Aluminium in tea—concentrations, speciation and bioavailability

Do You Know What You Drink? Comparative Research on the Contents of Radioisotopes and Heavy Metals in Different Types of Tea from Various Parts of the World

The aim of this study was to assess the potential health risks of radioactive elements and heavy metals ingested through the consumption of various types of tea imported to the Polish market (black, green, red, oolong and white). The concentrations [Bq/kg] of radionuclides (40K, 137Cs, 226Ra, 210Pb and 228Th) in tea leaves before and after brewing were measured using γ-ray spectrometry with high-purity germanium (HPGe). The concentrations [mg/kg] of the studied elements (Fe, Cr, Cu, Mo, Al, Mn, Ni, P, V, Cd and Pb) were determined using a microwave-induced plasma optical emission spectrometer (MIP-OES). The results presented here will help to expand the database of heavy metals and radioactivity in teas. With regard to the potential health risk, the percentage of leaching of individual elements in different types of tea infusions was determined, and the assessment of the consumption risk was estimated. Since the calculated exposure factors, namely the HQ (Hazard Quotient) and THQ (Target Hazard Quotient), do not exceed critical levels, teas can still be considered health-beneficial products (most of the radionuclides as well as elements remain in the leaves (65-80%) after brewing).

Fluoride and Aluminium in Tea (Camellia sinensis L.)-Tea Quality Indicators and Risk Factors for Consumers

In recent years, the quality and sourcing of tea have gained importance in Europe, but information remains scarce. The aim of this study was to determine the concentrations of fluoride (F-) and total aluminium (Al) species in infusions of commercially available teas in Slovenia, and thus in Europe, and to relate them to tea quality and their impact on consumer safety. F- concentrations were determined using a fluoride-ion-selective electrode and Al concentrations using inductively coupled plasma optical emission spectroscopy. A comparison of the results obtained for four selected tea samples using the calibration curve and a standard addition technique showed good agreement, with no interferences caused by the sample matrix. The concentrations of 35 commercial teas ranged from 0.34 to 4.79 and 0.51 to 8.90 mg/L for F- and Al, respectively. The average concentrations of the two elements followed the same descending order: black filter > green filter > black leaves ≈ green leaves. Single and multivariate statistical methods supported the categorisation of teas by packaging but not by type, with tea in filter bags being more expensive than loose tea. The linear relationship between F- and Al concentrations in infusions (C(Al) = 1.2134 · C(F-)) allows for the determination of one element and estimation of the other, leading to a significant reduction in laboratory effort and cost. This research advances tea assessment by proposing Al concentration alongside F- as a quality indicator and provides the basis for tea-monitoring protocols. Finally, the daily consumption of larger quantities of tea (≈1 L) with elevated F- and Al concentrations could potentially pose a health risk.

Assessing transfer of aluminum during tea brewing and associated population health risks

Tea is consumed widely around the world owing to its refreshing taste and potential health benefits. However, drinking tea is considered a major route for dietary aluminum exposure in areas where tea consumption is relatively large. To assess the health risk associated with drinking tea, the contamination level of aluminum was determined in 81 tea samples. The transfer rate of aluminum during tea brewing was investigated. Then based on the site-specific exposure parameters such as consumption data and body weight for six different subpopulations in Fujian, the exposure risks were estimated using a probabilistic approach. Results demonstrate that the contents of aluminum in green tea, white tea, oolong tea, and black tea were significantly different according to the one-way ANOVA analysis (p < 0.05). The transfer rate of aluminum were 32.6%, 31.6%, 26.3%, and 14% for white tea, black tea, oolong tea, and green tea, respectively. With respect to the oral reference dose, the exposure of inhabitants in Fujian to aluminum through drinking tea is under control (even at the 99th percentile).

Essential and Potentially Toxic Elements (PTEs) Content in European Tea (Camellia sinensis) Leaves: Risk Assessment for Consumers

Tea (Camellia sinensis) is the second most consumed beverage worldwide, playing a key role in the human diet. Tea is considered a healthy drink, as its consumption has been linked to a lower risk of cardiovascular disease-related events and death, stroke, metabolic syndrome and obesity. However, several studies have shown that C. sinensis is a hyperaccumulator of Al and other elements that are considered potentially toxic. In the present study, the contents of 15 elements (both essential and toxic) were determined for the first time in tea leaves collected in tea gardens located in six different European countries and processed to provide black and green tea. The results showed that Al was the major toxic element detected, followed by Ni, Cr, Pb, As, Cd, Ag, and Hg. Essential elements were detected in the order of Mn, Fe, Zn, Cu, Co, and Se. Statistically significant correlations (p < 0.05) were found in the distribution of some elements, highlighting mechanisms of synergic or antagonist interaction. Multivariate analysis revealed that geographical origin was the main driver in clustering the samples, while the different treatment processes (black or green) did not significantly affect the contents of elements in the leaves. The estimation of potential non-carcinogenic risk revealed no risk for the consumption of European teas for consumers in terms of potentially toxic elements.

Impact of Litsea cubeba inter-row cover on the structure of bacterial community in the tea plantation

Purpose

The application of bio-control plants in the agricultural processes is one of the effective ways to solve the traditional agricultural synthetic pesticide residues. This study will investigate the effect of bio-control plant Litsea cubeba branch inter-row cover on soil bacterial community, soil-enriched metabolites, and soil mineral nutrition in tea plantation, which will provide a basis for the use of bio-control plant in agroecological farming systems.

Methods

The fruit-bearing (F-Pr) and vegetative (F-Ab) branches of Litsea cubeba were inter-row covered (the use of plants for partial coverage of soil between the rows) in the tea plantation. And we determined the soil microbial community, soil mineral nutriment, and soil-enriched metabolites composition with the methods of 16S rRNA gene sequencing, inductively coupled plasma-atomic emission spectroscopy (ICP-AEC), inductively coupled plasma-optical emission spectrometry (ICP-OES), and gas chromatography-mass spectrometry (GS-MS). We also predict the function of soil bacteria with the Tax4Fun software.

Results

Litsea cubeba inter-row cover modified the soil microbial structure and diversity; Litsea cubeba inter-row cover significantly decreased the relative abundance of Acidobacteria, Chloroflexi, and Planctomycetes while increased the relative abundance of Proteobacteria. Litsea cubeba inter-row cover significantly antagonized the plant pathogen community, and its OTUs number decreased from 907 ± 81 in the control to 337 ± 25 in F-Pr treatment; compared with F-Pr treatment, F-Ab treatment had weaker effect on the abundance of nutrition metabolism and transport, carbohydrate utilization, and nitrate reduction A. The aluminum element in the F-Pr treatment was significantly reduced, while phosphorus was increased. The soil-enriched metabolites of F-Pr treatment contained some antibacterial substance, including 14.2 ± 3.32% citronellol, 10.38 ± 4.79% alpha-terpineol, and 8.25 ± 2.62% (+)-2-bornanone, which was the main environment factor that affects the soil bacterial structure and diversity.

Conclusion

Litsea cubeba inter-row cover significantly affected bacterial structure and diversity, slightly increased the soil pH, and improved soil aluminum and phosphorus status; soil-enriched metabolites were the major environment factor affecting soil bacterial community and should be considered in the application of bio-control plants; Litsea cubeba vegetative branch inter-row cover will be a feasible measure for integrated pest management in tea plantation.

Potential Health Risk of Aluminum in Four Camellia sinensis Cultivars and Its Content as a Function of Leaf Position

Tea plants can accumulate aluminum (Al) in their leaves to a greater extent than most other edible plants. Few studies, however, address the Al concentration in leaves at different positions, which is important information for tea quality control. Leaves from four different cultivars of Camellia sinensis L. grown in Hawaii were analyzed for Al concentrations at 10 different leaf positions. Each cultivar was harvested in the winter and summer to determine seasonal variations of Al concentrations in the leaves. The results showed that Al concentrations in the winter leaves were an average of 1.2-fold higher than those in the summer leaves, although the seasonal variations were not statistically significant. The total Al concentration of successively lower leaves showed an exponential increase (R² ≥ 0.900) for all four cultivars in the summer season, whereas those of the winter leaves fit a bi-phase linear regression (R² ≥ 0.968). The regression of the Al concentrations against the top-5 leaf positions in the winter season fit one linear regression, while that against leaf positions 6-11 fit another linear regression. The average Al concentrations between the third leaf and the shoot plus first two leaves increased approximately 2.7-fold and 1.9-fold for all cultivars in the winter and summer months, respectively. The Al concentrations in the rest of the leaves increased approximately 1.5-fold in a sequential order. The target hazard quotient being between 1.69 × 10^-2 and 5.06 × 10^-1 in the tea leaf samples of the four cultivars in Hawaii were all less than 1, suggesting negligible health risks for consumers. The results of this study may be useful for directing harvest practices and estimating tea quality.

Elemental Composition of Commercial Herbal Tea Plants and Respective Infusions

This study evaluated the elemental composition of 25 herbal tea plants commonly used in infusions by Portuguese consumers and the contribution to the elemental daily intake of some essential elements. Hydrocotyle asiatica (L.), Matricaria chamomilla (L.), and Melissa officinalis (L.) samples are a rich source of K with around 6.0 mg g−1 while the Asteraceae Silybum marianum (L.) and Echinacea angustifolia (DC.) exhibited 4.9 and 5.6 mg g−1 Ca, respectively. The highest concentrations of S and Zn were noted in Hydrocotyle asiatica (L.), while the highest concentration of Sr was found in Cassia angustifolia (Vahl.). In general, a large variability in the concentrations among different families and plant organs had been observed, except Cu with levels around 30 μg g−1. The principal component analysis (PCA) showed positive correlations between Zn and S and Sr and Ca, also revealing that Hydrocotyle asiatica (L.), Echinacea angustifolia (DC.), Silybum marianum (L.), and Cassia angustifolia (Vahl.) samples, stands out about all other samples regarding the enrichment of macro and micronutrients. The elemental solubility of macronutrients in the infusion is greater than the micronutrient solubility, despite the contribution to the recommended daily intake was weak. As a whole, Cynara scolymus (L.) and Hibiscus sabdariffa (L.) are the species with the best elemental solubilities, followed by Hydrocotyle asiatica (L.). No harmful elements, such as As and Pb, were observed in both the raw material and the infusions.

Tease out the future: How tea research might enable crop breeding for acid soil tolerance

Unlike most crops, in which soil acidity severely limits productivity, tea (Camellia sinensis) actually prefers acid soils (pH 4.0-5.5). Specifically, tea is very tolerant of acidity-promoted aluminum (Al) toxicity, a major factor that limits the yield of most other crops, and it even requires Al for optimum growth. Understanding tea Al tolerance and Al-stimulatory mechanisms could therefore be fundamental for the future development of crops adapted to acid soils. Here, we summarize the Al-tolerance mechanisms of tea plants, propose possible mechanistic explanations for the stimulation of tea growth by Al based on recent research, and put forward ideas for future crop breeding for acid soils.

Aluminum in Coffee

This study investigated the aluminum content in one of the most consumed daily beverages: coffee. The total Al concentration in 10 different samples of coffee beans and their water-extractable fraction were determined. We then tested the influence of different brewing methods on the concentration of the extracted Al in the final beverage. Metal analyses were performed using graphite furnace atomic absorption spectroscopy (GF-AAS) after microwave-assisted acid digestion. The results showed highly variable Al contents in coffee beans (1.5-15.5 mg kg^-1), of which ∼2-10% were water-extractable. The brewing technique had a major influence on the Al content in the beverage: significantly higher Al concentrations (72.57 ± 23.96 μg L^-1) occurred in coffee brewed in an aluminum moka pot. Interestingly, using ground coffee with this method even reduced the Al content in the final beverage compared to the brewing water used. Coffee brewed from Al capsules did not contain significantly higher Al concentrations compared to other methods.

Simplified Method of Multi-Elemental Analysis of Dialyzable Fraction of Tea Infusions by FAAS and ICP OES

A fast and straightforward sample preparation procedure of the dialyzable fraction of infusions of teas prior to their analysis on Al, Ba, Ca, Cu, Fe, Mg, Mn, Ni, Sr, and Zn contents by flame atomic absorption spectrometry (FAAS) and inductively coupled plasma optical emission spectrometry (ICP OES) was developed and validated. The proposed methodology was based on acidification with HNO3 only and demonstrated good analytical performance, i.e., precision (0.80-5.0%), accuracy (< 5%), recoveries of elements (97.4-105%), and their detection limits (0.075-1.1 μg L-1) along with linearity of calibration curves in the whole studied concentration ranges. Applicability of the evaluated procedure, being a useful alternative to time-consuming wet digestions, was tested by determining bioaccessibility of elements in 20 infusions of black (BT) and green (GT) teas as assessed with the aid of in vitro gastrointestinal digestion. Average contributions of bioaccessible fractions (%) of studied metals were as follows: 1.18 (Al)-40.7% (Ca) and 4.65% (Al)-46.3% (Ca) for BTs and GTs, respectively. Drinking daily four cups (1 L) of tea, recommended dietary intakes (RDIs) of Ca, Cu, Fe, Mg, and Zn were covered to a small degree (< 1.5%). Only bioaccessibility of Mn highly contributed to RDI for this metal. According to provisional tolerable weekly intakes (PTWIs) for toxic elements such as Al and Ni, consumption of both types of teas should not represent any health risk. Additionally, analysis of variance of results clearly indicated that BTs and GTs were mostly differentiated due to concentrations of the bioaccessible fraction of Al, Ba, Cu, and Ni.

Aluminium toxicosis: a review of toxic actions and effects

Aluminium (Al) is frequently accessible to animal and human populations to the extent that intoxications may occur. Intake of Al is by inhalation of aerosols or particles, ingestion of food, water and medicaments, skin contact, vaccination, dialysis and infusions. Toxic actions of Al induce oxidative stress, immunologic alterations, genotoxicity, pro-inflammatory effect, peptide denaturation or transformation, enzymatic dysfunction, metabolic derangement, amyloidogenesis, membrane perturbation, iron dyshomeostasis, apoptosis, necrosis and dysplasia. The pathological conditions associated with Al toxicosis are desquamative interstitial pneumonia, pulmonary alveolar proteinosis, granulomas, granulomatosis and fibrosis, toxic myocarditis, thrombosis and ischemic stroke, granulomatous enteritis, Crohn's disease, inflammatory bowel diseases, anemia, Alzheimer's disease, dementia, sclerosis, autism, macrophagic myofasciitis, osteomalacia, oligospermia and infertility, hepatorenal disease, breast cancer and cyst, pancreatitis, pancreatic necrosis and diabetes mellitus. The review provides a broad overview of Al toxicosis as a background for sustained investigations of the toxicology of Al compounds of public health importance.

Fortification of Ground Roasted Coffees with Iron, Zinc, and Calcium Salts: Evaluation of Minerals Recovery in Filtered and Espresso Brews

Micronutrient deficiencies are of great public health and socioeconomic importance. Food fortification has been widely used as a simple low-cost resource to increase mineral intake. Considering that coffee is the most consumed food product worldwide, in this study, C. arabica and C. canephora seeds were roasted, ground, and fortified with three salts of iron, zinc, and calcium as part of the selection of appropriate mineral vehicles for fortification. After ranking the performance through a test by a trained tasters’ panel, only two salts for each mineral remained. Mineral recoveries were evaluated by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) in filtered (paper and nylon filters) and espresso brews. The best mean recoveries for each mineral in espresso brew prepared from fortified coffees were: 80.8% of iron as ferrous bisglycinate chelate, 75.4% of zinc as zinc lactate, and 72.1% of calcium as calcium lactate. These better ranked salts by the tasters’ panel. In filtered brews, mean recovery values of 51.1%, 47.6%, and 51.6% were obtained for the same mineral salts, respectively. No difference or very small differences were observed between species and types of filter. The results implications are discussed.

Ubiquitous aluminium contamination in water and amyloid hybrid membranes as a sustainable possible solution

We develop a membrane technology based on amyloid fibrils to remove aluminium from water and minimize its exposure to humans.

Voltammetric determination of aluminum(III) as Al-Alizarin S complex in tea leaves and infusions

This work presents, for the first time, DPV methodology of indirect aluminum (III) determination in tea leaves and infusions using the renewable silver amalgam electrode. A self-referencing strategy was proposed which relies on alternate voltammetric curves registration with and without conditioning of the electrode surface. The developed procedure utilizing formation of aluminum-Alizarin S complex shows linearity in the range of 2-50 μg L^-1 of Al(III) concentration, with r > 0.997. In the case of the electrode conditioning LOD is 0.2 μgL^-1 and repeatability expressed by CV is 1-2%. Introducing an additional operation i.e. electrode activation results in decrease of sensitivity from 0.0162 to 0.0043 μA/μgL^-1. The method was verified using CRM (tea leaves). Due to the wide variety of tea origin, types and producers, four most popular sorts (black, green, red and white) were chosen, made by one manufacturer. It was demonstrated that the proposed methodology may be applied in Al(III) determination in tea leaves and infusions. Al(III) extraction effectiveness was also examined. It was verified, that lemon juice addition during brewing increases aluminum concentration in infusions. Using Principal Components Analysis it was demonstrated that automatic distinction of infusions brewed with and without lemon juice, based on unprocessed voltammetric signal, may be successfully realized.

Formation and risk assessment of trihalomethanes through different tea brewing habits

Trihalomethanes (THMs) are suspected carcinogens and reproductive toxicants commonly found in chlorinated drinking water. This study investigates the formation of THMs and their associated risks during different tea brewing habits. Three main categories of tea (black, oolong, and green) under various brewing conditions and drinking water sources were tested. Tea samples prepared in ordinary thermos flask formed significant levels of total THM (TTHM). The highest TTHM formation came from black tea made with tap water, plausibly due to higher concentrations of reactive THM precursors. Compared with tap water, when the background solution is bottled water or distilled water, less TTHM was observed in prepared tea infusions. The results also revealed that unlike the traditional teapot-based tea serving habit, the removal of THMs is significantly reduced when tea infusion is stored in enclosed containers. Risk assessment analysis based on the survey among tea shop costumers also revealed that cancer risks induced by ingestion of THMs through drinking tea infusions prepared in thermos flask exceeded the tolerable level. Data obtained in this research demonstrated that drinking tea infusions directly from enclosed containers can be a significant source of exposure to THMs.

Comparison of total ionic strength adjustment buffers III and IV in the measurement of fluoride concentration of teas

Background:

Tea is the second most consumed drink in the UK and a primary source of hydration; it is an important source of dietary fluoride (F) for consumers and also abundant in aluminium (Al). Varying ranges of F concentrations in teas have been reported worldwide which may be, in part, due to differences in analytical techniques used to measure this ion.

Aim:

The effect of using total ionic adjustment buffers (TISAB) III or IV when measuring F concentration of black teas available in the UK was investigated and compared. Based on this evaluation, the effects of three different infusion times, 1 min, 10 min and 1 h, caffeine content and tea form on the F contents of the tea samples were investigated.

Methods:

The F concentrations of 47 tea samples were measured directly using a fluoride ion-selective electrode (F-ISE), TISAB III and IV and infusion times of 1 min, 10 min and 1 h.

Results:

Mean (SD) F concentration of tea samples for all infusion times was statistically significantly higher (p < 0.001) measured by TISAB IV (4.37 (2.16) mg/l) compared with TISAB III (3.54 (1.65) mg/l). A statistically significant positive correlation (p < 0.001) was found between Al concentration (mg/l) and differences in F concentration (mg/l) measured using the two TISABs; the difference in F concentration measured by the two TISABs increased with the magnitude of Al concentration.

Conclusion:

Due to higher concentrations of F and Al in teas and their complexing potential, use of TISAB IV facilitates more accurate measurement of F concentration when using an F-ISE and a direct method.

Aluminum and Heavy Metal Accumulation in Tea Leaves: An Interplay of Environmental and Plant Factors and an Assessment of Exposure Risks to Consumers

Environmental and plant factors (soil condition, variety, season, and maturity) and exposure risks of aluminum (Al), manganese (Mn), lead (Pb), cadmium (Cd), and copper (Cu) in tea leaves were investigated. The concentrations of these metals in tea leaves could not be predicted by their total concentrations in the soil. During any one season, there were differences in Al, Mn, and Cd levels between tea varieties. Seasonally, autumn tea and/or summer tea had far higher levels of Al, Mn, Pb, and Cd than did spring tea. Tea leaf maturity positively correlated with the concentrations of Al, Mn, Pb, and Cd, but negatively with Cu. The calculated average daily intake doses (mg/ [kg•d]) for these metal elements were 0.14 (Al), 0.11 (Mn), 2.70 × 10^-3 (Cu), 2.80 × 10^-4 (Pb), and 2.88 × 10^-6 (Cd). The hazard quotient values of each metal were all significantly lower than risk level (=1), suggesting that, for the general population, consumption of tea does not result in the intake of excessive amounts of Al, Mn, Pb, Cd, or Cu. This study identified the factors that can be monitored in the field to decrease consumer exposure to Al and Mn through tea consumption.

PRACTICAL APPLICATION

Environmental and plant factors influence aluminum and heavy metal accumulation in tea leaves. Consumers of tea are not ingesting excessive Al, Mn, Pb, Cd, or Cu. Trackable factors were identified to manage exposure levels.

Alteration of trace element concentrations in plants by adhering particles - Methods of correction

Trace element concentrations in plants may be influenced by airborne dust or adhering soil particles. Neglecting adhering particles in plant tissue leads to misinterpretation of trace element concentrations in research fields such as phytomining, phytoremediation, bio-monitoring, uptake of micronutrients and provenance studies. In case washing or brushing the samples prior to analysis is insufficient or impossible due to fragile or pre-processed samples mathematical correction should be applied. In this study three methods are presented allowing to subtract the influence of adhering particles in order to obtain the element concentrations in plants resulting only from uptake. All mathematical models are based on trace elements with negligible soil to plant transfer. A prerequisite for the correction methods is trace element analytics with good accuracy and high precision, e.g. through complete acid digestion. In a data set of 1040 plant samples grown in open field and pot trials most plants show a small but detectable amount of adhering particles. While concentrations of nutrients are nearly unaffected trace element concentrations such as Al, Cd, Co, Cr, Fe, Mn, Ni, Pb, REEs, Ti and U may be significantly altered. Different sampling techniques like cutting height can also significantly alter the concentrations measured in the samples.

A Green Sequential Injection Spectrophotometric Approach Using Natural Reagent Extracts from Heartwood of Ceasalpinia sappan Linn. for Determination of Aluminium

A cost-effective and environmentally friendly approach using a simple sequential injection spectrophotometric system with a non-synthetic reagent from plant extracts was proposed for a green analytical-chemistry methodology. The crude aqueous extracts from heartwood of Ceasalpinia sappan Linn. in acetate buffer pH 5.5 were utilized as an alternative natural reagent for the quantification of aluminium. The extracts contained homoisoflavonoid compounds, brazilin, and brazilein, which reacted with Al(3+) to form reddish complexes with the maximum absorption wavelength at 530 nm. The optimum conditions for the sequential injection parameters, such as sequential profile, sample and reagent volumes, and the pH effect, were investigated. Under the optimum conditions, a linear calibration graph in the range of 0.075 - 1.0 mg L(-1) Al(3+) was obtained with limits of detection and quantification of 0.021 and 0.072 mg L(-1) Al(3+), respectively. Relative standard deviations of 3.2 and 2.4% for 0.1 and 0.25 mg L(-1) Al(3+) (n = 11), respectively, and sampling rate of 128 injections h(-1) were achieved. The developed system was successfully applied to pharmaceutical preparations, water, and beverage samples. The results agreed well with those obtained from the ICP-AES method. Good recoveries between 87 and 104% were obtained.

In Vitro Digestibility of Aluminum from Hibiscus sabdariffa Hot Watery Infusion and Its Concentration in Urine of Healthy Individuals

Increased ingestion of aluminum (Al) can lead to its accumulation in the human body, especially in people with kidney problems. Al is also associated with several nervous diseases and its negative influence on embryo development during pregnancy has been proven in animal models. Hibiscus sabdariffa L. petals are widely used alone or in fruit tea formulas, which are recommended for drinking during pregnancy instead of tea. Its petals can contain similar and even higher amounts of Al as tea, which is a known Al accumulator. Our research investigated whether the regular intake of H. sabdariffa infusion leads to increased burden of Al. Sixteen days of ingestion of H. sabdariffa infusion (c _Al = 0.5 mg.L^-1) led to increased but unbalanced levels (15-86 μg L^-1) of Al in urine compared to a period when the infusion was not ingested. The highest amounts of Al excreted were observed every third day during the ingestion. Mild health problems, such as nausea and dizziness (which could be related to plant properties) were reported by more sensitive volunteers.Our results suggest that the tea infusion from H. sabdariffa petals increases body burden of Al and, therefore, sensitive individuals as pregnant women and people with kidney problems should be cautious with excessive consumption of hibiscus infusion or fruit teas containing this plant. However, further study including more individuals is needed to fully confirm our preliminary results.

Multivariate data reduction and discrimination of black and green teas due to the physical fractionation pattern of selected metals determined in their infusions

An analytical scheme for the physical fractionation of Al, Ba, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Sr and Zn in black and green teas infusions was proposed. It was based on the ultrafiltration/centrifugation through five membranes having molecular weight cut-offs of 100, 50, 30, 10 and 5kDa. The concentrations of the studied metals in the highest and the lowest molecular weight fractions were found to classify and discriminate the analyzed teas infusions much better than the total metals concentrations. The differences in the physical fractionation patterns of these metals assessed for both tea varieties was profound and let to simply classify the infusions of different black and green teas by principal component analysis and linear discriminant analysis.

Content of Selected Minerals and Active Ingredients in Teas Containing Yerba Mate and Rooibos

The study aimed to determine the content of selected elements: sodium, potassium, copper, zinc, iron, manganese and active ingredients such as phenolic acids and tannins in teas containing Yerba Mate and Rooibos cultivated in various areas. The study material comprised six samples of Yerba Mate teas and of Rooibos teas, both tea bags and leaves, purchased in Puławy and online via Allegro. In total, 24 samples were tested. Yerba Mate was particularly abundant in Mn and Fe. The richest source of these elements was Yerba Mate Yer-Vita (2261.3 mg · kg(-1) d.m.) and (691.6 mg · kg(-1) d.m.). The highest content of zinc was determined in Yerba Mate Amanda with lime (106.0 mg · kg(-1) d.m.), while copper was most abundant in Yerba Mate Big-Active cocoa and vanilla (14.05 mg · kg(-1) d.m.). In Rooibos, the content of sodium was several times higher than in Yerba Mate. A clear difference was observed in the content of minerals in dry weight of the examined products, which could be a result of both the taxonomic distinctness and the origin of the raw material. Leaf teas turned out to be a better source of tannins; on the other hand, tea bags contained substantially more phenolic acids. The richest source of phenolic acids was Yer-Vita in bags (1.8 %), and the highest amount of tannins was recorded in the leaf tea Green Goucho caramel and dark chocolate (9.04 g · 100 g(-1) d.m.). In Rooibos products, the highest content of phenolic acids was recorded in tea bags (Savannah with honey and vanilla 0.96 %), and tannins in (Lord Nelson with strawberry and cream 7.99 g · 100 g (-1) d.m.).

The effects of aluminium on plant growth in a temperate and deciduous aluminium accumulating species

Aluminium (Al) is a phytotoxic element affecting the growth and yield of many crop plants, especially in the tropics. Yet, some plants are able to accumulate high levels of Al. The monogeneric family Symplocaceae represents an Al accumulating family including many tropical and evergreen species with high Al levels in their above ground plant tissues. It is unclear, however, whether Al accumulation also characterises temperate species of Symplocos, and whether or not the uptake has a beneficial growth effect. Here, we investigate if the temperate, deciduous species Symplocos paniculata is able to accumulate Al by growing seedlings and saplings in a hydroponic setup at pH 4 with and without Al. Pyrocatechol-violet (PCV) and aluminon staining was performed to visualize Al accumulation in various plant tissues. Both seedlings and saplings accumulate Al in their tissues if available. Mean Al levels in leaves were 4107 (±1474 mg kg^-1) and 4290 (±4025 mg kg^-1) for the seedlings and saplings, respectively. The saplings treated without Al showed a high mortality rate unlike the Al accumulating ones. The seedlings, however, showed no difference in growth and vitality between the two treatments. The saplings treated with Al showed new twig, leaf and root development, resulting in a considerable biomass increase. PCV and aluminon staining indicated the presence of Al in leaf, wood and bark tissue of the plants. S. paniculata shares the capacity to accumulate Al with its tropical sister species and is suggested to be a facultative accumulator. Whether or not Al has a beneficial effect remains unclear, due to developmental differences between seedlings and saplings. Al is suggested to be transported via the xylem transport system into the leaves, which show the highest Al levels. Radial transport via ray parenchyma to bark tissue is also likely given the high Al concentrations in the bark tissue.

Aluminum uptake and migration from the soil compartment into Betula pendula for two different environments: a polluted and environmentally protected area of Poland

This paper presents the impact of soil contamination on aluminum (Al) concentrations in plant parts of Betula pendula and a possible way of migration and transformation of Al in the soil-root-stem-twig-leaf system. A new procedure of Al fractionation based on extraction in water phase was applied to obtain and measure the most available forms of Al in soils and B. pendula samples. In addition, total Al content was determined in biological samples and pseudo total Al content in soil samples collected under plant saplings, using atomic absorption spectrometry with flame atomization. A number of relations concerning the occurrence of Al and Ca in soils and plant parts of B. pendula (tap roots, lateral roots, stem, twigs, and leaves) were observed. Based on the research findings, the mechanism of Al migration from soil to the leaves of B. pendula can be presented. It was found that aluminum uptake may be limited in roots by high calcium concentration. The application of a new procedure based on the simple sequential extraction of water-soluble fractions (the most available and exchangeable fractions of Al) can be used as an effective tool for the estimation of aluminum toxicity in soils and plants.

Evaluation of trace metal and polychlorinated biphenyl levels in tea brands of different origin commercialized in Italy

The objectives of this study were to investigate the trace element (Hg, Cd, Pb, Cu, Zn, Ni, Fe, Cr and Se) and polychlorinated biphenyl (PCBs) content of several commercially available brands of green and black tea marketed in Italy. The concentrations these chemicals were found to be variable and largely dependent upon the type and brand of analysed tea. The most abundant element among the essential elements was Fe, followed by Zn, Cu, Se, Ni and Cr, whereas Pb was the predominant among the tested nonessential elements followed by Hg and Cd. Assessment based on several available guidelines showed that element content were low, except for Hg and Ni. The PCBs concentrations were generally low, with a homologue profile dominated by low-chlorinated congeners, namely three- and tetra-PCBs accounting for more than 60% of the total residue. Apart from trace elements, this is the first study documenting in detail the concentrations and congener distribution of PCBs in tea samples of different origin.

Aluminium (Al) fractionation and speciation; getting closer to describing the factors influencing Al(3+) in water impacted by acid mine drainage

Acid mine drainage (AMD) severely impacts the water chemistry of a receiving resource, changing the occurrence, speciation and toxicity of metals such as Aluminium (Al). The toxicity of Al is determined by its speciation represented by the labile monomer Al fraction or Al(3+). The purpose of the study was to combine fractionation and Visual MINTEQ speciation to calculate the effect of AMD altered water chemistry on Al speciation and Al(3+) concentration. Water in rivers impacted by AMD presented with monomeric Al (Almon) concentrations between 0.35 and 15.37mgL(-)(1) which existed almost exclusively in the toxic labile form (98%). For the reference site, Almon was less than 2% (10μgL(-1)), suggesting significantly lower Al toxicity. Principal component analysis plots illustrated that labile Al was directly related to the total Al and iron concentrations and strongly influenced by parameters such as pH, electrical conductivity, sulphate and dissolved organic carbon. Visual MINTEQ modelling was used to determine the primary Al species distribution. The dominant form of Al in AMD impacted water was AlSO4(+), which increased proportionally with the sulphate and Al(3+) concentration. Heavily impacted areas, presented with an average of 1mgmL(-)(1) Al(3+), which poses a potential human health risk. A novel centrifugal ultrafiltration method was investigated as an alternative to determining Almon to simplify the speciation of Al. Monomeric and centrifugal ultrafiltrated (<10kD) Al fractions were significantly similar (p=0.74), suggesting that ultrafiltration may present a time, energy and cost saving alternative to organic extraction of Almon.

Aluminium dynamics from soil to tea plant (Camellia sinensis L.): is it enhanced by municipal solid waste compost application?

Application of municipal solid waste compost (MSWC) in tea (Camellia sinensis L.) cultivation can increase the fertility status of soils and thus enhance the plant growth. The present study attempts at application of MSWC in tea (TV1 and TV23 clones) cultivation to assess the effect of different doses of MSWC on growth and translocation potential of Al on this plant as well as fate of Al in soil, through the calculation of a risk assessment code (RAC). The sequential extraction of Al in MSWC amended soils showed that the fractionation of Al in soil changed after compost application, with an overall increase of the fractions associated to with Fe-Mn oxides, organic and of the residual fraction. The accumulation of Al in different parts ofC. sinensisL., grown on MSWC amended soil effected an overall increased growth of the plant with increasing doses of MSWC. According to RAC, Al falls in medium to high risk, though no adverse effect on plant health was observed. Tea plants were found to adapt well to MSWC amended soils. However, long term field trials are necessary to completely assess the risk of Al accumulation in soils upon MSWC application. Hierarchical cluster analysis was applied aiming to check for the presence of homogenous groups among different treatments. It was found that in both TV1 and TV23, treatments formed two different groups.

Systematic review of potential health risks posed by pharmaceutical, occupational and consumer exposures to metallic and nanoscale aluminum, aluminum oxides, aluminum hydroxide and its soluble salts

Abstract Aluminum (Al) is a ubiquitous substance encountered both naturally (as the third most abundant element) and intentionally (used in water, foods, pharmaceuticals, and vaccines); it is also present in ambient and occupational airborne particulates. Existing data underscore the importance of Al physical and chemical forms in relation to its uptake, accumulation, and systemic bioavailability. The present review represents a systematic examination of the peer-reviewed literature on the adverse health effects of Al materials published since a previous critical evaluation compiled by Krewski et al. (2007) . Challenges encountered in carrying out the present review reflected the experimental use of different physical and chemical Al forms, different routes of administration, and different target organs in relation to the magnitude, frequency, and duration of exposure. Wide variations in diet can result in Al intakes that are often higher than the World Health Organization provisional tolerable weekly intake (PTWI), which is based on studies with Al citrate. Comparing daily dietary Al exposures on the basis of "total Al"assumes that gastrointestinal bioavailability for all dietary Al forms is equivalent to that for Al citrate, an approach that requires validation. Current occupational exposure limits (OELs) for identical Al substances vary as much as 15-fold. The toxicity of different Al forms depends in large measure on their physical behavior and relative solubility in water. The toxicity of soluble Al forms depends upon the delivered dose of Al(+3) to target tissues. Trivalent Al reacts with water to produce bidentate superoxide coordination spheres [Al(O2)(H2O4)(+2) and Al(H2O)6 (+3)] that after complexation with O2(•-), generate Al superoxides [Al(O2(•))](H2O5)](+2). Semireduced AlO2(•) radicals deplete mitochondrial Fe and promote generation of H2O2, O2 (•-) and OH(•). Thus, it is the Al(+3)-induced formation of oxygen radicals that accounts for the oxidative damage that leads to intrinsic apoptosis. In contrast, the toxicity of the insoluble Al oxides depends primarily on their behavior as particulates. Aluminum has been held responsible for human morbidity and mortality, but there is no consistent and convincing evidence to associate the Al found in food and drinking water at the doses and chemical forms presently consumed by people living in North America and Western Europe with increased risk for Alzheimer's disease (AD). Neither is there clear evidence to show use of Al-containing underarm antiperspirants or cosmetics increases the risk of AD or breast cancer. Metallic Al, its oxides, and common Al salts have not been shown to be either genotoxic or carcinogenic. Aluminum exposures during neonatal and pediatric parenteral nutrition (PN) can impair bone mineralization and delay neurological development. Adverse effects to vaccines with Al adjuvants have occurred; however, recent controlled trials found that the immunologic response to certain vaccines with Al adjuvants was no greater, and in some cases less than, that after identical vaccination without Al adjuvants. The scientific literature on the adverse health effects of Al is extensive. Health risk assessments for Al must take into account individual co-factors (e.g., age, renal function, diet, gastric pH). Conclusions from the current review point to the need for refinement of the PTWI, reduction of Al contamination in PN solutions, justification for routine addition of Al to vaccines, and harmonization of OELs for Al substances.

Aluminium and other elements in selected herbal tea plant species and their infusions

The determination of Al, B, Cu, Fe, Mn, Ni, P, Zn and Ca, K, Mg by inductively coupled plasma optical emission spectrometry (ICP-OES) and flame atomic absorption spectroscopy (FAAS), respectively, in digests and infusions of Hibiscus sabdariffa (petals), Rosa canina (receptacles), Ginkgo biloba (leaves), Cymbopogon citratus (leaves), Aloe vera (leaves) and Panax ginseng (roots) was carried out in this study. Particular attention has been given to Al and heavy metals for the identification of possible raw material contaminants, their transformation into the infusion and for predicting their eventual role in the human diet during daily consumption. Additionally, Ion Chromatography (IC) speciation of Al in the leachates was carried out. In dry herbs, hibiscus and ginkgo appeared to contain the greatest contents of Al, Fe, K, Mn, Ni, Zn and B, Mg, P, respectively. A. vera contained the highest amount of Ca and highest values of Cu and P were observed in ginseng. In infusions, the topmost concentrations of Al, B, Cu, Fe, P, K, Mn, Ni, Zn were detected in those prepared from hibiscus petals, Ca from aloe leaves and Mg from leaves of ginkgo. According to a possible daily consumption exceeding 1 L, hibiscus decoction was identified as potentially dietetically significant in the content of certain elements. It seems to be possibly one of the top contributors of B from food (up to 5.5±0.2 mg/L). The Mg contained in the infusion (up to 106±5 mg/L) may be a contributor in the attenuation of blood pressure. A high amount of accessible Mn (up to 17.4±1.1 mg/L) can probably have an adverse effect in humans. The total Al allowance (up to 1.2±0.1 mg/L) suggests that no more than 1 L of the hibiscus infusion should be consumed per day by sensitive individuals including pregnant women and should be completely excluded from the diet of children under 6 months of age and children with chronic renal failure.

Fractionation of residual Al in natural water treatment from reservoir with poly-aluminum-silicate-chloride (PASiC): effect of OH/Al, Si/Al molar ratios and initial pH

An aluminum fractionation study was conducted for a surface reservoir water treatment to understand the performance of poly-aluminum-silicate-chloride (PASiC) in terms of the residual Al fractions as a function of initial pH. The coagulation performance expressed as turbidity and organic matter removal was established as supporting data. Some extra data were evaluated in terms of the residual Al ratio of the composite PASiC coagulant. The main residual Al sources were the Al fractions derived from the use of PASiC. The turbidity and organic matter removal ability was optimal at initial pH 6.00-7.00, while the concentrations of various residual Al species and the residual Al ratio of PASiC were minimal at an initial pH range of 7.00-8.00. Under the conditions of OH/Al molar ratio = 2.00 and Si/Al molar ratio = 0.05, PASiC had superior coagulation performance and comparatively low residual Al concentrations. The Al fraction in the composite PASiC coagulant seldom remained under such conditions. Experimental data also indicated that the suspended (filterable) Al fraction was the dominant species, and organic-bound or organo-Al complex Al was considered to be the major species of dissolved Al in water treated by PASiC coagulation. Additionally, the dissolved inorganic monomeric Al species dominated the dissolved monomeric Al fraction.

Trace elements in different brands of yerba mate tea

Yerba mate (Ilex paraguariensis), a widely consumed beverage in South America, contains various biochemically active substances, among them are several minerals. This paper reports on the results of a survey of trace elements in the yerba mate infusions. Three different commercially available trademarks of I. paraguariensis were evaluated, simulating the popular mode of preparation. Atomic absorption analyses for cadmium, lead, copper, zinc, aluminum, iron, chromium, manganese, molybdenum, and silver were performed using a graphite furnace. The levels ranged from 0.03 to 0.06 mg/L for copper, from 0.41 to 1.0 mg/L for zinc, from 0.32 to 1.7 mg/L for aluminum, from 0.12 to 0.23 mg/L for iron, from 2.3 to 7.0 mg/L for manganese, and from 0.01 to 0.03 mg/L for silver. The levels of chromium did not exceed 0.005 mg/L, while molybdenum, cadmium, and lead were lower than <0.01 mg/L. Metal content in mate tea infusions depends on a number of factors, some of which are controllable and others not, but the differences among various sources are admissible. Trace elements in mate plants seem to be weakly bounded to the substrate. The concentration of biometals does not exceed the limits accepted by Brazilian and international legislation when available.

Macro- and micro- elements in some herbal drug raw materials and their water extracts consumed in Poland

The concentrations of seven macro- and microelements (K, Mg, Ca, Na, Fe, Zn, Mn) in 59 herbs (herbs, leaves, flowers, fruits, roots), which are commercially available and frequently used in Poland for medical purposes as well as in their water extracts (infusions and decoctions), were determined after microwave mineralization. The data obtained show that all herbal raw materials analysed contain macroelements in the range of mg g−1 on d.w. whereas microelements in the range of mg kg−1 on d.w. and that elemental concentrations varied widely. On the basis of a comparison of concentrations of elements in herbal raw materials examined and water extracts prepared from them, the extraction efficiency was expressed as a percent of the total content of each element present in the infusion or decoction. The percentages of macro- and micro- elements leaching from different morphological parts of plants into water extracts varied across a wide range of values, from 1% in the case of Na to 56% in the case of K. Real daily intake of the macro- and microelements elements through one cup of infusions or decoctions were shown that water extracts from herbal raw materials are not an important source of bioelements in human diet.