Metal Concentrations In Tissues Research Articles

Sex and sex-related differences in gamete development progression impinge on biomarker responsiveness in sentinel mussels

In marine pollution monitoring, the biomarkers recorded in sentinel organisms are influenced by natural confounding factors that may jeopardise their interpretation. Among these confounding factors, little is known about the influence of sex along the annual reproductive cycle. The present investigation aims at contributing to understand how sex and sex-related differences in gamete development progression impinge on biomarker baseline values and on biomarker responsiveness to pollution in sentinel mussels. Mussels (Mytilus galloprovincialis) were collected from a relatively clean locality and from a chronically polluted site in the Basque Coast (Bay of Biscay) in January, April, August and November. Sex and gametogenesis stages were determined for each mussel. Tissue concentration of metals and PAHs was analysed. A battery of biomarkers was investigated: cytochrome c oxidase, pyruvate kinase and phosphoenolpyruvate carboxykinase enzyme activities; levels of protein carbonyls, malondialdehyde and 4-hydroxy-2-nonenal; lysosomal enlargement and membrane stability; intracellular neutral lipid accumulation; cell type composition and thinning of the digestive gland epithelium; and survival-in-air. Sex- and reproductive stage-related differences were found in bioaccumulation and in the values and responsiveness of most of the biomarkers. However, the patterns of sex-related differences were not consistent across all biomarkers. The differences in the biomarker responses between females and males also depended on the season, reflecting the progression of the gametogenesis cycle. Thus, selecting mussels of one specific sex does not seem to be a crucial requisite to carry out biomarker-based monitoring; yet, it is highly recommended to identify sex condition and gamete developmental stage of each mussel to test for the potentially confounding effects of sex, reproductive status and sex-related variability along the reproductive cycle.

Accumulation Characteristics, Tolerance Differences and Risk Assessment of Heavy Metals in Sugarcane

Seven varieties of sugarcane were grown on soil polluted with heavy metals, including Pb, Cd, and As. Sugarcane growth, the heavy metal contents in different sugarcane tissues, and the subcellular distributions of the heavy metals in the roots and leaves were analyzed. The purpose of this investigation was to study sugarcane growth tolerance, the accumulation of heavy metals and the mechanism of sugarcane tolerance to heavy metals at the subcellular level. Health risk assessments were performed according to the models recommended by the United States Environmental Protection Agency (US EPA). The patterns of heavy metal storage were demonstrated to differ among different tissues in all sugarcane varieties investigated. Most of the heavy metals that were absorbed accumulated in the roots of the sugarcane, and the heavy metals in the root cells were mostly located in the cell wall. The health risk index was used to analyze the juice and indicated that the consumption of sugarcane juice by adults and children posed no significant health risks. This study shows that sugarcane grown on heavy metal-contaminated farmland is safe for consumption. The results of this study revealed an important and positive implication regarding the cultivation of sugarcane on farmland that is polluted by heavy metals and the potential to simultaneously achieve sustainable economic output and potential environmental restoration.

Trace element accumulation potential in lemongrass varieties (Cymbopogon species) and prediction through regression model equations followed by path analysis: a field study

A field investigation was conducted to monitor the trace element accumulation pattern and potential in lemongrass varieties when cultivated in varying concentrations of tannery sludge contaminated soils. Regression model equations were developed to predict the trace elements concentration in lemongrass plant parts. Model efficiency values ranged between 0.53 and 0.85 for roots and 0.50 to 0.77 for shoots. R2 for all the equations was high and ranged between 0.52 and 0.95 for roots and 0.50 to 0.91 for shoots. Path analysis coefficients revealed the status of interdependence between soil properties and heavy metal concentrations in plant tissues and their translocation pattern in the same. TF > 1 for Ni and Pb was recorded in all test varieties at different tannery sludge concentrations in soil and for Cd in Suwarna variety grown in sole TS. BAF>1 and BAC>1 for Ni and Pb was observed for all test varieties. BCF>1 for Cr was found in Suwarna variety at sole tannery sludge. It can be concluded that lemongrass can accumulate lead and nickel in its harvestable plant parts. Hence, it can act as a suitable phytoextractor for the same metals. Range of essential oil content (percentage) varied in all test varieties i.e. Shikhar (1.04–1.29), Krishna (0.94–1.05), Suwarna (0.82–0.95) and Chirharit (0.87–1.06) at different tannery sludge concentrations. Moreover, heavy metal content in the essential oil of all test varieties was found to be within the permissible limits, hence cultivation of lemongrass can be recommended at metal contaminated sites with minimum risk of food chain contamination.

Metal pollution and its biological effects in swimming crab Portunus trituberculatus by NMR-based metabolomics

Metal pollution in the Bohai Sea in China has posed a potential risk on marine organisms. In this work, crabs (Portunus trituberculatus) were sampled from four sites, namely a reference (site 3934) and three metal-polluted (sites 6151, 6351, and 3562) sites, located in the Bohai Sea. Metal concentrations in crab gill tissues were measured using inductively coupled plasma mass spectrometry. Cu, Zn, and Cd in crab samples from S3562 presented the highest concentrations. Particularly, Cu concentration exceeded the marine biological quality standard II. Cd contents in crab samples from all metal-polluted sites exceeded the marine biological quality standard I. Nuclear magnetic resonance-based metabolomics indicated metal pollution-induced immune stresses in crab samples from all metal-polluted sites. Metal pollution in S6151 and S6351 disturbed energy metabolism through differential pathways. For crab samples from S3562, the metabolic profile suggested that metal pollution mainly induced osmotic stress.

Effects of iron oxide nanoparticles on Fe and heavy metal accumulation in castor (Ricinus communis L.) plants and the soil aggregate.

In this study, the effects of iron (Fe) nanoparticles (NPs) on Fe and heavy metal accumulations by castor (Ricinus communis L.) plants were investigated. The castor cultivar was planted in the soil contaminated with Pb and Zn for 48 days with Fe2O3 NPs treatments. The Fe and heavy metal concentrations in the plant tissues, the plant tissues' ultrastructures, and the Fe and heavy metal distributions in the soil aggregate were analyzed. The results of this study indicate that there is a mutual promotion relationship between Fe and heavy metals (Pb and Zn). The scanning electron microscopy (SEM) revealed ultrastructural differences in the xylem and phloem with Fe2O3 NPs addition, and the presence of Fe2O3 NPs may influence the synthesis of starch granules in response to heavy metal stress. Based on the analysis of the soil aggregate, α-Fe2O3 NPs and γ-Fe2O3 NPs changed the size distribution of the soil aggregate, that is, the macro-aggregate and the clay fraction contents increased and the micro-aggregate content decreased. Moreover, in the different size fractions of the soil aggregate, Fe2O3 NPs can change the Zn and Fe enrichment and migration between the macro-aggregate and clay fractions, and there is a synergistic effect between the Fe and Zn migration. In addition, in the castor organs (roots and shoots), the Zn accumulation was mainly determined by the Zn concentration of the macro-aggregate fraction, while the Fe accumulation was mainly determined by the Fe concentration of the micro-aggregate fraction. Overall, these direct observations help improve our understanding of the migration and transport characteristics of Fe and heavy metals in soil-plant systems when Fe nanoparticles are added to metal-contaminated soils.

Heavy metals in Bushmeat from New-Bussa and its environs, Nigeria

Bushmeat have provided complimentary protein for human population across the world over the centuries. This study assessed the concentration of heavy metals in bushmeats in New Bussa and its environs. Three carcass of bush meat (Kobus kob (Kob), Tragelaphus scriptus (Bushbuck) and Sylvicapra grimmia (Duiker)) were sourced from the study area. The carcass was digested and concentrations of nine heavy metals (Mn, Fe, Cu, Zn, Pb, Cr, Ni, Co and Cd) were determined using Atomic Absorption Spectrophotometer (AAS). Results obtained for the heavy metal analysis were subjected to one-way analysis of variance (ANOVA) while Pearson’s correlation was used to determine the relationship in the samples. The heavy metal concentration in muscle tissues of the selected bushmeat revealed that zinc with 815.00±13.00 mg/kg in Kob was the highest mean value of all meat samples, followed by Iron (479.00±10.00 mg/kg) in Duiker while Pb level in Bushbuck 213.00±3.00 mg/kg is outrageously the highest. Copper, Chromium and Nickel did not exceed the permissible limits as set by FEPA/WHO. The concentration pattern of heavy metals in bush meat show that Sylvicapra grimmia and Tragelaphus scriptus had the same pattern of Zn>Fe>Pb>Cr>Mn>Cu>Co>Ni>Cd concentration while Kobus kob pattern of association is Zn>Fe>Cr>Pb>Ni>Cu>Co>Cd>Mn. The comparative study of the heavy metal concentrations revealed that Zinc (Zn) recorded the highest frequency, followed by Iron (Fe) and Lead (Pb). This study has shown that high level of Pb in the samples from the study area is a matter of concern in bush meat consumption in the study area; hence people should be warned of impending danger in the consumption of heavy metals contaminated bush meat.
 Keywords: Bushmeat, heavy metals, concentration, toxicity, contaminated

Analysis of neuronal iron deposits in Parkinson's disease brain tissue by synchrotron x-ray spectromicroscopy

BackgroundNeuromelanin-pigmented neurons, which are highly susceptible to neurodegeneration in the Parkinson’s disease substantia nigra, harbour elevated iron levels in the diseased state. Whilst it is widely believed that neuronal iron is stored in an inert, ferric form, perturbations to normal metal homeostasis could potentially generate more reactive forms of iron capable of stimulating toxicity and cell death. However, non-disruptive analysis of brain metals is inherently challenging, since use of stains or chemical fixatives, for example, can significantly influence metal ion distributions and/or concentrations in tissues. AimsThe aim of this study was to apply synchrotron soft x-ray spectromicroscopy to the characterisation of iron deposits and their local environment within neuromelanin-containing neurons of Parkinson’s disease substantia nigra. MethodsSoft x-ray spectromicroscopy was applied in the form of Scanning Transmission X-ray Microscopy (STXM) to analyse resin-embedded tissue, without requirement for chemically disruptive processing or staining. Measurements were performed at the oxygen and iron K-edges in order to characterise both organic and inorganic components of anatomical tissue using a single label-free method. ResultsSTXM revealed evidence for mixed oxidation states of neuronal iron deposits associated with neuromelanin clusters in Parkinson’s disease substantia nigra. The excellent sensitivity, specificity and spatial resolution of these STXM measurements showed that the iron oxidation state varies across sub-micron length scales. ConclusionsThe label-free STXM approach is highly suited to characterising the distributions of both inorganic and organic components of anatomical tissue, and provides a proof-of-concept for investigating trace metal speciation within Parkinson’s disease neuromelanin-containing neurons.

Comparative assessment of biomarker response to tissue metal concentrations in urban populations of the land snail Helix pomatia (Pulmonata: Helicidae).

The traffic pressure is increasing, resulting in the emission of atmospheric pollution. Soil organisms will need to respond to pollution stressors. Among them, land snails are valuable indicators of ecosystem disturbance. In this study, land snails Helix pomatia were sampled from three city localities with different traffic intensity. Oxidative stress biomarkers catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR) and glutathione-S-transferase (GST) in the foot muscle (FM) and hepatopancreas (HP) tissue were determined. Also, five heavy metal (Cd, Cu, Ni, Pb, and Zn) concentrations were quantified in soil and tissue samples. According to the results, the highway induces the strongest contamination on the surrounding environment, with the highest metal concentrations measured in soil and snails. At the most polluted locality, only Cd exceeded some soil guidelines authorities that we referred to in this study. In addition, tissue Cd concentrations exceeded the United States Environmental Protection Agency (USEPA) value (1 mg kg-1) for soil invertebrate toxicity at all localities making it likely responsible for generating adverse effects in snails. Regarding HP, the CAT and GST are the most sensitive parameters that could be useful as oxidative stress biomarkers in snails exposed to the actual metals in the environment. On the other hand, in FM tissue, the most pronounced changes were recorded for GPX and GR. Based on tissue-specific enzyme responses, three urban populations were clearly separated. Therefore land snails are the promising candidates for quick field-based biomarker studies after showing a tissue-specific concentration-dependent induction of certain enzymes to heavy metals.

Heavy Metals Analysis of the Limpet Cellana Karachiensis (Winckworth 1930) from Two Rocky Shores of the Karachi Coasts of Pakistan

In current years, observing the concentration of heavy metals in marine biota has received much awareness as the public are more aware about the healthy environment and food. Intensity of these metals in a huge range of finfish and shellfish would give baseline information for some of the toxic metals. In the present investigation an attempt has been made to study the presence and concentration of some heavy metals in the true limpet Cellana karachiensis a gastropod mollusk which is abundantly found at the intertidal to high tidal zones of different rocky shores of Sind and Baluchistan coasts of Pakistan. In the present study two distinct anthropogenic dynamic rocky shores i.e., Clifton and Mubarak village of Karachi coast was selected to analyse the heavy metals in soft tissues of C. karachiensis which accept as a good bio-indicator mollusk to observe heavy metal pollution awareness. The concentration of zinc (Zn), chrome (Cr), copper (Cu), lead (Pb) and cadmium (Cd) in the soft tissue of the limpet C. karachiensis from two rocky shores in the Karachi coast has been measured by Atomic Absorption Spectrometer (A Analyst 700) for monitoring metal contamination of samples. Accumulation of Zn was found highest followed by Cr, Cu, Pb and Cd in the months of July and August 2019 in Clifton shores. While at the same period the highest concentration was Zn followed by Cu, Cd, Cr and Pb at Mubarak village shore. It has been observed that, C. karachiensis at Clifton shore accumulated more than heavy metals that found at Mubarak village shore. The pattern of accumulation of Heavy metals at both sites of limpets did not exhibit much difference. ANOVA single factor and student t test was done for the statistical analysis of metal contents in soft tissues of C. karachiensis of both shores at (p<0.01) and observed statistically significant differences in the amounts of the Cu, Cd and Zn elements among the limpets of both rocky shores. Same as the significant result at p<0.01 and p<0.05 was observed in between the length size of limpets at Clifton and Mubarak Village rocky shores. Correlation studies carried out for the metal concentrations in limpet and shell length of the animal which did not show significant results except Cu at Mubarak village shore. The results were compared with previous studies and discussed.

Heavy metal concentrations in tissues of marine fish and crab collected from the middle coast of Zhejiang Province, China.

Concentrations of the heavy metals As, Cd, Cu, Hg, Pb, and Zn in various tissues of five marine fish species and one crab species collected from the middle coast of Zhejiang Province of China were investigated in this study. The results indicated considerable variation in heavy metal concentrations in different tissues and species. Elevated concentrations of most heavy metals were identified in fish gills and crab gills and hepatopancreas, with some differences by heavy metal type. In addition, carnivorous and benthivorous fish species generally contained relatively high concentrations of heavy metals due to feeding habits and habitats. Geographical variations of heavy metal concentrations in muscle may be attributable to species-dependent differences and terrigenous contamination. The potential health risk assessment suggested that exposure doses of most heavy metals were safe for human consumption, with the exception of As.

Прижизненная оценка накопления тяжелых металлов в организме сельскохозяйственных животных (обзор)

In order to prevent the development of pathological processes in the body of farm animals, the intravital determination of the content of heavy metals in organs and tissues is relevant. The state of the solution to this problem is considered. A description is given of various approaches that allow testing the content of heavy metals in animals, assessing and adjusting the environmental safety of livestock products.

Development of fish age normalization technique for pollution assessment of marine ecosystem, based on concentrations of mercury, copper, and zinc in dorsal muscles of fish.

Correlation between metal concentrations in fish tissues and fish body size poses certain challenge when comparing concentration levels encountered at different locations or time periods by degrading performance of statistical tests due to variable age composition of fish sample pool. In order to overcome this, the concentrations of Hg, Cu, and Zn, measured in tissues of five fish species, were normalized to selected age group. Computed species-specific equations, based on empirically obtained exponential relationship, provided accurate estimates of the normalized concentrations under the conditions of substantial metal and fish age covariation. Obtained normalized and measured concentrations were then compared among sampling stations by means of commonly used analysis of variance (ANOVA) in combination with Tuckey's HSD test, where 11 out of 18 considered cases showed significant smoothing of the observed differences. The applied method worked well in the case of locally distributed coastal species populations where transformed data allowed clearer separation of spatial areas exhibiting different levels of pollution. At the same time, application of the method on pelagic fish species was less successful due to high mobility of specimens and mixed impact on the population originating from variable pollution levels at different areas of the entire migration region; therefore, attribution of a sample pool to a specific catchment area can cause a bias in assessment results.

A Preliminary Study of Heavy Metals in Thais gradata Collected from Kuala Sungai Ayam and Pantai Lido, Peninsular Malaysia

This study determined the levels of Cd, Cu, Fe, Ni, and Zn in the soft tissues, operculum and shells Thais gradata between Kuala Sungai Ayam and Pantai Lido, Peninsular Malaysia, collected in 2008. The metal concentrations (µg/g dry weight) in the soft tissues of T. gradata collected from the two sites in Peninsular Malaysia ranged from 3.01-4.72 for Cd, 83.96-124 for Cu, 345-365 for Fe, 6.80-14.8 for Ni, and 2916-4361 for Zn. Overall, this preliminary baseline data can be used for regular ecological monitoring for the effective management of the coastal area in Malaysia.

Toxic metals in the warty crab in the southern Black Sea: Assessment of human health risk

The present study was performed to assess Cd, Pb, and Hg contaminations and human health risk in the warty crab Eriphia verrucosa (Forskål, 1775) in Akliman shores of Sinop Peninsula of the Black Sea. Heavy metals analysis was performed by inductively coupled plasma mass spectrometry. Among studied toxic metals, Pb had the highest mean concentration in E. verrucosa. The highest mean concentration of Pb (0.2 mg per kg of wet weight) was observed in male samples of the warty crab. However, higher concentrations of Cd and Hg (0.11 and 0.019 mg per kg of wet weight, respectively) were observed in females of E. verrucosa. The mean Cd values found in the warty crabs were higher in May and June than those in July and August. On the other hand, Pb values were recorded in July and August. The mean Hg values were not different between months except July and August for male samples of E. verrucosa. Foraging seasons of these crabs are different, which can lead to differences in prey size and ultimately metals intake. However, the results show that a toxic heavy metal concentration in edible tissues of crab from the southern Black Sea was within the permissible limits given by national and international food codices. Target hazard quotient (THQ) for each metal and hazard index (HI) were calculated to evaluate non-carcinogenic human health risks. Estimated THQs of Cd, Pb, and Hg suggest that these metals in the warty crab do not pose any apparent threat to humans, when the HI value is below the value of 1. The result of the analysis has shown that the warty crab E. verrucosa can be used as bioindicator as it contains variable levels of the metals observed. Since consumption is the main source of heavy metal intake by humans, monitoring studies are needed to protect public health and take preventive measures.

Investigation of toxic elements in Carassius gibelio and Sinanodonta woodiana and its health risk to humans.

Increasing toxic metal content in aquatic products has become a universal burden due to the risks to aquatic organisms and human health associated with the consumption of these products. In this study, toxic metal distribution and accumulation in the organs of fish and bivalve species of economic and culinary importance from the lower reaches of the Yangtze River are examined, and the corresponding health risks are also investigated. In general, the viscera and gill show higher concentration of metals than other tissues. The order of the accumulation sequence of metals in muscle tissue of fish and bivalve is Zn > Cu > Mn > Cr > As > Hg > Pb > Cd and Mn > Zn > Cu > As > Cr > Pb > Cd > Hg respectively. Maximum accumulation of Mn (507.50μgg-1) and Pb (0.51μgg-1) in the gill tissues indicates the major uptake of these metals from the water column. According to the Hazard Index (HI) calculations (based on USEPA), the analyzed metals will not cause any harmful health effects to individuals for both normal and habitual fish consumers, except for Hg and As in habitual consumers, if these species are consumed at a larger amount. Compared to the Chinese Food Health Criterion and other international standards (WHO/FAO), metal concentrations in the edible muscle tissues of the studied species are lesser than the acceptable levels and found to be fit for human consumption.

Heavy Metals in Barnacles Balanus Sp.: From Biomonitoring to Coastal Management

This study determined the levels of Cd, Cu, Fe, Ni, and Zn in the soft tissues and shells of barnacles (Balanus sp.) collected from the Kuala Juru, Sebatu, Sg. Ayam and Kg. Pasir Puteh, Peninsular Malaysia, obtained in 2008. The metal concentrations (μg/g dry weight) in the soft tissues of Balanus sp. received from four sites in Peninsular Malaysia ranged from 2.93-4.17 for Cd, 20.2-92.5 for Cu, 480-1193 for Fe, 6.40-18.0 for Ni, and 224-414 for Zn. Based on the present data, the trace metal bioavailability’s to the Balanus in all the populations, especially in a known polluted site at Kg. Pasir Puteh is low. Overall, this preliminary baseline data can be used for regular ecological monitoring for the effective management of the coastal area in Malaysia.

Heavy metal concentrations in roadside plants (Achillea wilhelmsii and Cardaria draba) and soils along some highways in Hamedan, west of Iran.

The present study was conducted to analyze the effects of traffic volumes on Cd, Cu, Pb, Ni, and Zn contents in roadside soils and in two dominant herbaceous species (Achillea wilhelmsii and Cardaria draba) along highways and to evaluate the dynamic characteristics of these elements and their accumulation by the aerial parts and roots of these herbaceous species. The plant samples were collected along 700m of a 9-km segment of each of the three major highways in Hamedan Province (West Iran) with different traffic volumes: Hamedan-Goltapeh (HG), Hamedan-Razan (HR), and Hamedan-Kermanshah (HK). The results indicated that the mean contents of Cd, Cu, Pb, Ni, and Zn in the soil samples were 0.26, 18.74, 14.98, 18.21, and 62.25mgkg-1, respectively. Furthermore, the mean contents of elements (mgkg-1) in aerial parts of A. wilhelmsii were 0.16 for Cd, 4.52 for Cu, 1.91 for Pb, 1.70 for Ni, and 44.80 for Zn, while in the aerial part samples of C. draba, the concentrations (mgkg-1) and the mean contents were 0.16, 2.29, 2.58, 1.60, and 31.29, respectively. This meant that the traffic volume affected the contents of the metals in the soil and the herbaceous species. The metal content in herbaceous tissues varied significantly between plant species. A. wilhelmsii tended to accumulate the metals in the roots while C. draba retained them mostly in the aerial parts. The significant positive correlations of Cd, Cu, Ni, and Zn content in root and aerial parts of the herbaceous plant with those found in the soil samples showed the potential of the studied species for application in biomonitoring studies. Comprehensive analysis (effect of traffic volumes and relationships between the content of elements in plant tissues and soil samples) indicated that Cu in both herbaceous plants was mainly derived from soil, while A. wilhelmsii absorbed Cd and C. draba absorbed Zn mainly through the stomata from atmospheric depositions. Without considering atmospheric depositions due to intense traffic volumes, in A. wilhelmsii, the translocation factor (TF) values of Cu and Zn were 1.06 and 1.44, respectively and in C. draba, the TF values of Cd, Cu, and Pb were 1.06, 1.09, and 1.13, respectively, thus suggesting that both herbaceous species had high potentials for transferring metals from the roots to aerial parts.

Uptake and allocation of selected metals by dominant vegetation in Poyang Lake wetland: From rhizosphere to plant tissues

Wetland plants have shown much potential for the removal of metals from soils by accumulating in plant tissues. Therefore, analysis of the metal accumulation and translocation capabilities of wetland plants is important for effective phytoremediation of heavily polluted wetlands. However, few studies have been conducted to analyze metal accumulation in metal-contaminated wetlands of Poyang Lake, China. The aim of this study was to investigate the absorption and transportation characteristics of metals (Cr, Ni, Cu, Zn, Cd, Pb) in five dominant plant species (i.e. Phragmites australis (Cav.) Trin. ex Steu, Triarrhena lutarioriparia L Liu, Carex cinerascens Kukenth., Artemisia selengensis Turcz. ex Bess., Phalaris arundinacea Linn), in three wetlands of Poyang Lake (China). The pollution assessment indicated that the studied wetlands were all polluted by metals with PLI (pollution loading index) >1 and Cd was the main pollutant presenting a high ecological risk. The metal concentrations in different plant tissues did not exceed either the toxic critical values or the hyperaccumulation critical values. Bioaccumulation factor (BAF) and translocation factor (TF) were used to clarify the accumulation and translocation characteristics of metals by wetland plants. Triarrhena and Artemisia showed significantly high BAF values for Cd (8.26 and 4.31, respectively); this indicated their suitability and potential for Cd phytostabilization. The significantly high TF values of Cd (5.29) and Pb (3.25) in Phragmites indicated its ability for Cd and Pb phytoextraction. The high BAF and TF also indicated the high potential of Triarrhena, Artemisia and Phragmites as hyperaccumulators. The correlation analysis and multiple statistical analysis indicated that interactive effects of soil properties on metal accumulation are more significant than any single soil property, and influence of soil properties may partly depend on plant species. This study provides valuable information for phytoremediation of metal contaminated wetlands with suitable plant species.

Matching times: Trying to improve the correlation between heavy metal levels in mosses and bulk deposition.

The relationship between the concentrations of metals in moss tissues and atmospheric deposition is highly complex, resulting in a general lack of correlations between these two matrices. Here, we tried to improve the significance of the moss-bulk deposition (BD) relationship by eliminating the mismatch between the time that the moss tissue selected for analysis is exposed to atmospheric deposition, and the time during which BD is collected. For this, we analysed the concentrations of Cd, Hg and Pb in new grown tissue of Pseudoscleropodium purum and BD collected monthly, for one year, in 21 sampling sites (SS) under different degrees of pollution. Additionally, we assessed how different moss tissues, including native moss (green parts and new grown tissues of P. purum) and moss transplants of Sphagnum denticulatum, reflect BD to find out which moss tissues provide a better estimate of the atmospheric deposition of heavy metals. First of all, our results showed that eliminating the mismatch between native moss exposure time and BD collection period is not enough to improve their correlation. Environmental variation emerged as the main driver of tissue content variation altering the moss-BD relationship unpredictably. Secondly, native P. purum represents BD values better than devitalized transplants by displaying a greater number of significant correlations with BD. Specifically, green parts of P. purum generally represent better BD than new grown tissues. Overall, we conclude that neither native mosses nor transplants are good estimators of atmospheric heavy metal deposition rates. However, they are good qualitative indicators of the atmospheric deposition, by allowing us to differentiate SS subject to a wide range of pollution levels. Additionally, green parts of P. purum, and likely of other mosses with similar growth forms, should be used in passive biomonitoring studies to make results from different studies comparable.

Effect of biochar on yield and quality of tomato grown on a metal-contaminated soil

Metal contamination of soils is a main source of hazard materials in food chain. Biochar is a promising agriculture tool to improve plant yield and enhance quality of vegetable crops. Three rates of biochar (C = 0, BC1 = 5 and BC2 = 10 ton ha−1) were added to a metal-polluted soil before the cultivation of tomato (Solanum lycopersicum cv Super). The non-edible part of tomato accumulated 80 and 84 % of Cu and Zn, while 20 and 16 % was transferred to the fruit. Whereas the non-edible part of tomato kept 99.9 and 99.8 % of Pb and Cd, less than 0.1 and 0.2 % were moved to tomato fruit. Metal concentrations in tomato tissues as affected by biochar application found to decrease in the order: C > BC1 > BC2. BC1 and BC2 significantly increased the tomato fruit yield by 20 and 30 %, respectively, above C treatment. BC2 increased the total acidity, TSS, vitamin C and lycopene in the juice of tomato by 33, 29, 39 and 24 % compared to the control. Biochar increased essential nutrient availability and uptake and minimized those of the toxic element. For improve tomato quality and productivity, it is recommended to apply biochar to metal-contaminated soils.