Elevated Aluminum Concentrations Research Articles

Detection and Prediction of Toxic Aluminum Concentrations in High-Priority Salmon Rivers in Nova Scotia.

Elevated concentrations of toxic cationic aluminum (Ali) are symptomatic of terrestrial and freshwater acidification and are particularly toxic to salmonid fish species such as Atlantic salmon (Salmo salar). Speciated metal samples are rarely included in standard water monitoring protocols, and therefore the processes affecting Ali dynamics in freshwater remain poorly understood. Previous analysis of Ali concentrations in Nova Scotia (Canada) rivers found that the majority of study rivers had concentrations exceeding the threshold for aquatic health, but a wide-scale survey of Ali in Nova Scotia has not taken place since 2006 (Dennis, I. F., & Clair, T. A., 2012, Canadian Journal of Fisheries and Aquatic Sciences, 69(7), 1174-1183). The observed levels of dissolved aluminum in Atlantic salmon (Salmo salar) rivers of Atlantic Canada have potential serious and harmful effects for aquatic populations. We present the findings of the first large-scale assessment of the Ali status of Nova Scotia rivers in 17 years; we measured Ali concentrations and other water chemistry parameters at 150 sites throughout the Southern Uplands region of Nova Scotia from 2015 to 2022. We found that Ali concentrations exceeded toxic thresholds at least once during the study period at 80% of the study sites and that Ali concentrations increased during the study period at all four large-sample study sites. Modeling of relationships between Ali concentrations and other water chemistry parameters showed that the most important predictors of Ali are concentrations of the dissolved fractions of Al, iron, titanium, and calcium, as well as dissolved organic carbon and fluoride. We developed a fully Bayesian linear mixed model to predict Ali concentrations from a test data set within 15 μg/L. This model may be a valuable tool to predict Ali concentrations in rivers and to prioritize areas where Ali should be monitored. Environ Toxicol Chem 2024;00:1-12. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

A framework model to integrate sources and pathways in the assessment of river water pollution

Metal and nutrient pollution, soil erosion, and alterations in climate and hydrology are prevalent issues that impact the water quality of riverine systems. However, integrated approaches to assess and isolate causes and paths of river water pollution are scarce, especially in the case of watersheds impacted by multiple hazardous activities. Therefore, a framework model for investigating the multiple sources of river water pollution was developed. The chosen study area was the Paraopeba River basin located in the Minas Gerais, Brazil. Besides multiple agriculture, industrial, and urban pollution sources, this region was profoundly affected by the rupture of the B1 tailings dam (in January 2019) at the Córrego do Feijão mine, resulting in the release of metal-rich waste. Considering this situation, thirty-nine physicochemical and hydromorphological parameters were examined in the Paraopeba River basin, in the 2019–2023 period. The analysis involved various statistical techniques, including bivariate and multivariate methods such as correlation analysis, principal component analysis, and clustering. The Paraopeba River was mainly impacted by metal contamination resulting from the dam collapse, whereas nutrient contamination, mainly from urban and industrial discharges, predominantly affected its tributaries. Additionally, the elevated concentrations of aluminum, iron, nitrate, and sulfate in both main river and tributaries can be attributed to diffuse and point source pollution. In terms of hydromorphology and soil type, the interaction between woody vegetation and erosion-resistant soils, especially latosols, contributes to the stability of riverbanks in the main river. Meanwhile, in the tributaries, the presence of neosols and sparse vegetation in urbanized areas promoted riverbank erosion potentially amplifying pollution. While the study was conducted in a particular watershed, the findings are based on a methodology that can be applied universally. Hence, the insights on surface water quality from this research can be a valuable resource for researchers studying watersheds with diverse pollution sources.

Beneficial aluminium immobilizing microorganisms inhabiting the rhizosphere of pea

Acid soils contain elevated concentrations of mobile aluminium (Al) ions which are toxic for plants. Plants form symbioses with the rhizosphere microorganisms stimulating plant growth and affecting Al availability. Here, for the first time the approach based on the ability to immobilize Al in soil was applied for initial selection of beneficial rhizosphere microorganisms. Al-Immobilizing yeast Rhodotorula sp. AL1 and 12 bacterial strains assigned to various genera and species were isolated from the rhizosphere of pea cultivated in acid soils. Immobilization of Al was related to the increased pH of the environment and the formation of insoluble Al phosphates in soil. The strains differed in possessing beneficial properties such as modulation of the nutrient element (Ca, Fe, K, Mg, Mn, P) concentrations in soil, production of phytohormones (auxins, abscisic and gibberellic acids, ethylene), utilization of 1-aminocyclopropane-1-carboxylic acid and organic components typical for root exudates, acetylene reduction and antifungal activities. Eight strains promoted root elongation of radish seedlings by 30÷50 % with a maximal effect exerted by Cupriavidus basilensis strain D39. Taking together, the selected microorganisms are promising models to study the mechanisms of plant-microbe interactions in the presence of toxic Al and improving Al tolerance of plants in acid soils.

Using Zeolites to Cold Stabilize White Wines

Background and Aims. Tartrate stabilisation is a necessary step in commercial wine production. The traditional method to prevent crystallisation and precipitation of potassium bitartrate (KHT) after a wine is bottled is by adding seed KHT crystals to wine stored in a tank and holding temperatures below 0°C for a set period of time before bottling. This process requires time and energy and a filtration step to remove sediment. However, compared to other technical solutions such as reverse osmosis, electrodialysis, or ion exchange, it is still the most economical stabilisation option. This work aims to evaluate the ability of zeolites to cold stabilize white wines. Since zeolites can also remove proteins and thus heat-stabilize white wines, the new process can potentially combine heat and cold stability in a single treatment. Methods and Results. Effective tartrate stabilisation was achieved by mixing a natural zeolite sample with white wine for three hours. Although the quantum of required zeolite was larger than bentonite, zeolite did not exhibit shrink-swell behaviour, thus enabling greater wine recovery and capacity to be regenerated. Effective heat and cold stability could be achieved using a low-calcium zeolite as a processing aid in a single treatment. To avoid aluminium leaching and elevated aluminium concentrations in the treated wine, the zeolite was calcinated before being added to the wine. The calcination process also reduced calcium content in the wine after treatment with zeolite, thus eliminating the risk of calcium instability. Conclusions. The application of zeolite as a processing aid can potentially be effective in cold-stabilizing white wines and removing proteins responsible for haze formation. Significance of the study. Zeolites may constitute an alternative technology in white wine production facilitating heat and cold stabilisation in a single treatment.

Synoptic snapshots: monitoring lake water quality over 4 decades in an urbanizing region

Doucet C, Johnston L, Hiscock A, Bermarija T, Hammond M, Holmes B, Smith T, Lalonde B, Parent D, Deacoff C, Scott R, Kurek J, Jamieson R. 2023. Synoptic snapshots: monitoring lake water quality over 4 decades in an urbanizing region. Lake Reserv Manage. XX: XX–XXX. Synoptic water quality surveys—measuring major ions, nutrients, pH, organic matter, and trace elements—have been conducted in ∼50 lakes in the Halifax Regional Municipality (Nova Scotia, Canada) once per decade since 1980. In this study, lake water quality over 40 yr was examined and urban development was evaluated as a possible driver of observed changes. More than half of the lakes experienced strong (>50%) increases in conductivity, iron, sodium, chloride, calcium, and total phosphorus (TP), and strong decreases in acidity (i.e., [H+]). Between 20% and 50% of the lakes experienced strong increases in nitrate, alkalinity, zinc, color, aluminum, dissolved organic carbon, and magnesium, and strong decreases in manganese and sulfate. In 2021, national guidelines for the protection of aquatic life were exceeded by chloride, aluminum, manganese, and arsenic in certain lakes. Land cover classification from circa 1980 and 2020 revealed that although change in urban development within the lake watersheds ranged from a decrease of 11 percentage points to an increase of 48 percentage points, the majority (90%) of watersheds experienced an increase. Urban development was associated with increased chloride, conductivity, sodium, calcium, and TP concentrations. Other parameters appear to be more influenced by hydrology, watershed characteristics, climate, and decreased acid deposition. Results highlight emerging water quality concerns, such as elevated aluminum concentrations, and increased concentrations of chloride, nutrients, and arsenic, which should be the focus of strategic monitoring and mitigation efforts.

Distribution of Aluminium in the Water Supply System of Sofia City, Bulgaria

Elevated concentrations of aluminium have been found at the outlets of the Drinking Water Treatment Plants (DWTPs) of Sofia city, Bulgaria and in separate sampling points in the water supply network. Cluster analysis is performed for multivariate data interpretation of the distribution of aluminium (Al) concentrations during 2019 at 19 water sampling points (2 DWTPs outlets and 17 points within the city water supply system). Although the concentration of aluminium in the outlet of the treatment plants differ significantly, both of them fall into the same cluster, as the concentrations during the year change in the same manner. The formed cluster of both the treatment plants and most of the studied sampling points indicate the mixed origin of the purified water and proves that the concentration of Al in tap water is dominated by the qualities and quantities from the different sources of the supplied water, rather than by the secondary processes in the network for areas with predominant steel and polyethylene pipes. A distinct exception are the areas with old asbestos cement pipelines where potential release of the metal from the cement affects the Al distribution in the water supply system.

The effect of urinary essential and non-essential elements on serum albumin: Evidence from a community-based study of the elderly in Beijing.

Background & aimsFew epidemiological studies have investigated the relationships of urinary essential and non-essential elements with serum albumin, an indicator of nutritional status, especially for the elderly in China.MethodsA community-based study among elderly participants (n = 275) was conducted in Beijing from November to December 2016. We measured 15 urinary elements concentrations and serum albumin levels. Three statistical methods including the generalized linear model (GLM), quantile g-computation model (qgcomp) and bayesian kernel machine regression (BKMR) were adapted.ResultsIn GLM analysis, we observed decreased serum albumin levels associated with elevated urinary concentrations of aluminum, arsenic, barium, cobalt, chromium, copper, iron, manganese, selenium, strontium, and zinc. Compared with the lowest tertile, the highest tertile of cadmium and cesium was also negatively associated with serum albumin. Urinary selenium concentration had the most significant negative contribution (30.05%) in the qgcomp analysis. The negative correlations of element mixtures with serum albumin were also observed in BKMR analysis.ConclusionsOur findings suggested the negative associations of essential and non-essential elements with serum albumin among the elderly. Large-scare cohort studies among the general population are required to validate our findings and elucidate the relevant underlying mechanisms.

Выявление омик-маркеров негативных эффектов, ассоциированных с аэрогенным комбинированным воздействием соединений алюминия и фтора

At present, it is relevant to study simultaneous combined impacts exerted by chemicals on developing adverse health effects. It is also becoming vital to search for molecular indicators of adverse effects with the altered expression level. This alteration makes it possible to determine peculiarities of molecular and cellular pathogenesis mechanisms regarding a number of non-communicable diseases under exposure to a mixture of chemicals. Our research goal was to comparatively analyze and identify identical omic-markers of adverse effects under experimental and actual combined aerogenic exposure to aluminum and fluoride compounds. We substantiated molecular markers of prenosological changes by sequential implementation of an algorithm which included identifying altered proteins and peptides in blood plasma which were identical both under experimental and actual exposure; detecting and quantifying cause-effect relations between identical proteins and peptides and concentrations of aluminum and fluoride ion in urine. The research results indicate that long-term combined aerogenic exposure to aluminum and fluoride compounds in low average daily doses (0.0005 mg/(kgday) and 0.002 mg/(kg*day) accordingly) causes elevated concentrations of aluminum (by 2.8 times higher) and fluoride-ion (by 1.8 times higher) in exposed children’s urine. This fact is verified by experimental research with its focus on combined exposure to the examined chemicals. We were able to substantiate identical omic-markers, J-chain of immunoglobulin and Kelch-like protein 4 (KLHL4 gene), under simultaneous exposure to aluminum and fluoride compounds both under experimental and actual combined aerogenic exposure. We proved a cause-effect relation between levels of identical proteins and concentrations of aluminum and fluoride ion in urine under simultaneous exposure to the mixture of the examined chemicals. Identified protein markers in blood plasma give an opportunity to predict future adverse effects including developing immunoglobulins A and M deficiency with subsequent humoral immunity failure when J-chain of immunoglobulin is expressed; occurring sclerotic and inflammatory changes in vascular walls when Kelch-like protein 4 is expressed. These predicted adverse effects can be estimated as resulting from simple summated (additive) toxic impacts exerted by aluminum and fluoride under simultaneous combined aerogenic exposure to both chemicals.

On detecting omic-markers of negative effects associated with combined aerogenic exposure to aluminum and fluoride compounds

At present, it is relevant to study simultaneous combined impacts exerted by chemicals on developing adverse health effects. It is also becoming vital to search for molecular indicators of adverse effects with the altered expression level. This alteration makes it possible to determine peculiarities of molecular and cellular pathogenesis mechanisms regarding a number of non-communicable diseases under exposure to a mixture of chemicals. Our research goal was to comparatively analyze and identify identical omic-markers of adverse effects under experimental and actual combined aerogenic exposure to aluminum and fluoride compounds. We substantiated molecular markers of prenosological changes by sequential implementation of an algorithm which included identifying altered proteins and peptides in blood plasma which were identical both under experimental and actual exposure; detecting and quantifying cause-effect relations between identical proteins and peptides and concentrations of aluminum and fluoride ion in urine. The research results indicate that long-term combined aerogenic exposure to aluminum and fluoride compounds in low average daily doses (0.0005 mg/(kgday) and 0.002 mg/(kg*day) accordingly) causes elevated concentrations of aluminum (by 2.8 times higher) and fluoride-ion (by 1.8 times higher) in exposed children’s urine. This fact is verified by experimental research with its focus on combined exposure to the examined chemicals. We were able to substantiate identical omic-markers, J-chain of immunoglobulin and Kelch-like protein 4 (KLHL4 gene), under simultaneous exposure to aluminum and fluoride compounds both under experimental and actual combined aerogenic exposure. We proved a cause-effect relation between levels of identical proteins and concentrations of aluminum and fluoride ion in urine under simultaneous exposure to the mixture of the examined chemicals. Identified protein markers in blood plasma give an opportunity to predict future adverse effects including developing immunoglobulins A and M deficiency with subsequent humoral immunity failure when J-chain of immunoglobulin is expressed; occurring sclerotic and inflammatory changes in vascular walls when Kelch-like protein 4 is expressed. These predicted adverse effects can be estimated as resulting from simple summated (additive) toxic impacts exerted by aluminum and fluoride under simultaneous combined aerogenic exposure to both chemicals.

The price of persistence: Assessing the drivers and health implications of metal levels in indicator carnivores inhabiting an agriculturally fragmented landscape

Patterns and practices of agricultural expansion threaten the persistence of global biodiversity. Wildlife species surviving large-scale land use changes can be exposed to a suite of contaminants that may deleteriously impact their health. There is a paucity of data concerning the ecotoxicological impacts associated with the global palm oil (Elaeis guineensis) industry. We sampled wild Malay civets (Viverra tangalunga) across a patchwork landscape degraded by oil palm agriculture in Sabah, Malaysian Borneo. Using a non-lethal methodology, we quantified the levels of 13 essential and non-essential metals within the hair of this adaptable small carnivore. We robustly assessed the biological and environmental drivers of intrapopulation variation in measured levels. Metal concentrations were associated with civet age, weight, proximity to a tributary, and access to oxbow lakes. In a targeted case study, the hair metal profiles of 16 GPS-collared male civets with differing space use patterns were contrasted. Civets that entered oil palm plantations expressed elevated aluminium, cadmium, and lead, and lower mercury hair concentrations compared to civets that remained exclusively within the forest. Finally, we paired hair metal concentrations with 34 blood-based health markers to evaluate the possible sub-lethal physiological effects associated with varied hair metal levels. Our multi-facetted approach establishes these adaptable carnivores as indicator species within an extensively altered ecosystem, and provides critical and timely evidence for future studies.

Rapid recovery of normal gill morphology and blood physiology in brown trout (<em>Salmo trutta</em>) after short-term exposure to toxic concentrations of aqueous aluminium under non-steady state chemical conditions

Freshwater acidification is characterised by elevated concentrations of aqueous aluminium. Global emissions of acidifying agents are reduced due to international agreements, and freshwater acidification has shifted from chronic to a more episodic character. The recovery of fish populations in acidified areas is likely to depend on the individual’s ability to recover from short-time aluminium exposures. We exposed brown trout (Salmo trutta) to an Al-rich medium, nominal concentration 600 µg L–1, for 0.5, 2, 6, 8 and 11 hours, before transfer to circumneutral Al-poor water for recovery. As controls, fish were either exposed for 11 hours to an acidified Al-poor medium or to untreated water. Some mortality during the first 24 hours of the recovery period occurred in fish exposed for 11, 8 and 6 hours to aluminium. No mortality during recovery was observed in the remaining groups. Aluminium exposure led to increased haematocrit and plasma lactate concentration, decreased plasma chloride concentration, deposition of aluminium on gill surfaces, and morphological alteration of the gill structures. The responses depended on exposure time. Aluminium deposited on the gill disappeared and plasma lactate levels were at control levels after 1 day in the recovery water, while haematocrit and plasma chloride levels were at control levels after 14 days of recovery. Gills in fish exposed to aluminium for 11 hours were almost fully recovered after 14 days. We conclude that the toxic response in brown trout exposed to an acutely toxic aluminium challenge is reversible. Moreover, the first 24 hours after aluminium exposures is the most critical period for the fish recovery. Further, it takes no more than 14 days for brown trout to fully recover from an acute toxic aluminium exposure, and only 1 day if the aluminium challenge is moderate.

Statistical study of Khibiny Alkaline Massif (Kola Peninsula) groundwater quality with respect to elevated aluminum concentrations

ABSTRACT Current study addresses a problem of elevated aluminum concentrations deteriorating Khibiny Alkaline Massif groundwater quality. The application of chemometric methods to the field dataset 1999–2018 allows to quantitatively describe the groundwater quality, reveal variability patterns and potential sources of elevated aluminum level in the groundwater. The field dataset contains almost 40% more observations of 12 physicochemical groundwater quality parameters than the dataset analyzed in our previous studies on Khibiny groundwater quality assessment reported in the literature. The results revealed statistically significant (α-level=0.05) associations between Al and pH, Cl−, , according to the calculated matrix using distance correlation method. The mathematical models developed with the application of multiple regression and factor/principal component analysis elucidate up to 55.5% Al concentration variability and up to 68.3% of total dataset variance. Calculated for the 19-year period the water quality index values, which changed in early 2000s from fair to a marginal category, still belongs to this category reflecting unsatisfactory water quality conditions. Comparing the current study results to the conclusions drawn in our previous publications it is assumed that the main factors determining substandard groundwater quality have remained the same since last groundwater quality assessment reported in the literature. The examined combination of chemometric methods allows to gain insight into the main features of variability patterns of water quality characteristics and the potential sources of groundwater contamination. This approach forms a reliable foundation for enhancing groundwater quality monitoring and control in the Arctic region of interest and other locations experiencing similar problems.

Decade-scale change in testate amoebae community primarily driven by anthropogenic disturbance than natural change in a large subtropical reservoir

Understanding the extent of human activities leading to an influx of chemical pollutants that cause substantial environmental transformations is the focus of much ongoing research. In this study, we present a multi-proxy record based on a sediment core from a large subtropical reservoir (Xinfengjiang Reservoir) in south China with an emphasis on the changes in testate amoebae community, in combination with sedimentological (radioactivity, physicochemistry, nutrient and organochlorine pesticides) and climatological (air temperature and precipitation) data over the last three decades. Twenty-seven testate amoebae species belonging to seven genera (Arcella, Centropyxis, Cyclopyxis, Difflugia, Netzelia, Euglypha and Pseudodifflugia) were observed. Species richness, abundance and biomass of testate amoebae were in ranges of 18–26 species, 616–825 ind. ml−1 and 9.0–19.4 μg C ml−1, respectively. Two development stages of the reservoir, dated to 1978–1993 (stage 1) and 1993–2006 (stage 2), were distinguished based on testate amoebae communities. Stage 1 was characterized by elevated dry bulk density, carbon-to‑nitrogen ratio and p,p’-DDE in the sediment core and an impact of nitrogen and sulfur deficiency on testate amoebae. Stage 2 was marked by a decrease of dry bulk density, elevated concentrations of aluminum, iron and carbon, low carbon-to‑nitrogen ratio and organochlorine pesticides, fluctuations in rainfall on shorter and yearly timescales, and a stronger influence of the organochlorine pesticides on testate amoebae. Testate amoebae community change and the identified two-stage development were consistent with atmospheric deposition of organochlorine pesticides from anthropogenic sources inside and outside the reservoir watershed, nutrient influx and sediment physicochemistry. The testate amoebae community dynamics and a strong community-environment relationship in stage 2 were linked with non-random patterns in the biotic neighborhoods of species (deterministic processes). The results suggest a stronger impact of anthropogenic disturbance than natural environmental change on testate amoebae community variation of Xinfengjiang Reservoir over time.

Maternal metal concentration during gestation and pediatric morbidity in children: an exploratory analysis

BackgroundThe majority of studies linking exposure to metals with certain health outcomes focus on known toxic metals. Alternatively, this study assesses the extent to which exposure to a wider range of metals during gestation is associated with childhood morbidity.MethodsWe analyzed the concentrations of 25 metals found in urine samples of 111 pregnant women of Arab-Bedouin origin collected prior to birth. In addition, we collected medical records on their offspring for six years following birth, including every interaction with HMOs, local hospitals, and pharmacies.ResultsThe main types of morbidities diagnosed and treated during this period were preterm births, malformations, asthma-like morbidity, cardiovascular and behavioral problems, and obesity. Multivariable analysis showed that offspring born before term were more likely to have been exposed to elevated maternal concentrations of zinc, thallium, aluminum, manganese, and uranium, all with adjusted relative risk above 1.40 for an increase by each quintile. Likewise, children with asthma had been exposed to higher levels of magnesium, strontium, and barium at gestation, while behavioral outcomes were associated with elevated biometals, i.e., sodium, magnesium, calcium, selenium, and zinc, as well as higher levels of lithium, cobalt, nickel, strontium, cadmium, vanadium, arsenic, and molybdenum. A heatmap of adjusted relative risk estimates indicates the considerable implications that exposure to metals may have for preterm birth and developmental outcomes.ConclusionsThe current study shows that perinatal exposure to metals is adversely associated with pediatric morbidity. Further such analyses on additional samples are warranted.

Trace Element Concentrations Associated with Mid-Paleozoic Microfossils as Biosignatures to Aid in the Search for Life.

Identifying microbial fossils in the rock record is a difficult task because they are often simple in morphology and can be mimicked by non-biological structures. Biosignatures are essential for identifying putative fossils as being definitively biological in origin, but are often lacking due to geologic effects which can obscure or erase such signs. As such, there is a need for robust biosignature identification techniques. Here we show new evidence for the application of trace elements as biosignatures in microfossils. We found elevated concentrations of magnesium, aluminum, manganese, iron, and strontium colocalized with carbon and sulfur in microfossils from Drummond Basin, a mid-Paleozoic hot spring deposit in Australia. Our results also suggest that trace element sequestrations from modern hot spring deposits persist through substantial host rock alteration. Because some of the oldest fossils on Earth are found in hot spring deposits and ancient hot spring deposits are also thought to occur on Mars, this biosignature technique may be utilized as a valuable tool to aid in the search for extraterrestrial life.

Evaluation of Dialysis Water Quality at Hospitals in Baghdad, Iraq.

Background.Dialysis water quality is one of the most important factors for ensuring the safe and effective delivery of hemodialysis. It has been known for over a decade that there might be hazardous contaminants in the water and concentrates used to prepare dialysis fluid. Rigorous international standards for the purification of dialysis fluids have been established, which were used in the present study to compare the quality of dialysis water as there is no national standard for dialysis water quality in Iraq.Objectives.There are more than 20 dialysis centers in Iraq, most of which contain similar units for the processing of dialysis water. The present study evaluated the quality of water used for dialysis in four dialysis centers located within Baghdad hospitals.Methods.Physical and chemical tests were carried out in the laboratory after sampling water from each dialysis center. Water samples were collected from three locations in each dialysis center. Hospital municipal water samples were collected from the tanks feeding dialysis units; samples of dialysis water were collected from the dialysis water treatment unit outlets; and samples of dialysis water were collected from the distribution network in dialysis rooms.Results.The results showed a fluctuation in the quality of the dialysis water (dialysis water and water from the dialysis distribution network), indicating that it is unacceptable compared to international standards. Chemical analysis showed that 75% of the dialysis water had elevated aluminum concentrations. Chemical analysis also found that dialysis water had elevated concentrations of free residual chlorine at some dialysis centers.Conclusions.All hemodialysis centers need careful monitoring and preventive maintenance to ensure good water quality. In addition, it is important to revise the design of the water treatment units according to water quality.Competing Interests.The authors declare no competing financial interests

Ionic aluminium concentrations exceed thresholds for aquatic health in Nova Scotian rivers, even during conditions of high dissolved organic carbon and low flow

Abstract. Acid deposition released large amounts of aluminium into streams and lakes during the last century in northern Europe and eastern North America. Elevated aluminium concentrations caused major environmental concern due to aluminium's toxicity to terrestrial and aquatic organisms and led to the extirpation of wild Atlantic salmon populations. Air pollution reduction legislation that began in the 1990s in North America and Europe successfully reduced acid deposition, and the aluminium problem was widely considered solved. However, accumulating evidence indicates that freshwater systems still show delays in recovery from acidification, with poorly understood implications for aluminium concentrations. Here, we investigate spatial and temporal patterns of labile cationic forms of aluminium (Ali) from 2015 to 2018 in 10 catchments in Nova Scotia, Canada; this region was one of the hardest hit by acid deposition, although it was not considered to have an aluminium problem due to its high dissolved organic carbon (DOC) concentrations that were expected to reduce Ali concentrations. Surprisingly, our results show the widespread and frequent occurrences of Ali concentrations that exceed toxic thresholds in all sampled rivers despite high DOC concentrations. Generalized linear mixed model results reveal that DOC, instead of being inversely related to Ali, is the strongest predictor (positive) of Ali concentrations, suggesting that the recruitment properties of DOC in soils outweigh its protective properties in streams. Lastly, we find that, contrary to the common conceptualization that high Ali levels are associated with storm flow, high Ali concentrations are found during base flow. Our results demonstrate that elevated Ali concentrations in Nova Scotia continue to pose a threat to aquatic organisms, such as the biologically, economically, and culturally significant Atlantic salmon (Salmo salar).

Removal of aluminum from alkaline aqueous solution by adsorption on Degussa P25 TiO2 and vermiculite concrete‐supported ferric oxyhydroxide

AbstractThe current investigation on aluminum adsorption from an aqueous solution originated from the need to implement a water treatment technology that would decrease the prohibitive aluminum concentrations in the groundwater of the Khibiny Alkaline Massif (Kola Peninsula), which is limiting the use of this water source as a source for the household water supply in the area. TiO2 and vermiculite concrete‐supported ferric oxyhydroxide (VC) were used as adsorbents to remove aluminum from the alkaline aqueous solution, considering the water‐specific natural conditions of the Khibiny aquifer. The effects of pH, initial aluminum concentration, contact time, adsorbent dose, and ions present in Khibiny groundwater were investigated. The results showed that the adsorption kinetics followed the pseudo‐second order model, and the equilibrium data were described well by Langmuir and Freundlich isotherm models. The aluminum adsorption on TiO2 exhibited a dramatically higher adsorption rate compared to VC; the adsorption equilibrium was reached in 30 and 240 minutes, respectively, while the maximum TiO2 and VC adsorption capacities were similar and had values of 6.85 and 6.75 mg g−1 as the results of laboratory tests revealed. It was shown that when these two adsorbents worked jointly the capacity reached 8.28 mg g−1 within 60 minutes at pH 9.0. No apparent significant effects on aluminum removal by adsorbents tested in the presence of SO42−, NO3−, and Cl− were observed. The obtained outcomes identify a possible approach and reliable foundation for water treatment technology to solve the problem of elevated aluminum concentrations in the household water of the Khibiny Alkaline Massif area as well as within other locations where the solution of this problem can improve living conditions or industrial technologies.

Assessment of Khibiny Alkaline Massif groundwater quality using statistical methods and water quality index

AbstractGroundwater is a major source for the water supply of households in the mining‐intensive area of Khibiny Alkaline Massif, Kola Peninsula, in the Arctic. There are an increasing number of signs of groundwater quality deterioration in the area caused by the presence of elevated aluminum concentrations. Groundwater quality studies using univariate and multivariate statistical methods and the Water Quality Index were conducted to analyze a field dataset including 12 groundwater quality parameters monitored between 1999 and 2012. Descriptive statistics showed that the monitored water did not meet the established drinking water standards for aluminum concentration and pH level. The calculated Spearman correlation coefficient matrix revealed statistically significant associations (α‐level = .05) between Al concentrations and pH values, concentrations of SO42−, NO3−, Cl−, and TDS. Factor analysis using the principal component analysis extraction method (FA/PCA) identified four major influencing factors. Altogether the factors captured 67.53% of the dataset total variance. The outcomes of the hierarchical cluster analysis (HCA) revealed that the 12 monitored groundwater quality parameters can be grouped into three clusters where the concentration of Al and pH level formed a separate cluster. The calculated score values of the Canadian Council of Ministers of the Environment Water Quality Index indicated a deterioration of groundwater quality over the monitoring period.

Aluminum in infant formulas commercialized in Brazil: Occurrence and exposure assessment

Considering the immaturity of babies’ gastrointestinal system, particularly those of newborn infants, elevated aluminum (Al) concentrations can be toxic, and exposure to this contaminant due to the substitution of breast milk by infant formulae may represent a risk. The main sources of Al contamination in these products include the variability in the raw material (milk or soy), the formula composition, the contamination during processing and the presence of additives or mineral supplements. However, there are few recent reports in the literature on the occurrence of Al in milk-based or soy-based infant formulae. Thus, the aim of the present work was to study the presence of Al in samples of infant formulae acquired on the local market in Campinas, Sao Paulo, Brazil and estimate children exposure to this element. The Al contents were determined using optical emission spectrometry with an inductively coupled plasma source. The results obtained presented maximum values of 1.46, 5.94 and 4.49 mg kg−1 for starter, follow-up and specialized formulae, respectively. As from these data, it was estimated that the consumption of infant formulae (0–6 months) could reach 22.4% of the Al tolerable weekly intake (TWI), whereas a maximum value of 29.4% was observed for children between 12–24 months. The results obtained in this study show that the Al levels in infant formulae could suggest a potential concern for infants, and should therefore be monitored.