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1.
J Hazard Mater ; 421: 126709, 2022 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-34315021

RESUMEN

Nanoscale zero-valent iron nanoparticles (nZVI) have been used for groundwater remediation and wastewater treatment due to their high reactivity, high adsorption capacity and nontoxicity. However, side reactions generally occur in tandem with the target contaminants removal process, resulting in poor electron selectivity (ES) of nZVI, and subsequently restricting its commercial application. Major efforts to increase ES of nZVI have been made in recent years. This review's objective is to provide a progress report on the significant developments in nZVI's ES during the past decade. Firstly, the definition of ES and its quantification approaches were documented, and the intrinsic (i.e. particle size, crystallinity, and surface area) and extrinsic factors (i.e. solutions pH, target contaminant concentration, and presence of co-contaminants) affecting the ES of nZVI were reported. The latest techniques for increasing ES were summarized in detail, with reference made to sulfidation, magnetization, carbon loading and other features. Then the mechanisms of those strategies for ES enhancement were described. Finally, some constructive suggestions on future research directions concerning nZVI's ES in the future were proposed.


Asunto(s)
Restauración y Remediación Ambiental , Agua Subterránea , Contaminantes Químicos del Agua , Purificación del Agua , Electrones , Hierro , Contaminantes Químicos del Agua/análisis
2.
J Hazard Mater ; 421: 126708, 2022 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-34352521

RESUMEN

The level and distribution of 16 USEPA Polycyclic aromatic hydrocarbon (PAHs) in aquaculture farmed fish (Mugil cephalus and Oreochromis mossambicus) and shellfish (Corbicula fluminea Formosa and Meretrix lusoria) were determined in Taiwan and then assessed cancer and non-cancer risks for those consuming these kinds of seafood. Results indicated that C. fluminea Formosa accumulated the highest average concentration of total PAHs (43.0 ± 11.3 ng/g wet weight) while M. lusoria contained the lowest concentration (20.0 ± 5.8 ng/g) among all species. The low-molecular-weight PAHs were dominant for both fish and shellfish, which consistent with other studies. Notably, parts of high-molecular-weight PAHs were found in shellfish whereas that was little in fish. The calculated hazard quotients (HQ) of all PAHs were smaller than 1 and the incremental lifetime cancer risks (ILCR) for Benzo[a]pyrene were below 1 × 10-5, suggesting that PAHs in the collected seafood could pose a low hazard to residents. Although the results indicated that the studied seafood is safe for human consumption, children and seniors post relatively higher risks, suggesting that it needs to continue monitoring and control the PAHs concentration in seafood and the associated environments.


Asunto(s)
Hidrocarburos Policíclicos Aromáticos , Animales , Acuicultura , Niño , Monitoreo del Ambiente , Contaminación de Alimentos/análisis , Humanos , Hidrocarburos Policíclicos Aromáticos/análisis , Estanques , Medición de Riesgo , Alimentos Marinos/análisis , Taiwán
3.
J Hazard Mater ; 421: 126743, 2022 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-34364212

RESUMEN

Limited knowledge of the combined effects of water and sediment properties and metal ionic characteristics on the solid-liquid partitioning of heavy metals constrains the effective management of urban waterways. This study investigated the synergistic influence of key water, sediment and ionic properties on the adsorption-desorption behavior of weakly-bound heavy metals. Field study results indicated that clay minerals are unlikely to adsorb heavy metals in the weakly-bound fraction of sediments (e.g., r = -0.37, kaolinite vs. Cd), whilst dissociation of metal-phosphates can increase metal solubility (e.g., r = 0.61, dissolved phosphorus vs. Zn). High salinity favors solubility of weakly-bound metals due to cation exchange (e.g., r = 0.60, conductivity vs. Cr). Dissolved organic matter does not favor metal solubility (e.g., r = -0.002, DOC vs. Pb) due to salt-induced flocculation. Laboratory study revealed that water pH and salinity dictate metal partitioning due to ionic properties of Ca2+ and H+. Selectivity for particulate phase increased in the order Cu>Pb>Ni>Zn, generally following the softness (2.89, 3.58, 2.82, 2.34, respectively) of the metal ions. Desorption followed the order Ni>Zn>Pb>Cu, which was attributed to decreased hydrolysis constant (pK1 = 9.4, 9.6, 7.8, 7.5, respectively). The study outcomes provide fundamental knowledge for understanding the mobility and potential ecotoxicological impacts of heavy metals in aquatic ecosystems.


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , Adsorción , China , Ecosistema , Monitoreo del Ambiente , Sedimentos Geológicos , Metales Pesados/análisis , Agua , Contaminantes Químicos del Agua/análisis
4.
J Hazard Mater ; 421: 126712, 2022 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-34388919

RESUMEN

Aquaculture is increasing at the global scale, and beneficial reuse of wastewater is becoming crucial in some regions. Here we selected a unique tertiary treatment system for study over a one-year period. This experimental ecosystem-based approach to effluent management included a treated wastewater pond (TWP), which receives 100% effluent from a wastewater treatment plant, and an aquaculture pond (AP) that receives treated water from the TWP for fish production. We examined the fate of a wide range of pharmaceutically active compounds (PhACs) in this TWP-AP system and a control pond fed by river water using traditional grab sampling and passive samplers. We then employed probabilistic approaches to examine exposure hazards. Telmisartan, carbamazepine, diclofenac and venlafaxine, exceeded ecotoxicological predicted no effect concentrations in influent wastewater to the TWP, but these water quality hazards were consistently reduced following treatment in the TWP-AP system. In addition, both grab and passive sampling approaches resulted in similar occurrence patterns of studied compounds, which highlights the potential of POCIS use for water monitoring. Based on the approach taken here, the TWP-AP system appears useful as a tertiary treatment step to reduce PhACs and decrease ecotoxicological and antibiotic resistance water quality hazards prior to beneficial reuse in aquaculture.


Asunto(s)
Preparaciones Farmacéuticas , Contaminantes Químicos del Agua , Animales , Acuicultura , Ecosistema , Monitoreo del Ambiente , Estanques , Aguas Residuales/análisis , Agua , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
5.
J Hazard Mater ; 421: 126693, 2022 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-34396957

RESUMEN

Researchers interested in a paper's statement or aiming to acquire useful information from scientific papers rely heavily on references. Additionally, calculation accuracy is important for ensuring the technical soundness of scientific papers. However, inaccurate citations and calculations are common in scientific literature. A recently published paper in the Journal of Hazardous Materials reported a study on microplastics in groundwater and surface water from coastal south India (Tamil Nadu state) and the heavy metal adsorption capacities of different polymers. In this study, we identified critical calculation errors and incorrect reference citations.


Asunto(s)
Agua Subterránea , Metales Pesados , Contaminantes Químicos del Agua , Monitoreo del Ambiente , India , Microplásticos , Plásticos , Agua , Contaminantes Químicos del Agua/análisis
6.
Sci Rep ; 11(1): 20140, 2021 10 11.
Artículo en Inglés | MEDLINE | ID: mdl-34635728

RESUMEN

The global economic activities were completely stopped during COVID-19 lockdown and continuous lockdown partially brought some positive effects for the health of the total environment. The multiple industries, cities, towns and rural people are completely depending on large tropical river Damodar (India) but in the last few decades the quality of the river water is being significantly deteriorated. The present study attempts to investigate the river water quality (RWQ) particularly for pre- lockdown, lockdown and unlock period. We considered 20 variables per sample of RWQ data and it was analyzed using novel Modified Water Quality Index (MWQI), Trophic State Index (TSI), Heavy Metal Index (HMI) and Potential Ecological Risk Index (RI). Principal component analysis (PCA) and Pearson's correlation (r) analysis are applied to determine the influencing variables and relationship among the river pollutants. The results show that during lockdown 54.54% samples were brought significantly positive changes applying MWQI. During lockdown, HMI ranged from 33.96 to 117.33 with 27.27% good water quality which shows the low ecological risk of aquatic ecosystem due to low mixing of toxic metals in the river water. Lockdown effects brought river water to oligotrophic/meso-eutrophic condition from eutrophic/hyper-eutrophic stage. Rejuvenation of river health during lockdown offers ample scope to policymakers, administrators and environmentalists for restoration of river health from huge anthropogenic stress.


Asunto(s)
COVID-19/prevención & control , Control de Enfermedades Transmisibles/normas , Ríos/química , Contaminantes Químicos del Agua/análisis , Calidad del Agua , COVID-19/epidemiología , COVID-19/transmisión , Monitoreo del Ambiente/estadística & datos numéricos , Restauración y Remediación Ambiental/estadística & datos numéricos , Humanos , Metales Pesados/análisis
7.
Environ Monit Assess ; 193(11): 714, 2021 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-34637012

RESUMEN

This paper assesses the concentrations, spatial distribution, compositional patterns, and sources of polycyclic aromatic hydrocarbons (PAHs) in the dissolved aqueous phase along the Abou Ali River course. The 16 priority PAHs, listed by the USEPA, were investigated in surface- and groundwater samples for 2 years starting August 2015 and ending in March 2017. Statistical analysis was done by using the ANOVA test at p < 0.05. The spatial distribution analysis and illustration were done using the ARC GIS software. The total PAHs concentration in surface and groundwater samples varied between not detected to 15.162 ng mL-1 and not detected to 0.635 ng mL-1, respectively. The highest concentration of PAHs in surface water was observed at site S16, downstream of the river. However, the absence of PAHs was noticed at sites S1 and S2 of the upstream. The contamination levels of PAHs were found to be high in surface water samples, and low in groundwater samples. The 5- and 6-ring PAHs were the most abundant species among others in surface water samples, whereas the 3-ring PAHs were the most abundant in groundwater. Pyrogenic inputs deriving from fuel combustion, incineration, and miscellaneous burning were found to be the main PAH sources in surface and groundwater without ignoring the contribution of petrogenic inputs in some areas.


Asunto(s)
Agua Subterránea , Hidrocarburos Policíclicos Aromáticos , Contaminantes Químicos del Agua , Monitoreo del Ambiente , Líbano , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes Químicos del Agua/análisis
8.
Environ Monit Assess ; 193(11): 715, 2021 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-34637024

RESUMEN

Artisanal small-scale mining has been part of Ghana's history, but recent public outcry on the devastating impacts of the phenomenon on water bodies, due to expansion in the sector, has led to clamp downs by various governments on the activity. This has called for evaluation of the water quality of the South-western Rivers System, which are small-scale mining endemic areas. Thirty-five river samples were collected in July 2018 and were analyzed for physico-chemical parameters using procedures outlined in the Standard Methods for the Examination of Water and Wastewaters. The results revealed that the rivers are polluted with Fe and Cu, accompanied by very high levels of turbidity (mean = 488 NTU) and total suspended solids (TSS) (mean = 382 mg/L). NH3-N, PO4-P, BOD, and DO levels indicated mild pollution in the waters. Pollution of the rivers is attributable to impacts of artisanal small-scale mining, surface run-off as a result of high intensity rainfall, anthropogenic (indiscriminate waste disposal) and geogenic factors such as dissolution of minerals from the soil zone. It was observed that, if not strictly regulated, turbidity and TSS levels arising mainly from illegal small-scale mining activities could lead to shutdowns of a number of Ghana Water Company Limited treatment plants, leading to water supply challenges in the study area.


Asunto(s)
Ríos , Contaminantes Químicos del Agua , Monitoreo del Ambiente , Ghana , Contaminantes Químicos del Agua/análisis , Calidad del Agua
10.
J Environ Sci (China) ; 110: 38-47, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34593193

RESUMEN

To assess groundwater nitrate contamination and its human health risks, 489 unconfined groundwater samples were collected and analyzed from Zhangjiakou, northern China. The spatial distribution of principle hydrogeochemical results showed that the average concentrations of ions in descend order was HCO3-, SO42-, Na+, Ca2+, Cl-, NO3-, Mg2+ and K+, among which the NO3- concentrations were between 0.25 and 536.73 mg/L with an average of 29.72 mg/L. In total, 167 out of 489 samples (~ 34%) exceeded the recommended concentration of 20 mg/L in Quality Standard for Groundwater of China. The high NO3- concentration groundwater mainly located in the northern part and near the boundary of the two geomorphic units. As revealed by statistical analysis, the groundwater chemistry was more significantly affected by anthropogenic sources than by the geogenic sources. Moreover, human health risks of groundwater nitrate through oral and dermal exposure pathways were assessed by model, the results showed that about 60%, 50%, 32% and 26% of the area exceeded the acceptable level (total health index>1) for infants, children, adult males and females, respectively. The health risks for different groups of people varied significantly, ranked: infants> children> adult males>adult females, suggesting that younger people are more susceptible to nitrate contamination, while females are more resistant to nitrate contamination than males. To ensure the drinking water safety in Zhangjiakou and its downstream areas, proper management and treatment of groundwater will be necessary to avoid the health risks associated with nitrate contamination.


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , China , Monitoreo del Ambiente , Femenino , Humanos , Masculino , Nitratos/análisis , Medición de Riesgo , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
11.
J Environ Sci (China) ; 110: 55-72, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34593195

RESUMEN

Jiaxing created a precedent using bypass riparian marshes to purify micro-polluted water sources in China. Pond-wetland complex with constructed root channel technology becomes a paradigm which can be analogized as "human-body wetland model" based on bionics or biomimetics. Heterogeneous plant-bed/ditch system with highly active land/water ecotone interfaces, especially meandering boundaries, breeds many biochemical reactions "living areas". Optimization of hydraulic regulation promotes redox environment alternations and wetland treatment efficiency. Here we reported a series of upgrades and performances in Guanjinggang wetland after the Shijiuyang prototype. Morphological reform of plant-bed/ditch system played a vital role. Spatially root channel zone was main force of wetland purification, and temporally the treatment effect was higher in low-temperature seasons indicating non-temperature dependent mechanisms worked. Water pollution comprehensive index improved steadily from IV to III, and comprehensive pollution load was reduced by ca. 40%-60%. Comprehensive evaluation function value further showed the gradients purification effect of the upgraded wetland. Ecological wetlands ameliorated source water quality, and reduced drinking water treatment reagents, thereby bringing about economic benefits. Through wetlands operation, people can see how the micro-polluted surface water becomes clear and clean, so promoting a significant social benefit. As a viable component of urban green space, wetlands could beautify regional eco-environment, freshen the air, increase urban ecological taste, and enhance the eco-environmental protection publicity. Thus, the multifunctional service values and indirect benefits are substantial. Jiaxing ecological wetlands provide a typical paradigm for water pollution remediation in developing countries and plays a leading role in technology engineering radiation effect.


Asunto(s)
Purificación del Agua , Humedales , Humanos , Ríos , Agua , Contaminación del Agua
12.
Sci Total Environ ; 781: 146691, 2021 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-34594059

RESUMEN

Levels of total mercury were measured in tissue of six species of migratory fish (alewife, American shad, blueback herring, rainbow smelt, striped bass, and sea lamprey), and in roe of American shad for two consecutive years collected from the Penobscot River or its estuary. The resultant mercury levels were compared to reference doses as established in the U.S. Environmental Protection Agency (EPA) Integrated Risk Information System and wildlife values. Mercury concentrations ranged from 4 µg/kg ww in roe to 1040 µg/kg ww in sea lamprey. Sea lamprey contained the highest amounts of mercury for both seasons of sampling. Current health advisories are set at sufficient levels to protect fishers from harmful consumption of the fish for mercury alone, except for sea lamprey. Based upon published wildlife values for mink, otter, and eagle, consumption of rainbow smelt, striped bass, or sea lamprey poses a risk to mink; striped bass and sea lamprey to otter; and sea lamprey to eagle. For future consideration, the resultant data may serve as a reference point for both human health and wildlife risk assessments for the consumption of anadromous fish. U.S. EPA works with federally recognized Tribes across the nation greatly impacted by restrictions on sustenance fishing, to develop culturally sensitive risk assessments.


Asunto(s)
Mercurio , Contaminantes Químicos del Agua , Animales , Monitoreo del Ambiente , Estuarios , Peces , Humanos , Maine , Mercurio/análisis , Ríos , Contaminantes Químicos del Agua/análisis
13.
Environ Monit Assess ; 193(11): 694, 2021 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-34611737

RESUMEN

The Prairie Pothole Region is one of the most wetland rich areas of the world and has experienced intense disturbance from increased agricultural demands and urban sprawl. This study assessed ponds across the urban gradient for the first time in the region to determine the impacts of urbanization on water quality. Thirty ponds (ten rural, ten peri-urban, and ten urban) were randomly selected and compared based on land use type and the impervious to pervious surface ratio within 1.6 km of each pond. Water quality samples were taken monthly in 2015 and 2016, across 3 and 6 months respectively. Assessment included chemical and physical parameters, which were compared spatially across the gradient and temporally between sampling periods. Results indicate disturbance from urbanization negatively impacts water quality. Spatially across the gradient, rural pond water quality was significantly different from both peri-urban and urban ponds, whereas peri-urban and urban pond water quality was not significantly different. Temporally, differences between water quality parameters and sampling periods indicate that surrounding land use, land cover, and precipitation influence parameter concentrations across the urbanization gradient. Information from this study is useful to water professionals dealing with urban development and sprawl that continue to impact water and natural habitat.


Asunto(s)
Estanques , Calidad del Agua , Ecosistema , Monitoreo del Ambiente , Urbanización
14.
Environ Monit Assess ; 193(10): 683, 2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-34596775

RESUMEN

The Coeur d'Alene Lake basin in Northwestern USA has extensive contamination from legacy mining waste, which overlaps with aquatic macrophyte habitat. We examined concentrations of arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) in three macrophytes: Elodea canadensis (submerged), Myriophyllum spicatum (submerged), and Sagittaria latifolia (emergent). We collected macrophyte tissues from five contaminated sites and one uncontaminated site. Tissue concentrations were compared to sediment quality guidelines to assess potential toxicity from metal(loid)s to macrophyte-associated biota. We used threshold and probable effect concentrations to screen for potential toxicity. For the submerged species, the highest site means ± SD (analyte mg/kg dry mass) were 96 ± 61 (As), 18 ± 1.7 (Cd), 24 ± 15 (Cu), 610 ± 392 (Pb), and 1425 ± 222 (Zn). For contaminated sites, the probable effect threshold was exceeded in 38% (As), 45% (Cd), 0% (Cu), 74% (Pb), and 67% (Zn) of submerged species concentrations. Metal concentrations in S. latifolia tubers were lower than the submerged species leaves and shoots. Tuber concentrations did not exceed the probable effect threshold for any metal. Spatial differences in concentrations were most distinct for the submerged species. Our work shows significant amounts of metals are accumulating in some macrophytes of the study area and that biota associated with this vegetation may experience toxicity based upon guideline exceedances. Additionally, managers of invasive plants (e.g., M. spicatum) should consider the ramifications of control efforts given the high metal content of some plants (e.g., disposal issue).


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , Monitoreo del Ambiente , Sedimentos Geológicos , Lagos , Metales , Metales Pesados/análisis , Contaminantes Químicos del Agua/análisis
15.
Environ Monit Assess ; 193(10): 687, 2021 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-34601622

RESUMEN

Phenolic compounds are widely spread in surface water, mainly in developing countries, where sewage and wastewater treatment are still reduced. Thus, this work quantified these pollutants in the Doce River analyzing the associated risk for the environment and human health. This river is in the state of Minas Gerais in Brazil and was recently impacted by the collapse of a mining dam that compromised the resilience of the entire watershed. For that purpose, a methodology for simultaneous identification and quantification of 17 different phenols was developed. It was possible to verify phenolic compounds' occurrence with concentration ranging from 0.13 to 24.16 µg·L-1. 2-Nitrophenol and bisphenol A appeared in all samples analyzed. The analytical method was processed using solid-phase extraction (SPE) (C18 cartridge), gas chromatography with FID, and mass spectrometry to define the analytes' retention time. For case validation, the selectivity, linearity, detection and quantification limits, sensitivity, precision, accuracy, resolution, matrix effect, and peak quality were assessed. Four different solvents were tested in the recovery-grade trials, which were dichloromethane, methanol, acetonitrile, and ethyl acetate. Among them, methanol had a better performance and was used throughout all analyses. The phenolic compounds had a recovery degree higher than 50% after SPE, regardless of the matrices.


Asunto(s)
Ríos , Contaminantes Químicos del Agua , Brasil , Monitoreo del Ambiente , Cromatografía de Gases y Espectrometría de Masas , Humanos , Fenoles/análisis , Agua , Contaminantes Químicos del Agua/análisis
16.
Environ Monit Assess ; 193(10): 689, 2021 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-34601623

RESUMEN

The objective of this study was to evaluate the occurrence of pesticides in surface and groundwater of agricultural areas of the Pampas region of Argentina and to develop an ecological risk assessment (ERA) of pesticides in freshwater ecosystems. Eight agricultural sites from south Santa Fe province, in the north of the Pampas region, were sampled seven times between 2016 and 2018. Pesticides were analysed by gas chromatography-mass spectrometry (GC/MS) and liquid chromatography-mass spectrometry (UPLC-LC/MS). Twenty compounds among herbicides, insecticides and fungicides in 84% and 79% of groundwater and surface water samples, respectively, were detected. Atrazine was the most ubiquitous pesticide, following by metolachlor, acetochlor and glyphosate, with maximum concentrations of 28, 24, 77 and 111 µg/L, respectively. An ERA was performed by employing the risk quotient (RQ) method. Atrazine, azoxystrobin, pirimiphos-methyl, acetochlor and epoxiconazole posed a high and very high risk for aquatic organisms (RQ > 1) and glyphosate, metolachlor and 2,4-D exhibited negligible to medium risk. The herbicides were the major contributors to risk. This study is the first contribution on the presence and concentration of pesticides in surface and groundwater from agricultural areas of south Santa Fe province, north Pampas region, Argentina, and a starting point for pesticide ecological risk assessment.


Asunto(s)
Agua Subterránea , Plaguicidas , Contaminantes Químicos del Agua , Argentina , Ecosistema , Monitoreo del Ambiente , Plaguicidas/análisis , Medición de Riesgo , Contaminantes Químicos del Agua/análisis
17.
Environ Monit Assess ; 193(10): 688, 2021 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-34601655

RESUMEN

At various locations around the world, environments are now becoming greatly polluted by heavy metals, while damage is being done to soil and aquatic life with serious implications for humanity as well. Once heavy metals enter the ecosystem, they persist for a long time, and they are very difficult to eliminate. Discharging of industrial wastes enriched with heavy metals substantially pollutes the soil, water, and air. This study investigated the levels of heavy metals around the industrial area of Brahmanbaria, which is located in Chittagong Division, Bangladesh. Samples of soil, wastewater, vegetable, and grass were collected from the industrial area. The heavy metals were quantified using atomic absorption spectroscopy. The heavy metals found in soil were chromium (Cr) 8.2-18.8, lead (Pb) 3.5-18.3, copper (Cu) 4.6-10.8, zinc (Zn) 48.5-273.4, nickel (Ni) 10.06-26.9, and cadmium (Cd) 0.2 mg/kg, respectively. The metal contents in the wastewater were Cr 0.03-0.5, Pb 0.01-0.05, Cu 0.01-0.02, Zn 0.6-11.2, Ni 0.03-0.14, and Cd 0.003 mg/L, respectively. The metal contents in vegetable and grass were Cr 81.5-247.8, Pb 10.3-34.1, Cu 5.5-6.3, Zn 419.8-435.3, and Ni 8.7-15.5 mg/kg, respectively. The amount of metal in the soil, wastewater, and vegetables and grass followed the sequences: Zn > Cr > Ni > Pb > Cu > Cd, Zn > Cr > Ni > Pb > Cu > Cd, and Zn > Cr > Pb > Ni > Cu, respectively. Compared to the WHO guidelines, the soil in the study area was not polluted with Pb, Cu, and Cd but was moderately polluted with Cr, Zn, and Ni. Continual accumulation of metals in the soil, vegetables and grass could pose a serious risk to the environment as well as many life forms.


Asunto(s)
Metales Pesados , Suelo , Bangladesh , Ecosistema , Monitoreo del Ambiente , Aguas Residuales
18.
Environ Monit Assess ; 193(10): 690, 2021 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-34601695

RESUMEN

The rapidly changing marine environmental chemistry associated with growing industrialisation, urban population expansion, and the unabated rise in atmospheric CO2 necessitates monitoring. Traditional approaches using metres, dataloggers, and buoys to monitor marine acidification have limited application in coastal oceans and intertidal zones subjected to direct wave action. The present study trialled a system to biomonitor coastal acidification (carbonate ion and pH) based on the dissolution of living gastropod shells. We extended on an approach that ranked shell erosion (SER) in Nerita chamaeleon (Nc) in environments where such erosion was found to correlate with exposure to acidified water. We assessed the spatial scale at which the Nc-SER marker could detect change in acidification along rocky shores, and whether snail body size affected this marker. We found that proportional and unique Nc-SERs not only varied between acidified and non-acidified reference shores at a coarse spatial scale (10 km), but also in predictable ways at fine scales (metres), vertically and horizontally within a shore. Differences between acidified and reference shores in the relationship for snail size and Nc-SER were accentuated by less weathered shells at reference localities, highlighting the value of including small, juvenile snails in monitoring protocols. Gastropod shells are shown to be useful for assessing point sources of acidification and the spatial area of affected coastal zones. This cost-effective and easy-to-use approach (potentially even by citizen-scientists) offers an early warning system of acidification of rocky shore ecosystems, where the deployment of instruments is precluded.


Asunto(s)
Ecosistema , Agua de Mar , Animales , Monitoreo del Ambiente , Concentración de Iones de Hidrógeno , Caracoles
19.
Environ Monit Assess ; 193(11): 703, 2021 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-34623531

RESUMEN

The Nile River is the soul of Egypt, providing more than 95% of its freshwater demand. However, it receives different pollutants discharged into the water body along its stretch from Aswan (downstream of the High Dam) to Cairo, which is approximately 950 km. Alternatively, sediments play an important role in the dynamics of the entire aquatic environment and act as a sink or a source of pollution in the overlying water under various conditions. This study assessed sediment quality and its heavy metal levels. Several indices and human health risks were determined to assess the potential ecological risk of the Nile River sediment. On the basis of the index results, Cd registered the highest pollution ranking, whereas Fe, Mn, Zn, Cu, and Ni had the lowest effect. In another context, southern sites represented the lowest ecological risk relative to the central and northern sectors. The results of the noncarcinogenic hazard indices, hazard quotient, and hazard index in addition to the lifetime cancer risk were below the acceptable international limits, confirming that there are no adverse effects on the exposed population due to the Nile sediment.


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , Egipto , Monitoreo del Ambiente , Sedimentos Geológicos , Humanos , Metales Pesados/análisis , Medición de Riesgo , Contaminantes Químicos del Agua/análisis
20.
Environ Monit Assess ; 193(11): 709, 2021 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-34625850

RESUMEN

This study assessed the contamination of streams with potentially toxic elements (PTEs) in sediments around mining, quarrying, and cultivation areas in Akamkpa and environs Southeastern Nigeria. Analysis done using ICP MS technique shows that barium (Ba) and lead (Pb) recorded mean concentrations above their average shale content (ASC) in stream sediments. Chromium (Cr) exceeded Canadian Interim Sediment Quality Guideline (ISQG) and US Environmental Protection Agency (USEPA) screening benchmark value. Pb exceeded Canadian ISQG value but tallies with USEPA benchmark value. Pearson's correlation exhibited significant correlation (p < 0.01) of molybdenum (Mo) with copper (Cu) and Pb; Cu with Pb, vanadium (V), and Ba; V with Cu, Pb, iron (Fe), Ba, and beryllium (Be); and Fe with Be and V. Principal component (PC 1) consists of Pb, Mo, cobalt (Co), Cu, arsenic (As), Cr, V, and nickel (Ni) and showed significant correlation. Geo accumulation index (I-geo) values for Mo, Cu, V, Pb, Zn, Ni, Co, Mn, and Ba fall under unpolluted (0) to moderately polluted (1-2) classes. Maximum enrichment factor (EF) values show extremely high and significant enrichment of Ba and Pb in few locations. Co, Cr, Cu, Mn, and Zn possess maximum EF values classified as moderate enrichment. Ni, Mo, As, and V obtained maximum EF values classified as depleted to minimal enrichment. Modified pollution index (MPI) values showed high PTEs contamination in mostly cultivation locations. Single element potential ecological risk (EiR) mean values trend EiR (As) > EiR (Pb) > EiR (Co) > EiR (Cr) > EiR (Cu) > EiR (V) > EiR (Ni) > EiR (Zn). Comprehensive potential ecological risk (RI) shows medium risk "B" and strong risk "C" levels in few locations. The use of multiple pollution indices such as I-geo, EF, EiR, and RI in pollution assessment indicated similar trend of PTEs contamination of stream sediments. Levels of PTEs contamination are elevated in cultivation areas more than in granite quarrying and mining areas. This study serves as a benchmark for conducting suitable environmental management strategies to scientists in Nigeria and other parts of the world.


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , Sulfato de Bario , Canadá , Monitoreo del Ambiente , Sedimentos Geológicos , Metales Pesados/análisis , Nigeria , Medición de Riesgo , Ríos , Dióxido de Silicio , Estados Unidos , Contaminantes Químicos del Agua/análisis
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