Contaminant Loads Research Articles

Determination of heavy metals concentration in some sachet water commonly in Abuja Municipal Council, Nigeria

The aim of the study was undertaken to assess heavy metal concentration in some sachet water commonly consumed in Abuja Municipal Council, Nigeria. This was done by measuring heavy metal concentration using Atomic Absorption Spectrometer at the advance chemistry laboratory, Sheda Science and Technology Complex (SHETSCO), FCT, then estimating carcinogenic and non carcinogenic exposure, contamination factor, degree of contamination and pollution load index. The samples were all obtained randomly within Abuja Metropolis. The carcinogenic and non- carcinogenic exposure are far less than 1. The concentration of the heavy metals in sachet water for Cd, Mn, Pb, Cu and Zn are 0.019 mg/l, 0.173 mg/l, 0.219 mg/l, 1.250 mg/l and 0.0760 mg/l respectively. The value of Cd, Pb exceed the recommend standard of 0.01 set by WHO (2008) while the concentration of Mn, Cu and Zn are below the permissible limit of 0.5 mg/l, 2 mg/l and 5 mg/l. The estimated heavy metal risk resulting from exposure to Cd and the estimated concentration of Pb in this study, was higher than the acceptable limit range provided by WHO. This indicates adverse health effects for people who consume sachet water in Abuja municipal council.

Species and reproductive status influence element concentrations in bat fur

To assess the impact of increasing pollutant levels on wildlife, we measured chemical contaminant loads in bats with different habitat and dietary preferences. Samples were taken from the fur of bats (Eptesicus nilssonii, Myotis brandtii, Myotis mystacinus and Plecotus auritus) to measure concentrations of 55 elements by inductively coupled plasma mass spectrometry (ICP-MS). Variations in element concentrations between different bat groups (species, sex, reproductive status) were analysed with a focus on arsenic (As), mercury (Hg) and lead (Pb) as these are known to cause specific health concerns in wildlife. For M. brandtii we found the highest As concentrations, especially in lactating bats, with a maximum exceeding those from other studies where bats had compromised health. Whereas for M. mystacinus there was a negative correlation between body condition index (BCI) and As concentration, indicating a potential danger for bats in the study area. In M. mystacinus and M. brandtii Hg concentrations were higher for sixteen individuals than in other studies where bats suffered genotoxic effects, although median levels were still below this threshold. Lactating bats from P. auritus and M. brandtii had higher Hg concentrations than bats of other reproductive status, which could endanger offspring as Hg can be transferred through lactation. In females from M. mystacinus Pb concentrations were more than three times higher compared to males. There was also a negative correlation between Pb concentration and BCI, which could mean that Pb has an adverse effect on health. Although many other biotic and abiotic factors should be considered, some of the variations in element concentrations could be due to different behaviours (foraging, roosting, etc.) in the studied species. The high levels of chemical contamination in some of the bats in our study, particularly reproductive individuals, is of conservation concern as bats are important agents for insect control.

Profiling the Contamination Level and Pollution Load Index of Borehole Water from Esako West LGA, Edo State, Nigeria

Fresh water has continued to decrease both in quality and quantity with a wide variety of pollutants entering into fresh water resources. In this research the quality of fresh water was being accessed using standard method of analysis of water. Physiochemical parameters and heavy metal content were determined and data was assessed using contamination factors, degree of contamination and pollution load index result revealed that borehole water at Esako west LGA was slightly contaminated by phosphate (0.16 mg/l) and over 5 times the WHO standard. The acidic water (pH 6) was observed over 200 mg/l of carbon dioxide the contamination factor for zinc were generally greater than 1, while other parameter had values of contamination factors less than 1. In conclusion, borehole water at Esako west contaminated and slightly polluted through the locals continued to consume this water, there is a need for treatment to remove phosphate whose source may be from phosphate rocks in the area or sipping from phosphate fertilizer in farms.

Spatiotemporal Patterns of Ammonia Nitrogen and Chemical Oxygen Demand in the Huaihe River–Hongze Lake System (Eastern China)

Understanding variations in contaminant concentrations and exploring their driving factors are essential for pollution control and water environment improvement. The Huaihe River Basin, as an important region in the eastern region of China, has attracted much attention to its water environment issues in recent years. Therefore, an in-depth analysis of spatiotemporal patterns of water quality parameters was carried out on the Huaihe River–Hongze Lake system, for the period 1998–2018, using the Mann–Kendall test (MKT) and wavelet transforms (WTs). Significant decrease trends of ammonia nitrogen (AN) and chemical oxygen demand (COD) concentrations were detected in the Huaihe River (HR) before 2008 using the MKT. High concentration in the contaminant load was a result of the effect of increased construction and decreased forest on increasing input of pollutants during this period. The results of the WT showed how factors (e.g., streamflow and water temperature), except land use, affect the variations in AN and COD concentrations. The comparison of spatiotemporal patterns of AN and COD between the HR and Hongze Lake (HL) showed their differences in contaminant transport regimes. The contaminants were rapidly transported downstream along the HR with high streamflow during the wet season, while these in the HL were less responsive due to the long residence time of the water body. In addition, rebounds of contaminant concentrations occurred many times at the confluence between the HR and the HL due to strong river–lake interactions, especially in the flood season. These results have implications for future water environment management in the Huaihe River Basin and in similar settings worldwide.

Source separated graywater: Chemistry, unit operations, and criteria towards re-use

Water scarcity due to increasing population, climate change, and natural resource depletion has led to exploring alternate sources of useable water through the treatment and reuse of wastewater. Additionally, increasing complexity of logistics and costs to transport water are driving the development and demonstration of decentralized wastewater treatment units. Graywater, or wastewater that does not include water from toilets, is a particularly promising source of water for reuse due to lower contaminant loading when compared to other wastewater streams. In this study, ultrafiltration (UF) and reverse osmosis (RO) membrane technologies with ultraviolet (UV) disinfection was evaluated for the treatment of low strength graywater from shower facilities over a six-month period. With >100,000-gallons of source separated graywater treated, this is one of the largest and most comprehensive graywater treatment events to date. Water reuse guidelines were established to reflect the most stringent reuse requirements in the United States. The combined treatment train of UF and RO met compliance metrics for all analytes of interest. This UF/RO system not only addresses issues with water quality, but water quantity as well. A water recovery rate of 85 % multiplies the effective volume of usable water by a factor of 6.5, creating a significant reduction in volume required. Both the quality of the treated water and the effective volume gains from the multiplier effect make decentralized treatment of source separated graywater by UF/RO a viable technology to address physical and economical water scarcity. This system can be used in austere environments to capture a currently untapped source of water for reuse.

Assessment of variations in microbiological quality of water in the newly constructed rainwater-harvesting system storage tank

Proper harvesting of rainwater requires a good knowledge of the storage conditions and the nature of physico-chemical and microbiological contaminant loads on the harvested water. This will help to determine the nature and level of treatment required. This study assessed the variations in the microbiological quality of water stored in a newly constructed galvanized steel tank over the course of one rainy season in Afikpo, Nigeria. A 2.0 mm thick galvanized steel tank of 1.728 m3 capacity was constructed together with water collection system including coarse mesh, gutter, funnel, conduits, first-flushing device and filter. Rainwater was collected into the tank, sampled, discharged, and rinsed with chlorinated water at each sampling episode throughout the rainy season at Afikpo, from April to November 2021. The water samples were tested in the laboratory for total coliform and faecal coliform. The weekly concentrations of total coliform range between 90CFU/100 ml and 320CFU/100 ml; the mean is 177CFU/100 ml. The weekly concentrations of faecal coliform fall between 30CFU/100 ml and 261CFU/100 ml; the mean is 108CFU/100 ml. These results indicate that the concentrations of the two pathogens are far above the zero limit recommended by the World Health Organization (WHO) and Nigerian Standards for Drinking Water Quality (NSDWQ) . Hence, the rooftop-harvested rainwater is unsafe for human consumption without treatment. Boiling or chlorine treatment is needed. Public health authorities in Afikpo should sensitize the public on the dangers of consuming untreated rainwater as is the practice found among many in the area.

Controls on the Generation and Geochemistry of Neutral Mine Drainage: Evidence from Force Crag Mine, Cumbria, UK

Neutral mine drainage (NMD) at Force Crag mine in north-west England has a circumneutral pH and high levels of Zn contamination. A long-term geochemical and hydrological dataset from this site was analysed using a novel molar mass balance approach, which demonstrated that the water chemistry is dominated by species released by the oxidation of sulphides: sphalerite (Zn, Cd, Ni), galena (Pb, mostly removed by adsorption to ferrihydrite) and pyrite (Fe, mostly precipitates as ferrihydrite). The calculations show that the sphalerite:galena:pyrite oxidation ratio is ~1:2:1, but the mine water chemistry is dominated by Zn due to the removal of Pb and Fe by adsorption/precipitation. The acidity released by pyrite oxidation is neutralised by the dissolution of calcite and, to a lesser extent, chlorite. The presence of pyrite is responsible both for the release of acidity and the removal of some contaminant metals by adsorption on ferrihydrite. The concentrations of sulphate, Zn, Cd and Ni in the mine water decrease with increasing flow due to dilution; modest increases in metal flux with flow probably reflect increased oxidation due to greater amounts of oxygenated water flowing through the mine. In contrast, Al, Pb and Cu concentrations are positively correlated with flow due to the flushing of these metals adsorbed to ferrihydrite particles. The influence of temperature is relatively subtle; metal fluxes are a balance between abiotic oxidation (which increases at higher temperatures and flows) and bacterially mediated oxidation (which is depressed at high flow rates when temperatures decrease below 10 °C). These conclusions apply to NMD mine water throughout the UK and elsewhere in the world, including mines hosted in both limestone and silicate rocks. The molar mass balance approach, together with synchronous flow and geochemistry data, provides crucial information for effective mine-water-treatment system design by elucidating the critical roles of flow rate and temperature in determining contaminant concentrations and loads.

Pollution status monitoring and indices development for evaluating sustainable environmental management practices (SEMP) in Quaid-e-Azam Industrial Estate, Pakistan

The economic growth of the global industrial sector has become a grave concern to immensely degrade the environment in recent years. The industries lack an effective environmental management plan to mitigate environmental contamination and pollution load by following good practices such as less consumption of raw materials, waste reduction, wastewater treatment, and pollution control. Significantly, the current study aims to investigate the environmental baseline conditions of Quaid-e-Azam Industrial Estate (QIE) and design Environmental Management Plan (EMP) to alleviate the impacts of industrial wastewater effluents, ambient air, ambient noise level, and solid waste. In addition, this study monitors the current pollution status and develops the air/water quality indices to evaluate sustainable environmental management practices (SEMP) in QIE. The obtained key finding reported a poor wastewater quality index ranging from 100 to 150. Furthermore, the air quality index suggested that ambient air in the vicinity of QIE varied from 52 to 72, which is evident that ambient air is moderately polluted and pose risk to public health. Additionally, the ambient noise level was considerably 12.8% higher in the morning and 18.7% higher than the prescribed level in the afternoon. Furthermore, approximately 10 t of solid waste was collected regularly from the industrial waste pits. Around 85.8% were moderately polluting ambient air whereas only 5.1% highly deteriorating ambient air. Significantly, a detailed environmental management plan (EMP) was designed to include impact identification, mitigation measures, frequency of monitoring the effectiveness of mitigatory measures, and assigning of responsibilities. Overall, the environmental management plan should become an integral part of the overall management system to achieve sustainable development goals (SDGs), including sustainable cities and communities (SDG11), life below water (SDG14), and life on land (SDG15).

Bacteriological Evaluation Of Nigerian Currency Notes From Selected Handlers In Ilesha Metropolis Of Osun State, Nigeria

Background: Peoples from various background and from difffferent works of life with difffferent hygienic status always engaged in  physical transactions with a legal tender of varied denominations for exchange of goods and services, and one of the legal tender  offiffifficially recognized in Nigeria is called naira. This study evaluated bacterial contaminants onnaira notes in circulations from  selected handlers with specifific profession and determined the resistance of the isolates to conventional antibiotic in use.  Methods: A  total of 160 samples of currency notes 20 each of 8 existing denominations in Nigeria, collected from selected participants  of various professions soaked in ringer's solution were serially diluted, subculture to various bacteriological media, Gram  stained and biochemically characterized. Determination by antibiogram study was carried out,with a view to identifying resistance risk  factors that could be associated with these contaminatedcurrency notes.  Results: The microbial load was found to be higher in lower denominations irrespective of their polymer status. The total bacterial  count per milliliter varied between 2.28 ×104 and 4.20×107 CFU, while the percentage distributions of isolates; Staphylococcus aureus  (36.8%), Escherichia coli (31.5%), Bacillus spp (3.7%) and Pseudomonas aeruginosa (27.5%) and varied resistance to antibiotics used were  recorded.  Conclusion: Bacterial antibiotic resistance has been associated with treatment failure, high health cost  burden and loss of manpower  hours due to over hospitalization. The microbial contaminant loads capable of causing opportunistic infection were found to be  present in currency notes examined. The alarming resistance of bacteria to selected conventional antibiotics used in this study, serves  an indication of potential threat of contaminated currency notes to public health. &nbsp

Cumulative environmental risk assessment of metals and polycyclic aromatic hydrocarbons from ship activities in ports

Marine environmental risk assessments rarely consider the cumulative risk from multiple contaminants and sources. Ships give rise to a range of contaminants, originating from different onboard sources, resulting in contaminant loads to the marine environment. Here, the Ship Traffic Emission Assessment Model (STEAM), in combination with the hydrodynamic and chemical fate model MAMPEC, was used to calculate loads and predicted environmental concentrations (PECs) of metals and polycyclic aromatic hydrocarbons, in four ports. PECs were compared to the predicted no effect concentrations (PNEC) to assess environmental risk from the different onboard sources, both separately and cumulatively. The results show that three out of four ports were subject to unacceptable risk. This study highlights the importance of accounting for multiple contaminant sources when assessing the marine environmental risks of shipping and challenges the suitability of the proposed new international guidelines on how to assess risk of scrubber water discharge.

Wastewater reuse and predicted ecological risk posed by contaminant mixtures in Potomac River watershed streams

AbstractA wastewater model was applied to the Potomac River watershed to provide (i) a means to identify streams with a high likelihood of carrying elevated effluent‐derived contaminants and (ii) risk assessments to aquatic life and drinking water. The model linked effluent discharges along stream networks, accumulated wastewater, and predicted contaminant loads of municipal wastewater constituents while accounting for instream dilution and attenuation. Simulations using 2016 data suggested that nearly 30% (8281 km) of streams were wastewater impacted. Low‐ to medium‐order streams had the largest range of accumulated wastewater (ACCWW%) values. ACCWW% exceeded a 1% threshold at >39% of drinking‐water intakes (varied by temporal condition). Risk assessments of municipal wastewater‐contaminant mixtures indicated that 22% (1479 km) of streams impacted by municipal wastewater (5.5% of all reaches modeled) may pose high risk to aquatic organisms under mean‐annual conditions, with fish more susceptible to chronic‐exposure effects relative to other taxa. Risk varied temporally and by stream order, with the greatest risk occurring in the summer in small streams. These findings suggest that wastewater may be an important factor contributing to environmental degradation in the Potomac River watershed.

TOP-EVs: Technology of Protein delivery through Extracellular Vesicles is a versatile platform for intracellular protein delivery.

Extracellular vesicles (EVs) have emerged as biocompatible drug delivery vehicles due to their native ability to deliver bioactive cargo to recipient cells. However, the application of EVs as a therapeutic delivery vehicle is hampered by effective methods for endogenously loading target proteins inside EVs and unloading proteins after delivery to recipient cells. Most EV-based engineered loading methods have a limited delivery efficiency owing to their inefficient endosomal escape or cargo release from the intraluminal attachment from the EV membrane. Here, we describe the 'Technology Of Protein delivery through Extracellular Vesicles' (TOP-EVs) as a tool for efficient intracellular delivery of target proteins mediated via EVs. The vesicular stomatitis virus glycoprotein and the rapamycin-heterodimerization of the FKBP12/T82L mutant FRB proteins were both important for the effective protein delivery through TOP-EVs. We showed that TOP-EVs could efficiently deliver Cre recombinase and CRISPR/Cas9 ribonucleoprotein complex in vitro. Moreover, our results demonstrated that the capacity of TOP-EVs to deliver intracellular proteins in recipient cells was not an artifact of plasmid contamination or direct plasmid loading into EVs. Finally, we showed that TOP-EVs could successfully mediate intracellular protein delivery in the liver in vivo. Taken together, TOP-EVs are a versatile platform for efficient intracellular protein delivery in vitro and in vivo, which can be applied to advance the development of protein-based therapeutics.

Characteristic of the Ethanol Extract of Carthamus tinctorius L. Flowers and its Antioxidant Activity

Safflower plant (Carthamus tinctorius L.) has been reported to be effective for treating people with measles, hypertension, stomach ache, malaria and cholesterol issues. This study aims to assess specific and non-specific parameters of characteristics for the ethanol extract of C. tinctorius L. flowers and its antioxidant properties. The specific parameters include the extract’s organoleptic properties, while the non-specific parameters include the drying shrinkage, microbial contamination content, ash content, as well as the extract’s solubility in water and ethanol according to Materia Medica Indonesia and Pharmacopeia Herbal Indonesia. An antioxidant activity assay was performed using the DPPH method. According to the results, the deep red, viscous organoleptic extract had a distinctive odor, as well as an astringent or chelate taste, and an Rf value of 0.79. Furthermore, the extract contained 0.12% of water-soluble compounds, 0.22% ethanol-soluble compounds, and several phytochemical groups, including flavonoids, saponins, triterpenoids, tannins, quinones, and steroids. According to the non-specific parameters, the extracts demonstrated 1.02%, 0.2237%, 0.96%, 0.23%, and 0.91% for weight, acid-insoluble ash content, dry shrinkage, ash content, and water content, respectively. Meanwhile, the microbial contaminant load was ˂ 1.0 × 10-1 colony/mL, alongside ˂ 1.0 × 10-1 colony/mL of mold/yeast. The C. tinctorius L. ethanol extract was observed to show significant antioxidant activities, evidenced by an IC50 which measured 2.511ppm, based on DPPH analysis. A similar outcome was also reported for the ethanol flower extract, which was further determined to fulfil both non-specific and specific standardization parameters.

Consequences of sea level rise for high metal(loid) loads in the Ría of Huelva estuary sediments

Ría of Huelva, located in southwestern Spain, is a highly metal(loid)-contaminated estuary system where sediments are exceeding action limits in an increasing order for Cd, Zn, Pb, Cu, and As. With a predicted sea level rise over the next 50 years, the estuary will be subject to flooding with brackish water or seawater. To evaluate the risk of metal(loid) mobilization under future climate scenarios, different locations along the estuary were sampled at different depths. Samples were flooded with river water, brackish water, and seawater under different short- and long-term laboratory setups. Potential metal(loid) mobilization showed that water quality standards for As, Pb, Zn, Ni, Cu, and Cd could be exceeded upon seawater flooding. However, metal(loid) mobilization was not predictable solely based on sediment loads. The driving factors for cation and anion mobility were identified to be mainly pH under low salinity and competitive desorption under high salinity conditions. Further drivers such as wave movement or labile C input in C-limited systems were found to enhance metal(loid) mobilization. Long-term flooding of intact sediment cores revealed that sea level rise will have different effects on the estuary system depending on duration of flooding. Short-term flooding in the near future will first affect alkaline sediments and enhance currently low cation mobilization, while anion mobilization due to reductive Fe dissolution will remain high. Once acidic sediments further inland are flooded with seawater, highest contaminant mobilization can be expected as high salinity will further enhance already high cation mobilization under acidic pH. Long-term flooding with seawater will neutralize the sediment pH and limit cation mobilization compared to acidic pH. However, the contaminant load stored in the estuary is so high that, extrapolating data obtained, mobilization could last for >1000 years, e.g. for As, Pb, and Al.

High resolution mass spectrometric suspect screening, wide-scope target analysis of emerging contaminants and determination of legacy pollutants in adult black-tailed godwit Limosa limosa limosa in the Netherlands – A pilot study

The Dutch breeding population of the black-tailed godwit Limosa limosa limosa has declined substantially over recent decades; the role of contaminants is unknown. We analysed liver samples from 11 adult birds found dead on their breeding grounds in SW Friesland 2016–2020, six from extensive, herb-rich grasslands, five from intensive grasslands. We carried out LC and GC wide-scope target analysis of more than 2400 substances, LC suspect screening for more than 60,000 substances, target analysis for Cd, Hg, Ni and Pb, organo-phosphate flame retardants (OPFRs), dechlorane plus compounds and selected polybrominated diphenyl ether flame retardants (PBDEs), and bioassay for polybrominated dibenzo-p-dioxins and dibenzofurans (PBDDs/PDBFs) and dioxin-like polychlorinated biphenyls (dl-PCBs). Residues of 29 emerging contaminants (ECs) were determined through wide-scope target analysis. Another 20 were tentatively identified through suspect screening. These contaminants include industrial chemicals (personal care products, surfactants, PAHs and others), plant protection products (PPPs) and pharmaceuticals and their transformation products. Total contaminant load detected by wide-scope target analysis ranged from c. 155 to c. 1400 ng g−1 and was generally lower in birds from extensive grasslands. Heatmaps suggest that birds from intensive grasslands have a greater mix and higher residue concentrations of PPPs, while birds from extensive grasslands have a greater mix and higher residue concentrations of per- and polyfluoroalkyl substances (PFAS). All four metals and two OPFRs were detected. All tested PBDEs were below the respective LODs. Bioassay revealed presence of PBDDs, PBDFs and dl-PCBs. Further research is required to elucidate potential health risks to godwits and contaminant sources.

Early-life diet specificity is associated with long-lasting differences in apparent survival in a generalist predator.

Early-life conditions can have long-term fitness consequences. However, it is still unclear what optimal rearing conditions are, especially for long-lived carnivores. A more diverse diet ('balanced diet') might optimize nutrient availability and allow young to make experiences with a larger diversity of prey, whereas a narrow diet breadth ('specialized diet') might result in overall higher energy net gain. A diet that is dominated by a specific prey type (i.e. fish, 'prey type hypothesis') might be beneficial or detrimental, depending for example, on its toxicity or contaminant load. Generalist predators such as the white-tailed eagle Haliaeetus albicilla provide an interesting possibility to examine the relationship between early life diet and long-term offspring survival. In the Åland Islands, an archipelago in the Baltic Sea, white-tailed eagles live in various coastal habitats and feed on highly variable proportions of birds and fish. We use data from 21,116 prey individuals that were collected from 120 territories during the annual surveys, to examine how early-life diet is associated with apparent annual survival of 574 ringed and molecular-sexed eaglets. We supplement this analysis by assessing the relationships between diet, reproductive performance and nestling physical condition, to consider whether they are confounding with possible long-term associations. We find that early-life diet is associated with long-term fitness: Nestlings that are fed a diverse diet are in lower physical condition but have higher survival rates. Eagles that are fed more fish as nestlings have lower survival as breeding-age adults, but territories associated with fish-rich diets have higher breeding success. Our results show that young carnivores benefit from a high diversity of prey in their natal territory, either through a nutritional or learning benefit, explaining the higher survival rates. The strong relationship between early-life diet and adult survival suggests that early life shapes adult foraging decisions and that eating fish is associated with high costs. This could be due to high levels of contaminants or high competition for fish-rich territories. Long-lasting consequences of early-life diet are likely not only limited to individual-level consequences but have the potential to drive eco-evolutionary dynamics in this population.

Wastewater-Irrigated Vegetables Are a Significant Source of Heavy Metal Contaminants: Toxicity and Health Risks.

Water contaminated with heavy metals constitutes an important threat. This threat is a real problem with a negative impact in some developing countries where untreated industrial effluents are used for irrigation. The present study examines heavy metals in wastewater-irrigated vegetables (apple gourd, spinach, cauliflower, sponge gourd, and coriander) water, and soil from Chenab Nagar, Chiniot, Pakistan. In particular, the metals quantified were cadmium (Cd), chromium (Cr), cobalt (Co), nickel (Ni), lead (Pb), and manganese (Mn). Among them, Cr and Co in crops irrigated -wastewater exceeded the levels recommended by the World Health Organization (WHO). In contrast, Ni, Cu, Pb, and Mn concentrations were in line with WHO standards. Compared with the limits established by the Food and Agriculture Organization of the United Nations (FAO), all the study vegetables presented higher (thus unsafe) concentrations of Cd (0.38 to 1.205 mg/Kg). There were also unsafe concentrations of Cr in coriander, sponge gourd, and cauliflower. Pb was found at an unsafe concentration (0.59 mg/Kg) in cauliflower. Conversely, Ni and Mn concentrations were below the maximum permissible limits by WHO, and FAO in all of the analyzed samples. The contamination load index (CLI) in soil, bioconcentration factor (BCF) in plants, daily intake of metals (DIM), and health risk index (HRI) have also been evaluated to estimate the potential risk to human health in that area. We have found an important risk of transitions of Pb, Cd, Cr, and Co from water/soil to the edible part of the plant. The highest HRI value associated with Cd (6.10-13.85) followed by Cr (1.25-7.67) for all vegetable samples presented them as high health risk metal contaminants. If the issue is not addressed, consumption of wastewater-irrigated vegetables will continue posing a health risk.

Artisanal gold mine spoil types within a common geological area and their variations in contaminant loads and human health risks

This study answered the question of whether mine spoils occurring in a common geological location had similarities in their contaminant load and associated health risks. Using inductively coupled plasma mass spectrometry, the total contents of Cd, Pb, As, Hg, Zn, Fe, and Al were determined for 110 digested soil samples obtained from underground rock ore (URS), oxide ore (OXS), and alluvial ore (AVS) mine spoils. Independent sample Kruskal–Wallis test and pairwise comparisons of sources were used to ascertain the variation in elemental load between the mine spoil investigated. The results showed that mine spoil contaminations and their ecological and health risk significantly varied (p < 0.01) from each other and fell in the order OXS > URS > AVS > forest soils because of their geochemistry. Determined enrichment and geo-accumulation indices revealed that OXS and URS sites were severely–extremely polluted with Cd, Hg, and As, while AVS mine spoils were only moderately contaminated by Cd and As contents. Children had the highest tendency for developing noncarcinogenic health defects largely due to toxic contents of As, Cd, and Hg in soil materials near them than adult men and women would after obtaining a hazard index of 73.5 and 67.7 (unitless) at both OXS and URS sites. Mine spoils especially where hard rocks and oxide ores were processed are not fit for agricultural use or human habitation. The restriction of human access and sustainable remediation approaches are required to avert health defects. Even so, area-specific potentially toxic elements must be targeted during soil cleaning due to the significant variations in contaminant load between mined sites.

Absorption mechanism-based approach for synthesis of refinery desulfurization solvent network

Processing of sourer crude oil increases the desulfurization solvent circulation and energy consumption for solvent regeneration. In this work, synthesis of desulfurization solvent network based on mechanism model is proposed to overcome limitations of simplified models in traditional mass integration. A superstructure is presented for desulfurization solvent network where the input and the output of each desulfurization unit are correlated. Such a correlation is realized via an absorption mechanism model for methyldiethanolamine desulfurization. The mathematical models are formulated taking the desulfurization targets as constraints, instead of fixed flowrates, contaminant concentrations, or contaminant loads in traditional methods. A solution strategy combining stochastic and deterministic algorithms is proposed to solve the problems effectively. Finally, this approach is tested on a refinery case considering three scenarios. The solvent regeneration cost can be decreased by over 16.42%. Besides, the comparative results indicate that this mechanism-based method is more reliable than the traditional methods.

Use of male-to-female sex reversal as a welfare scoring system in the protandrous farmed gilthead sea bream (Sparus aurata).

Gilthead sea bream is a highly cultured marine fish throughout the Mediterranean area, but new and strict criteria of welfare are needed to assure that the intensification of production has no negative effects on animal farming. Most welfare indicators are specific to a given phase of the production cycle, but others such as the timing of puberty and/or sex reversal are of retrospective value. This is of particular relevance in the protandrous gilthead sea bream, in which the sex ratio is highly regulated at the nutritional level. Social and environmental factors (e.g., contaminant loads) also alter the sex ratio, but the contribution of the genetic component remains unclear. To assess this complex issue, five gilthead sea bream families representative of slow/intermediate/fast growth were grown out with control or a plant-based diet in a common garden system from early life to the completion of their sexual maturity in 3-year-old fish. The plant-based diet highly enhanced the male-to-female sex reversal. This occurred in parallel with the progressive impairment of growth performance, which was indicative of changes in nutrient requirements as the result of the different energy demands for growth and reproduction through development. The effect of a different nutritional and genetic background on the reproductive performance was also assessed by measurements of circulating levels of sex steroids during the two consecutive spawning seasons, varying plasma levels of 17β-estradiol (E2) and 11-ketotestosterone (11-KT) with age, gender, diet, and genetic background. Principal component analysis (PCA) of 3-year-old fish displayed a gradual increase of the E2/11-KT ratio from males to females with the improvement of nutritional/genetic background. Altogether, these results support the use of a reproductive tract scoring system for leading farmed fish toward their optimum welfare condition, contributing to improving the productivity of the current gilthead sea bream livestock.