Chromium in soil and tea ( Camellia sinensis L.) infusion: Does soil amendment with municipal solid waste compost make sense?

Influence of Industrial Wastewater Irrigation on Heavy Metal Content in Coriander (Coriandrum sativum L.): Ecological and Health Risk Assessment

The primary objective of this study was to determine the heavy metal contents in the water-soil-coriander samples in an industrial wastewater irrigated area and to assess the health risks of these metals to consumers. Sampling was done from areas adjoining the Chistian sugar mill district Sargodha and two separate sites irrigated with groundwater (Site 1), and sugar mill effluents (Site 2) were checked for possible metal contamination. The water-soil-coriander continuum was tested for the presence of cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Ni), lead (Pb), and zinc (Zn). The mean concentrations of all metals were higher than the permissible limits for all studied metals except for Mn in the sugar mill wastewater, with Fe (8.861 mg/L) and Zn (9.761 mg/L) exhibiting the highest values. The mean levels of Fe (4.023 mg/kg), Cd (2.101 mg/kg), Cr (2.135 mg/kg), Cu (2.180 mg/kg), and Ni (1.523 mg/kg) were high in the soil at Site 2 in comparison to the groundwater irrigated site where Fe (3.232 mg/kg) and Cd (1.845 mg/kg) manifested high elemental levels. For coriander specimens, only Cd had a higher mean level in both the groundwater (1.245 mg/kg) and the sugar mill wastewater (1.245 mg/kg) irrigated sites. An estimation of the pollution indices yielded a high risk from Cd (health risk index (HRI): 173.2), Zn (HRI: 7.012), Mn (HRI: 6.276), Fe (HRI: 1.709), Cu (HRI: 1.282), and Ni (HRI: 1.009), as all values are above 1.0 indicating a hazard to human health from consuming coriander irrigated with wastewater. Regular monitoring of vegetables irrigated with wastewater is strongly advised to reduce health hazards to people.

Monitoring and evaluating the dietary risk of trace elements content in bottled and hand-shaken tea in Taiwan

Tea is the most frequently consumed beverage worldwide and is obtained from the leaves Camellia sinensis. The traditional way of tea consumption through brewing is gradually being replaced by the consumption of bottled and hand-shaken tea. Despite the different ways of tea consumption, trace elements accumulation and contamination of tea leaves have caused concerns. However, limited studies have reported trace element concentrations in different types of tea in bottled or hand-shaken tea and their health risks. This study aimed to determine the level of trace elements (V, Cr, Co, As, Cd, Pb, Mn, and Zn) in green tea, black tea, and Oolong tea in two varieties of products (bottled and hand-shaken tea). The health risks associated with tea consumption in various age subgroups among Taiwan's general population were also estimated. A Monte Carlo simulation was applied to estimate the distribution of daily trace elements intake through bottled and hand-shaken tea consumption. As to the non-carcinogenic risks, the Monte Carlo simulation showed that hand-shaken green tea had a higher percentage of hazard index (HI) >1 (1.08%~6.05%) among all age groups. As to carcinogenic risks, the Monte Carlo simulation showed that the risks of As exposure from bottled Oolong tea and hand-shaken black, green, and Oolong teas in the 90th percentile in >18 to ≤65 and >65-year-old groups were higher than 10^-6. The current study findings provided some information about trace elements of both bottled and hand-shaken tea and human health risks in the general population of Taiwan.

Insights into the effects of tea pruning litter biochar on major micronutrients (Cu, Mn, and Zn) pathway from soil to tea plant: An environmental armour

A field study was conducted from 0 to 360 days to investigate the effect of tea pruning litter biochar (TPLBC) on the accumulation of major micronutrients (copper: Cu, manganese: Mn, and zinc: Zn) in soil, their uptake by tea plant (clone: S.3 A/3) and level of contamination in soil due to TPLBC. To evaluate the level of contamination due to TPLBC, a soil pollution assessment was carried out using the geo-accumulation index (I_geo), enrichment factor (EF), contamination factor (CF), potential ecological risk factor (PERF), individual contamination factor (ICF), and risk assessment code (RAC). The total content of Cu, Mn, and Zn gradually increased with increasing doses of TPLBC at 0D, and then decreased with time. The fractionation of the three micronutrients in soil changed after the application of TPLBC. The contamination risk assessment of soil for Cu, Mn, and Zn based on the I_geo, EF, CF, PERF,ICF, and RAC suggested that the application of TPLBC does not have any adverse effect on soil. Except for Mn, the bioconcentration and translocation factors were less than one for Cu and Zn. Results from this study revealed that the application of 400 kg TPLBC ha^-1 is significantly better than the other treatments for Cu, Mn, and Zn at a 5% level of significance.

Characterization of vermicompost of coconut husk mixed with cattle dung: physicochemical properties, SEM, and FT-IR analysis

The present work evaluated the potential of vermicomposting in management of different ratios of coconut husk waste (CH) and cattle dung (CD) viz (waste: CD) 0:100 (CH₀), 25:75 (CH₂₅), 50:50 (CH₅₀), 75:25 (CH₇₅), and 100:0 (CH₁₀₀) using Eisenia fetida for 120 days. The physicochemical properties were analyzed in vermicompost samples taken on the 0 and 120th day. Co-composting with cattle manure improved their acceptability for E. fetida as well as their physicochemical properties. In a 50:50 (CH₅₀) ratio, the lowest mortality and maximum growth in terms of number and biomass of earthworms were observed. The results revealed that during pre-vermicompost to post-vermicompost, nutrients such as nitrogen, phosphorus, and sodium increased, whereas in all vermicomposting end products organic carbon and the C:N ratio decreased significantly. Except zinc, all heavy metals decreased significantly (p < 0.05) over initial in all the feed mixtures. Seed germination tests indicated that the mature and non-phytotoxic vermicompost has been formed at the end of the experiment. The Fourier transmission infrared spectroscopy (FT-IR) and scanning electron microscopic (SEM) images of vermicompost demonstrated the excellent maturity of the compost.

Potentially Toxic Metal Accumulation in Spinach (Spinacia oleracea L.) Irrigated with Industrial Wastewater and Health Risk Assessment from Consumption

This study aimed to determine the potentially toxic metal contents in soil and spinach samples in areas irrigated with industrial wastewater and to evaluate the potentially toxic metal accumulation in spinach samples according to pollution indices. Water, soil and spinach samples were analysed using atomic absorption spectrophotometer (Perkin-Elmer AAS-300). In this study, it was determined that the potentially toxic metal values ​​in the spinach samples irrigated with groundwater and sugar industry wastewater varied between 1.59 and 1.84, 0.22-0.68, 0.56-1.14, 1.41-1.56, 1.62-3.23, 0.57-1.02, 0.86-1.33, 0.20-0.32 and 0.35-2.10 mg/kg for Cd, Co, Cr, Cu, Fe, Ni, Pb, Zn and Mn, respectively. It was concluded that the difference between the metal values ​​in the spinach samples according to the irrigation sources was statistically significant, except for Cu and Pb (p > 0.05). According to the results of this study, there is no health risk for Pb, Co and Cr with HRI values ​​below 1.0, while there is a risk for Cd, Cu, Fe, Ni, Mn and Zn. The much higher HRI values ​​of Cd than 1 (196.8 and 169.6) suggested that this metal is likely to cause significant health problems in the region.

Comparison between a Traditional (Horse Manure) and a Non-Conventional (Cork Powder) Organic Residue in the Uptake of Potentially Toxic Elements by Lettuce in Contaminated Soils

The use of natural organic correctives is a current agricultural practice that may have advantages for the production of plants in contaminated soils. Cork powder is a natural sub-product of the cork industry that has several potential benefits compared to more commonly used soil amendments. In this work, an evaluation was performed of the use of cork powder (a non-conventional organic residue) and horse manure (traditionally used in agriculture) to control the availability of potentially toxic elements in artificially contaminated soils. Four concentrations were used for each element: Cr (100 to 800 mg kg−1), Ni (37.5 to 300 mg kg−1), Zn (150 to 1200 mg kg−1), Cd (1.5 to 12 mg kg−1) and Pb (150 to 1200 mg kg−1). The accumulation of these elements in lettuce plants grown in pots under controlled conditions was evaluated. With the exception of Cd, no significant differences were detected in the absorption of the different elements by lettuce plants at the studied amounts of correctives applied (1% for cork powder and 0.5% for horse manure). Cadmium was the element that accumulated most in lettuce. Cork powder was shown to be less effective than horse manure in controlling the bioavailability of these elements in the soil. Further tests with chemically modified cork products could improve its efficiency.

Trace metal accumulation in pepper (Capsicum annuum L.) grown using organic fertilizers and health risk assessment from consumption

Organic farming and healthy nutrition are among the most popular topics of recent times. However, organic fertilizers, which are one of the important elements of organic agriculture, have the potential to threaten human health with the toxic substances they may contain. The present study aimed to observe the effect of farmyard manure, poultry waste and press mud on metal accumulation in pepper (Capsicum annuum L.) to determine the pollution severity of soil and to examine the health risk due to the consumption of organic fertilizer applied pepper. The multipurpose pot experiment was conducted to study the agronomical growth performance and accretion of metals in C. annuum grown with different organic fertilizers in the soil at the area of the Department of Botany, University of Sargodha, Pakistan. The trace metal contents in soil and C. annuum samples were analysed by atomic absorption spectrophotometer (AA-6300 Shimadzu Japan). Trace metal concentrations in soil samples ranged from 0.152 to 0.850, 2.167 to 5.812, 0.345 to 1.235, 2.682 to 5.875, 0.095 to 0.558, 6.132 to 17.062, 0.172 to 2.235 and 6.670 to 22.585 mg/kg for Cd, Co, Cr, Cu, Pb, Fe, Mn and Zn, respectively. In pepper samples, trace metal concentrations ranged from 0.364 to 2.206, 0.305 to 4.042, 0.272 to 1.160, 1.132 to 1.305, 0.164 to 0.204, 4.736 to 17.000, 0.844 to 1.150 and 14.751 to 18.385 mg/kg for Cd, Co, Cr, Cu, Pb, Fe, Mn and Zn, respectively. The accumulation of Cd and Pb had higher values of HRI than 1 and these values suggested that these metals had probability to cause health problems.

Contents of Chromium and Arsenic in Tea (Camellia sinensis L.): Extent of Transfer into Tea Infusion and Health Consequence

Tea (Camellia sinensis L.) is the most popular beverage in the world after water. Due to acidophilic nature of tea plant, it has inherent tendency to uptake metals/metalloids including the toxic ones from the soil which is of great concern worldwide. In this study, level of chromium (Cr) and arsenic (As) were assessed in four hundred ninety-seven (497) black tea samples collected from six tea growing regions of Assam and North Bengal, India. The average concentration of Cr and As in the tested black tea samples was 10.33 and 0.11 μg g^-1, respectively. Since tea is consumed as a beverage, transfer of Cr and As from black tea to its hot water extract (also known as tea infusion) was also accessed. The amount of Cr and As determined in the tea infusion was much less (< 0.20 to 1.38 μg g^-1 for Cr and < 3.60 to 34.79 μg kg^-1 for As) than those in the black teas with the transfer rate up to 5.96% and 8.53%, respectively. The present study showed that values of hazard quotient were well below one suggesting that intake of Cr and As from consumption of five cups of tea equivalent to 10 g black tea would not impose any health hazard.

Treated Wastewater and Fertigation Applied for Greenhouse Tomato Cultivation Grown in Municipal Solid Waste Compost and Soil Mixtures

Low-fertility soil and the use of brackish water for irrigation act as obstacles and limit crop production. The utilization of municipal solid waste (MSW), compost (C), and treated wastewater (TWW) is receiving attention nowadays not only to overcome the above limitations but also as an efficient way for waste management and reuse of raw materials. In the present study, MSW compost in different ratios (5%, 10%, 20%, and 40%), fertigation and/or irrigation with TWW were studied in tomato plants (Solanum lycopersicum L.). The addition of compost increased organic content, pH, electrical conductivity (EC), and mineral content of the growing media, while fertigation and TWW supported the mineral status of the growing media, and this was reflected in the increase of N, K, and Na in tomato leaves. Plants grown in compost-based media with fertigation produced more leaves, compared to the control, while irrigation with TWW did not increase the number of leaves. Plant biomass increased with the application of ≥20% C, fertigation, and/or TWW applications. Plant yield increased in 40% C, while fertigation increased yield in case of lower (5%-10% C) compost ratios, but TWW application did not change the yield. The combination of high C ratios and fertigation and/or TWW decreased tomato fresh weight. Different levels of C did not affect leaf photosynthesis, stomatal conductance, internal CO2 concentration, and chlorophyll fluorescence, but, in general, the combination of compost with fertigation and/or TWW affected them negatively. Fruit total soluble solids, acidity, ascorbic acid, firmness, and total phenolics were increased with the high ratios of compost and/or fertigation and TWW applications, but marketability did not. Bacteria (total coliform and Escherichia coli) units increased in growing media subjected to TWW, but lower levels were counted on the fruit, mainly due to splashing or fruit contact with the soil. The results indicate that up to 40% C can be added into the substrate, as increased plant growth and maintained plant yield for greenhouse tomato cultivation is observed, while fertigation and TWW could be used in a controlled manner as alternative means for nutrient and irrigation in vegetables following safety aspects.

Zn, Ni, Mn, Cr, Pb and Cu in soil-tea ecosystem: The concentrations, spatial relationship and potential control

Excessive accumulation of heavy metals in tea has certain health risk to the consumers. To discuss the spatial relationship between heavy metals in tea leaves and soil in a county scale, 74 samples of tea leaves and corresponding subsoil (15-30 cm) were collected in the tea plantations of Lishui, Nanjing, China. The total Zn, Ni, Mn, Cr, Pb and Cu in both tea leaves and soil samples, as well as pH value in soil were analyzed. The results of regression showed that the Mn and Cr in tea leaves were increased when the Mn and Cr in soil were at high levels, and higher pH decreased Zn, Ni, Mn and Cu contents in tea leaves. Moreover, distance to village and metal industry had negative impacts on the Mn level in soil. It is necessary to control the pH of soil in tea plantations which are close to villages or metal industries, as well as, to search more appropriate areas, where are far away from villages or metal industries, to plant tea should be taken into consideration. In addition, 17.57% of the samples have higher concentration of Pb than the maximum limits was found in tea plantation of Lishui. Heavy metals (Cr) standards regarding leafy vegetables is used for reference in this study, as there are no maximum levels of contaminants (MLC) in tea. It is significant to construct a targeted standard of heavy metals contents that could applicable throughout the world for reduce the health risks to the consumers.

Micronutrients (B, Co, Cu, Fe, Mn, Mo, and Zn) content in made tea (Camellia sinensis L.) and tea infusion with health prospect: A critical review

Tea (Camellia sinensis L.) is a perennial acidophilic crop, and known to be a nonalcoholic stimulating beverage that is most widely consumed after water. The aim of this review paper is to provide a detailed documentation of selected micronutrient contents, viz. boron (B), cobalt (Co), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), and zinc (Zn) in made tea and tea infusion. Available data from the literature were used to calculate human health aspect associated with the consumption of tea infusion. A wide range of micronutrients reported in both made tea and tea infusion could be the major sources of micronutrients for human. The content of B, Co, Cu, Fe, Mn, Mo, and Zn in made tea are ranged from 3.04 to 58.44 μg g^-1, below detectable limit (BDL) to 122.4 μg g^-1, BDL to 602 μg g^-1, 0.275 to 13,040 μg g^-1, 0.004 to 15,866 μg g^-1, 0.04 to 570.80 μg g^-1 and 0.01 to 1120 μg g^-1, respectively. Only 3.2 μg L^-1 to 7.25 mg L^-1, 0.01 μg L^-1 to 7 mg L^-1, 3.80 μg L^-1 to 6.13 mg L^-1, 135.59 μg L^-1 -11.05 mg L^-1, 0.05 μg L^-1 to 1980.34 mg L^-1, 0.012 to 3.78 μg L^-1, and 1.12 μg L^-1 to 2.32 μg L^-1 of B, Co, Cu, Fe, Mn, Mo, and Zn, respectively, are found in tea infusion which are lower than the prescribed limit of micronutrients in drinking water by World Health Organization. Furthermore, micronutrient contents in tea infusion depend on infusion procedure as well as on the instrument used for analysis. The proportion of micronutrients found in different tea types are 1.0-88.9% for B, 10-60% for Co, 2.0-97.8% for Cu, 67.8-89.9% for Fe, 71.0-87.4% for Mn, 13.3-34% for Mo, and 34.9-83% for Zn. From the results, it can also be concluded that consumption of three cups of tea infusion per day does not have any adverse effect on human health with respect to the referred micronutrients rather got beneficial effects to human.

Paradigm shift of contamination risk of six heavy metals in tea (Camellia sinensis L.) growing soil: A new approach influenced by inorganic and organic amendments

The present study provides several contamination and ecological risk indices for selected metals (Cd, Cr, Cu, Mn, Ni and Zn) in tea (Camellia sinensis L.; cv. S.3A/3) growing soil influenced by lower to higher doses of inorganic and organic amendments. While ecological risk indices were applied, it was observed that same treatment showed different risk levels but contamination risk status did not vary significantly. All the indices showed significant correlation with heavy metals' concentration in young shoots of tea plants. As the indices characterized experimental soils with different extents of contamination, it would be important to standardize the indices with long term experiments followed by generation of new index. Therefore, we formulated a new contamination index named as Tea Research Association Heavy Metal Contamination Index (TRAHMCI) for tea growing soils. TRAHMCI is based on the probable change of metal status in soil with progress of growth of tea plant. This could be useful to negate discrepancies arised from use of various existing metal contamination indices in tea growing soils amended with different doses of fertilizers. TRAHMCI was formulated based on individual contamination factor using statistical technique and applied to the present dataset which provided a more holistic understanding of overall tea growing soil behavior. The limitation of the developed TRAHMCI index is that, the index had not been validated for other crops in our study not to claim its effective use for crops other than tea. As already mentioned, this new index had been formulated by taking tea as the test crop with above mentioned six heavy metal contents in young shoot and made tea.

Vermiremediation of toxic jute mill waste employing Metaphire posthuma

India has a giant jute-producing basket which produces considerable quantity of toxic jute mill waste (JMW). Conversely, report on usability potential of JMW is rather scanty. The present study illustrates the efficiency of vermicomposting in bioconversion of JMW for agricultural use. Various combinations of JMW, cow dung, and vegetable waste were fed to Metaphire posthuma in vermireactors. Rapid increment of earthworm count, body weight, and cocoon production was evidenced. Total organic carbon and pH reduction was noteworthy, but N, P, and K availability, formation of stable humic acid C, fulvic acid C, and microbial biomass C substantially increased due to vermicomposting. FTIR spectroscopy confirmed a higher stability of vermicomposted JMW over the composted product. A significant decline in heavy metal concentration (Cr, Pb, Fe, and Zn) in the vermicomposted JMW further establishes the potential of vermicomposting with M. posthuma in successful conversion of the toxic JMW into valuable product.

Determination of heavy metals in the soils of tea plantations and in fresh and processed tea leaves: an evaluation of six digestion methods

Background

The aim of this study was to determine the levels of cadmium (Cd), chromium (Cr), lead (Pb), arsenic (As) and selenium (Se) in (1) fresh tea leaves, (2) processed (black) tea leaves and (3) soils from tea plantations originating from Bangladesh.

Methods

Graphite furnace atomic absorption spectrometry (GF-AAS) was used to evaluate six digestion methods, (1) nitric acid, (2) nitric acid overnight, (3) nitric acid–hydrogen peroxide, (4) nitric–perchloric acid, (5) sulfuric acid, and (6) dry ashing, to determine the most suitable digestion method for the determination of heavy metals in the samples.

Results

The concentration ranges of Cd, Pb, As and Se in fresh tea leaves were from 0.03–0.13, 0.19–2.06 and 0.47–1.31 µg/g, respectively while processed tea contained heavy metals at different concentrations: Cd (0.04–0.16 µg/g), Cr (0.45–10.73 µg/g), Pb (0.07–1.03 µg/g), As (0.89–1.90 µg/g) and Se (0.21–10.79 µg/g). Moreover, the soil samples of tea plantations also showed a wide range of concentrations: Cd (0.11–0.45 µg/g), Pb (2.80–66.54 µg/g), As (0.78–4.49 µg/g), and Se content (0.03–0.99 µg/g). Method no. 2 provided sufficient time to digest the tea matrix and was the most efficient method for recovering Cd, Cr, Pb, As and Se. Methods 1 and 3 were also acceptable and can be relatively inexpensive, easy and fast. The heavy metal transfer factors in the investigated soil/tea samples decreased as follows: Cd > As > Se > Pb.

Conclusion

Overall, the present study gives current insights into the heavy metal levels both in soils and teas commonly consumed in Bangladesh.

Novel synthesis of an iron oxalate capped iron oxide nanomaterial: a unique soil conditioner and slow release eco-friendly source of iron sustenance in plants

Iron (Fe) is a vital plant-derived micronutrient in the human diet.

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.