria” [1] and “Polycyclic Aromatic Hydrocarbons (PAHs) Occurrence and Toxicity in C. sinensis and Herbal Tea” [2]. Elemental and PAHs analyses of extracts were determined by Microwave Plasma Atomic Emission Spectroscopy (Agilent MP-AES 4100) and Agilent gas chromatograph 7890A coupled with flame ionization detector (FID), respectively

Coastal Vulnerability Assessment: A Case Study of the Nigerian Coastline

Coastal regions are one of the essential spots on the earth as they are hosts to various important ecosystems, natural resources and the increasing population. Based on their proximity to the seas, they are mainly affected by sea-level rise, which is one of the adverse effects of climate change. This has resulted in associated hazards, such as beach erosion, flooding, coastal inundation, habitat destruction, saltwater intrusion into ground water aquifers and ecosystem imbalance. This study quantifies and classifies the vulnerability of the Nigerian coastline to these threats using the analytical hierarchical approach. This involved calculating the coastal vulnerability index (CVI) employing physical and geomorphological variables, and socioeconomic indicators that characterized the coastline vulnerability. The Nigerian coast was divided into seventeen (17) segments based on geomorphic units. The different vulnerability variables were assigned ranks ranging from 1 to 5, with 5 indicating the highest and 1 indicating the lowest vulnerabilities. The geomorphological and physical parameters include coastal slope, bathymetry, geomorphology, wave height, mean tidal range, shoreline change rate and relative sea-level rise, while the socioeconomic parameters include population, cultural heritage, land use/land cover and road network. The calculated CVI values (Saaty method) ranged from 11.25 to 41.66 with a median value of 23.60. Based on Gornitz approach, the calculated measures ranged between 3.51–4.77 and 3.08–5.00 for PVI and SoVI, respectively. However, the aggregated coastal vulnerability index computed using this approach ranged from 3.29 to 4.70. The results obtained from both approaches showed that 59–65% of the entire Nigerian coastline is under moderate to high vulnerability to sea-level rise. Data indicted how the coastal populations are highly vulnerable to both physical–geomorphological and socioeconomic stressors. Coastal vulnerability maps, highlighting the physical–geomorphological and socioeconomic vulnerability status of Nigerian coastline were also generated. The information from this study will assist coastal planners in identifying vulnerable segments in the study area and subsequently aid decisions that would mitigate the predicted impacts in the region

Coastal Vulnerability Assessment: A Case Study of the Nigerian Coastline

Coastal regions are one of the essential spots on the earth as they are hosts to various important ecosystems, natural resources and the increasing population. Based on their proximity to the seas, they are mainly affected by sea-level rise, which is one of the adverse effects of climate change. This has resulted in associated hazards, such as beach erosion, flooding, coastal inundation, habitat destruction, saltwater intrusion into ground water aquifers and ecosystem imbalance. This study quantifies and classifies the vulnerability of the Nigerian coastline to these threats using the analytical hierarchical approach. This involved calculating the coastal vulnerability index (CVI) employing physical and geomorphological variables, and socioeconomic indicators that characterized the coastline vulnerability. The Nigerian coast was divided into seventeen (17) segments based on geomorphic units. The different vulnerability variables were assigned ranks ranging from 1 to 5, with 5 indicating the highest and 1 indicating the lowest vulnerabilities. The geomorphological and physical parameters include coastal slope, bathymetry, geomorphology, wave height, mean tidal range, shoreline change rate and relative sea-level rise, while the socioeconomic parameters include population, cultural heritage, land use/land cover and road network. The calculated CVI values (Saaty method) ranged from 11.25 to 41.66 with a median value of 23.60. Based on Gornitz approach, the calculated measures ranged between 3.51–4.77 and 3.08–5.00 for PVI and SoVI, respectively. However, the aggregated coastal vulnerability index computed using this approach ranged from 3.29 to 4.70. The results obtained from both approaches showed that 59–65% of the entire Nigerian coastline is under moderate to high vulnerability to sea-level rise. Data indicted how the coastal populations are highly vulnerable to both physical–geomorphological and socioeconomic stressors. Coastal vulnerability maps, highlighting the physical–geomorphological and socioeconomic vulnerability status of Nigerian coastline were also generated. The information from this study will assist coastal planners in identifying vulnerable segments in the study area and subsequently aid decisions that would mitigate the predicted impacts in the region

Metagenomics: an emerging tool for the chemistry of environmental remediation

Metagenomics is the study of genetic information, including the sequences and genomes of microorganisms present in an environment. Since 1998, the full-scale application of this technique to environmental chemistry has brought significant advances in the characterization of the nature and chemical composition/distribution of contaminants present in environmental matrices of contaminated and/or remediated sites. This has been critical in the selection of microorganisms and has contributed significantly to the success of this biological treatment over the years. Metagenomics has gone through different phases of development, which ranges from initial sequencing strategies to next-generation sequencing (NGS), which is a recently developed technology to obtain more robust deoxyribonucleic acid (DNA) profile of microorganisms devoid of chimeric sequences which reduces the quality of metagenomic data. Therefore, the objective of this review is to evaluate the applications of metagenomics in the understanding of environmental dynamics of chemical contaminants during remediation studies. Also, this review presents the relationship between biological characteristics of microorganisms and chemical properties of chemical compounds, which forms the basis of bioremediation and could be useful in developing predictive models that could enhance remediation efficiency. In conclusion, metagenomic techniques have improved the characterisation of chemical contaminants in the environment and provides a correlation for useful prediction of the type of contaminant expected in various environmental matrices

Chemical Speciation and Characterization of Trace Metals in Dry Camellia sinensis and Herbal Tea Marketed in Nigeria

Background. Trace metals from anthropogenic activities have been found to occur in tea brands and pose potential human health risks to consumers. Objectives. The present study assessed the concentrations of trace metals in green, black and herbal tea brands using a modified Community Bureau of Reference sequential extraction method. Methods. Fifteen (15) Camellia sinensis and eight (8) herbal tea samples commonly consumed in Nigeria were collected and analyzed for trace metals. The concentrations of cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), vanadium (V), and zinc (Zn) in extract fractions were analyzed using microwave plasma atomic emission spectroscopy (MP-AES). Results. Trace metals were detected in all of the samples investigated. The concentrations of trace metals in 4 stages (soluble/exchangeable/carbonates bound fraction, reducible fraction, oxidizable fraction, residual fraction) of sequential and pseudo-total metal extraction procedures are presented. The concentrations of Cd, Cr, Cu, Mn, Ni, Pb, V, and Zn in the exchangeable/carbonate bound fraction for green tea ranged between 0.27–1.47, ND-0.33, ND-0.44, 7.05–33.04, 0.23–0.69, ND-0.51, ND-0.16 and 0.18–1.99 mg/kg, ND-0.73, 0.15–0.36, 0.36–0.59, 1.38–30.07, 0.15–0.54, 0.05–0.76, 0.15–0.34 and 0.27–0.77 mg/kg and 0.54–0.64, 0.25–0.41, 0.35–0.47, 18.72–23.98, 0.30–0.55, 0.15–0.21, 0.15–0.23 and 0.30–0.48 mg/kg for hebal tea, respectively. Conclusion. The metal content in the investigated tea indicated low to enhanced concentrations. Locally produced black teas recorded relatively low trace metal contents compared to the green and herbal tea samples. The most bioavailable trace metal was Mn, while Zn was most preferably bound to the residual fraction. Cadmium, Cr, Cu, Ni, Pb, and V were distributed at varied concentrations among other extractable phases. Daily consumption of the investigated tea products may expose consumers to potentially toxic metals as well as essential elements. Competing interests. The authors declare no competing financial interests

Chemical Speciation and Characterization of Trace Metals in Dry Camellia sinensis and Herbal Tea Marketed in Nigeria

Background. Trace metals from anthropogenic activities have been found to occur in tea brands and pose potential human health risks to consumers. Objectives. The present study assessed the concentrations of trace metals in green, black and herbal tea brands using a modified Community Bureau of Reference sequential extraction method. Methods. Fifteen (15) Camellia sinensis and eight (8) herbal tea samples commonly consumed in Nigeria were collected and analyzed for trace metals. The concentrations of cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), vanadium (V), and zinc (Zn) in extract fractions were analyzed using microwave plasma atomic emission spectroscopy (MP-AES). Results. Trace metals were detected in all of the samples investigated. The concentrations of trace metals in 4 stages (soluble/exchangeable/carbonates bound fraction, reducible fraction, oxidizable fraction, residual fraction) of sequential and pseudo-total metal extraction procedures are presented. The concentrations of Cd, Cr, Cu, Mn, Ni, Pb, V, and Zn in the exchangeable/carbonate bound fraction for green tea ranged between 0.27–1.47, ND-0.33, ND-0.44, 7.05–33.04, 0.23–0.69, ND-0.51, ND-0.16 and 0.18–1.99 mg/kg, ND-0.73, 0.15–0.36, 0.36–0.59, 1.38–30.07, 0.15–0.54, 0.05–0.76, 0.15–0.34 and 0.27–0.77 mg/kg and 0.54–0.64, 0.25–0.41, 0.35–0.47, 18.72–23.98, 0.30–0.55, 0.15–0.21, 0.15–0.23 and 0.30–0.48 mg/kg for hebal tea, respectively. Conclusion. The metal content in the investigated tea indicated low to enhanced concentrations. Locally produced black teas recorded relatively low trace metal contents compared to the green and herbal tea samples. The most bioavailable trace metal was Mn, while Zn was most preferably bound to the residual fraction. Cadmium, Cr, Cu, Ni, Pb, and V were distributed at varied concentrations among other extractable phases. Daily consumption of the investigated tea products may expose consumers to potentially toxic metals as well as essential elements. Competing interests. The authors declare no competing financial interests