Biological Concentration Factor Research Articles

Lead-induced modification of growth and yield of Linum usitatissimum L. and its soil remediation potential

This study was designed to evaluate the pre-reproductive and reproductive responses of Linum usitatissimum L. (flax, linseed plant) to different levels of Pb in the soil. Flax seeds were sown in garden soil-filled earthen pots and treated with three different levels of lead as lead chloride (150, 450, and 750 mg Pb kg−1 soil) except control, and each treatment was replicated three times. Growth and reproductive parameters and photosynthetic pigments were significantly reduced (p ≤ 0.05) for all treatments. Quantitatively, Chlorophyll b content decreased more than chlorophyll a and the amount of proline content in the leaves increased in lockstep with the increase of Pb levels in the soil. Pb was found in substantial amounts in the roots, shoots, and seeds. The pattern of Pb accumulation in different organs was root > shoot > seeds. Pb levels in seeds obtained from 750 mg Pb kg−1 soil-treated plants exceeded the permissible limits. Biological concentration factor (BCF), biological accumulation coefficient (BAC) and translocation factor (TF) values showed that roots of L. usitatissimum absorbed and accumulated a substantial quantity of Pb but translocated only a fraction of that to the shoots. Therefore, L. usitatissimum L. can be used in phytostabilization rather than phytoextraction of Pb.

An integrated geochemical and mineralogical investigation on soil-plant system of Pinus halepensis pioneer tree growing on heavy metal polluted mine tailing

ABSTRACT The plant species Pinus halepensis grows spontaneously on heavily polluted mine tailings dumps of Campo Pisano (Sardinia, southwestern Italy). The area is characterized mainly by Zn, Pb, and Cd. Sampling campaign was done, related to soils and plant materials (roots, barks, wood, and needles), aimed at evaluating the main mineralogical characteristics, metal content, plant accumulation, and translocation behavior. The polluted substrates were composed of pyrite, dolomite, calcite, quartz, gypsum, and barite with iron sulphate, and iron oxide. Zn ore minerals (smithsonite) and muscovite detected mostly in the deeper soil layers. Zn was the most abundant metal in the substrate as well as plant tissues. Roots accumulated high metal concentrations (664.65-2710 Zn, 58.39-735.88 Pb, and 4.86-11.02 mg kg−1 Cd) reflecting high metal contamination in soil. The biological accumulation and translocation values were reported below one for all plant tissues. Pb, Zn and Cd Translocation Factor (TF) in needles ranged 0.03-0.32, 0.03-0.19, 0.04-0.14. Biological Concentration Factor (BCF) estimated up to 0.17, 0.18, and 0.19, respectively. Results indicate that P. halepensis is an excluder, tolerates high Zn, Pb, and Cd concentrations, restricts their accumulation and translocation to the aerial parts and may be applied for long-term phytostabilization and revegetation processes in abandoned mine tailing sites.

Field assessment of trace element phytoextraction by different Populus clones established on brownfields in southern Quebec (Canada)

Fast-growing hybrid poplars have been tested for their potential to remove trace elements (TE) from polluted soil in several temperate regions. Despite their potential, they have rarely been tested in countries with a cold temperate climate. The current study screened four different Populus hybrids for phytoextraction of four TEs (i.e., As, Cu, Pb, and Zn) on an abandoned brownfield site in southern Quebec (Canada). The main results showed that under the current experimental conditions, the most important traits determining the actual phytoextraction rate are Biological Concentration Factor (BCF) and TE accumulation in the aboveground biomass, rather than biomass productivity. Although the overall performance of the chosen hybrids was rather poor, the presence of poplar stands enhanced the movement of mobile contaminants in soil, which led to an increase in their concentration in the root zone. This aspect suggests possible strategies for using these plants with high transpiration rates in future phytoremediation projects, including either possible rotation with more effective TE phytoextractor plants (e.g., hyperaccumulators) that can remove high TE amounts that have migrated from the deeper soil layers following poplar plantation, or phytostabilization.

Determining the Mobility of some Essential Elements in Saffron (Crocus sativus L.) by the Neutron Activation Analysis

The main purpose of this investigation is to evaluate the concentrations of six essential metals (Na+, Mg2+, K+, Ca2+, Fe2+ and Zn2+) in saffron and a farm soil using the neutron activation analysis (NAA) as a nuclear spectrometry method. The stratified random sampling method was used here. The NAA results showed the well uptake of Mg2+, K+, Ca2+, Fe2+, and Zn2+ in saffron, which is lower than the toxicity range. Based on the contamination factor and geoaccumulation index, soil contamination levels were determined uncontaminated by Zn, moderately contaminated by Na+ and Fe2+, and strongly contaminated by Ca2+, K+, and Mg2+. Results of the contamination degree and pollution load index indicated moderately/strongly soil contamination and a moderate geometric mean of the contamination index. The Na+ enrichment factor (EF) showed a minimal man-made impact on sodium enrichment. Saffron cultivation has likely caused more accumulations of Mg2+, K+, Ca2+, and Fe2+, as well as a considerable deficiency of Zn2+ in the soil, based on EFs. The biological concentration factor showed a significant zinc accumulation by the corm of saffron. There was well translocation from corm to all the aerial tissues for K+. Also, sodium adsorption ratio, exchangeable sodium percentage, pH, and electrical conductivity evaluated the non-salinity level of soil in all saffron farms.

Effects and mechanism of igneous rock on selenium in the tropical soil-rice system in Hainan Province, South China

To illuminate the migration and transformation of selenium (Se) in the igneous rock-soil-rice system, 285 pairs of rhizosphere soil and rice samples were collected from the granitoid and basalt areas in Hainan Province, South China. The contents of Se in soils derived from granitoid and basalt are, respectively, 0.19±0.12 mg/kg and 0.34±0.39 mg/kg, which are much higher than Se contents in granitoid and basalt. Selenium shows remarkable enrichment from granitoid and basalt to soils. The mobile fraction of Se in soils derived from granitoid is 0.0100±0.0034 mg/kg, which is significantly higher than that of basalt (0.0058±0.0039 mg/kg). Although soil derived from basalt shows higher Se contents, Se contents in rice samples, mobile fractions of Se in soils, and biological concentration factor (BCF) is similar or even lower than that from granitoid. Basalt consist of calcic plagioclase and pyroxene, and are much richer in Fe, Al, and Ca than granitoid. Correspondingly, the basalt-derived soils have higher goethite, hematite, kaolinite, cation exchange capacity (CEC) content, and higher pH than the granitoid-derived soils, which result in higher adsorption capacity for Se and relatively lower Se bioavailability. Soils derived from granitoid and basalt in tropical regions are beneficial to produce Se-rich rice.© 2022 China Geology Editorial Office.

Phytoremediation of Heavy Metals Using Spinach (Amarantus spinosa) Grown on Contaminated Soils

This work was designed to assess the phytoremediation ability of Spinach (Amarantus spinosa) grown on two different soils (contaminated soil obtained from Chalawa Industrial Estate, Kano, and control soil obtained from Biological Garden of Umaru Musa Yar’adua University, Katsina). Concentrations (mg/Kg) of Cr, Fe, Mn, Ni, Pb, and Zn were determined using atomic absorption spectrophotometry (AAS). Biological concentration factors (BCFs) and translocation factors (TFs) were calculated. The mean levels of metals obtained ranged widely from 0.23 mg/kg Ni to 1971.37 mg/kg Fe. Highest mean levels of Cr (97.74 mg/kg), Fe (1971.37 mg/kg), Mn (78.22 mg/kg), Zn (170.60 mg/kg) were contained in the leaf of the spinach samples, whereas Ni (1.98 mg/kg) and Pb (14.24 mg/kg) were contained in the root of the spinach samples. The results showed a significant level (p<0.05) of all the metals analysed in the spinach samples grown on the polluted soil compared with those grown on the control soils. Amongst the metals, Ni and Pb were found to have the lowest (0.50) and highest (7.57) BCF values respectively. The lowest and highest TF values were found to be on Cr (0.32) and Zn (1.17) respectively. Consequently, Higher BCF and TF values were found for Pb and Zn and this resulted in greater extraction ability of Pb and Zn. The spinach ability to extract Fe and Ni was found to be poor.

Lead, zinc tolerance mechanism and phytoremediation potential of Alcea rosea (Linn.) Cavan. and Hydrangea macrophylla (Thunb.) Ser. and ethylenediaminetetraacetic acid effect.

In this study, we aimed to elucidate the defense mechanism of Alcea rosea (Linn.) Cavan. and Hydrangea macrophylla (Thunb.) Ser. against the single and compound toxicity of lead (Pb) and zinc (Zn) along with the synergistic effect of ethylenediaminetetraacetic acid (EDTA) in accumulation of metals in these two species. The two plant species were subjected to single metal treatment (Pb 1000mgkg-1, Zn 600mgkg-1) and compound metal treatment (Pb 1000mgkg-1 + Zn 600mgkg-1) in a greenhouse. Besides, different levels of EDTA were applied (2.5, 5.0, and 10.0mmolkg-1) with compound metal treatment. Several physiological and biochemical parameters, including plant photosynthetic parameters, enzymatic antioxidant system, accumulation concentration of metals, and subcellular distribution were estimated. The results showed that the antioxidative enzymes, proline, root morphological changes, and metal localization all played important roles in resisting Pb and Zn toxicity. A notable difference was that Zn was concentrated in the roots (58.5%) of H. macrophylla to reduce the damage but in the leaves (38.5%) of A. rosea to promote photosynthesis and resist the toxicity of metals. In addition, Zn reduced the toxicity of Pb to plants by regulating photosynthesis, Pb absorption and Pb distribution in subcells. The biological concentration factors (BCF) and translocation factors (TF) for Pb in two plants were less than 1, indicating that they could be considered as phytostabilizators in Pb-contaminated soils. Moreover, EDTA could enhance the enrichment and transport capacity of Pb and Zn to promote the phytoremediation effect. In summary, both plants have a certain application potential for repairing Pb-Zn-contaminated soil.

Heavy Metal Effects on Biodiversity and Stress Responses of Plants Inhabiting Contaminated Soil in Khulais, Saudi Arabia.

Simple SummaryDespite its high organic matter content, sewage sludge contains significant quantities of heavy metals, including those designated as hazardous, such as cadmium, nickel, chromium, mercury, copper, lead, and zinc, which, as a consequence, have a negative impact on living organisms. The current research sought to study the effect of dumping sludge, as one of the sources of pollution with heavy metals, on biodiversity and to assess the bioremediation and stress defense strategies of a tolerant plant species. The obtained results showed that soil pollution by heavy metals has a substantial influence on plant diversity. The selected species, Amaranthus retroflexus L., showed a high biological concentration factor (BCF) and low translocation factor (TF) for Cu, As and Ni. The stress defense strategies of A. retroflexus grown under complex heavy metals contamination are studied and discussed.Accumulation of heavy metals in soil is becoming an increasingly serious eco-environmental problem. Thus, investigating how plants mitigate heavy metal toxicity is necessary to reduce the associated risks. Here, we aimed to assess the bioremediation and stress defense strategies of tolerant plant species grown under complex heavy metals contamination. To this end, a field study was conducted on the vegetation cover of sites with different soil pollution levels. Forty-two plant species that belong to 38 genera and 21 families were identified. The pollution had a significant impact on plant richness in the polluted sites. Out of several screened plants, Amaranthus retroflexus L. was selected because of its high relative density (16.7) and a high frequency (100%) in the most polluted sites. The selected species showed a high biological concentration factor (BCF) and low translocation factor (TF) for Cu, As and Ni. To control the heavy metal-induced oxidative damage, A. retroflexus invested in detoxification (metallothionein and phytochelatins, glutathione and glutathione-S-transferase (GST). At the organ level, oxidase damage (H2O2, lipid and protein peroxidation) was observed, particularly in the roots. To mitigate heavy metal oxidative stress, antioxidant mechanisms (e.g., tocopherols, glutathione, peroxidases, catalase, peroxide dismutase and ASC-GSH cycle) were upregulated, mainly in the roots. Overall, our results suggested the potentiality of A. retroflexus as a promising bioremediatory and stress-tolerant plant at the same time; moreover, defense and detoxification mechanisms were uncovered.

Uptake of some heavy metal(oid)s by sunflower

Plant parts of sunflower (Helianthus annuus L.): root, stem, leaf, and seed, as well as the soil on which this plant culture was grown were analyzed for the content of As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn using Optical emission spectrometry with inductively coupled plasma (ICP-OES). The samples were prepared by wet digestion. To assess the degree of bioaccumulation in plant parts and the translocation of the examined elements from the roots to the above-ground plant parts, the Biological Concentration Factor (BCF), Mobility Ratio (MR), and Translocation Factor (TF) were calculated. BCF and MR values are less than 1 for all elements while TF (leaf/root) values for As, Cd, Cu, Fe, and Mn and TF (stem/root) values for Cu are higher than 1.

Ecological assessment of heavy metals accumulation in sediments and leaves of Avicennia marina along the Diu coast of the northeast Arabian Sea

The Coastal region of Diu is the natural habitat dominated by Avicennia marina mangrove species at the southeast coast of Saurashtra in Gujarat state of India. However, Diu being a famous industrial and tourism place survival of these mangrove species is threatened due to anthropogenic activities. In present studies, sediment and leaf samples of A. marina were collected from the Diu coast to evaluate the ecological threat of heavy metals accumulation in the marine habitat. There was remarkable presence of heavy metals such as copper, nickel, cadmium, chromium and lead in sediments and leaf samples of A. marina. The values of Biological concentration factors (BCFs) of heavy metals in leaf samples were high for cadmium, chromium and lead which suggest chelation of these heavy metals with biomolecules. The geo-accumulation index suggested that Site-4 and Site-5 were heavily contaminated with copper and nickel. The ecological risk index suggested that there is no significant effect of heavy metals on growth of plants in the mangrove ecosystem. Principal component analysis revealed that the samples collected from the natural habitats (Site-4 and Site-5) near the fishing and industrial areas were the main sources of heavy metal contamination. Hence, it was concluded that the concentration of heavy metals in the studied ecosystem had limited impact on growth of plants at Site-1, Site-2 and Site-3. However, growth of plants at Site-4 and Site-5 were threatened due to the toxic effect of copper and nickel present in its sediments.

Greenhouse Characterization of Inorganic Mercury, Methyl Mercury and Ethyl Mercury Migration and Transformation in Indian Mustard and Chinese Pakchoi

Soil mercury (Hg) contamination has long been a problem that threatens the environment and organisms. Thus, exploring the migration and transformation of Hg from soil to vegetable is vital. In this study, different Hg solutions were employed in greenhouse experiments. The Hg contents in soil and vegetable samples were determined by inductively coupled plasma – mass spectrometry. The results showed that the Hg accumulation depended on its concentration and form. A greater accumulation of inorganic Hg was observed in the roots (2.2–27.4 mg/kg) than in the aerial parts (0.6–6.0 mg/kg). A similar trend was also found in the methyl mercury (MeHg) and ethyl mercury (EtHg) irrigated groups. The MeHg contents were 0.7–8.0 μg/kg in roots and 0.1–3.7 μg/kg in aerial parts. The EtHg concentrations were 0.5–3.3 μg/kg in roots and 0.3–1.1 μg/kg in aerial parts. The translocation factors of inorganic Hg and organic Hg for both vegetables in most treatments were less than 0.5, which suggested that Hg primarily accumulated in the roots. The biological concentration factors of inorganic Hg were less than 0.4, and those for MeHg and EtHg were between 0.4 and 0.95, which indicated that the vegetables were more likely to absorb organic Hg from the soil. The methylation of inorganic Hg occurred in the roots. The potential hazards of Hg on food safety and human health must be considered in regions with serious Hg pollution.

Some Biogeochemical Characteristics of the Trace Element Bioaccumulation in the Benthic Fauna of the Piip Volcano (The Southwestern Bering Sea)

The Piip Volcano is a submarine volcanic edifice occupying the central part of the Volcanologists Massif in the southwestern Bering Sea, with two tops, southern and northern. The minimum depth of the northern top is located at 368 m, and of the southern at 464 m. Active hydrothermal venting occurring at both summits of the volcano supports diverse biological communities, including animals specific for chemosynthetic habitats. In benthic organisms inhabiting the northern and southern tops of the Piip Volcano, for the first time, we examined distribution patterns of the following trace elements: titanium, vanadium, chromium, manganese, iron, nickel, copper, zinc, arsenic, selenium, zirconium, molybdenum, silver, cadmium, antimony, barium, tungsten, lead, bismuth, and uranium. The element contents were quantified by the ICP-MS. Total carbon (TC) and total inorganic carbon (TIC) were determined using a Shimadzu TOC-L-CPN and mineral composition of sediment was determined using the XRD. In the water of the biotope from the northern top, concentrations of Mn, Zn, Ag, Cd, Sb, W, Pb were 2–6 times, and Ba was 50 times higher than those from the southern top. This was attributed to the lower temperature of fluids emanating at the southern top. An abundant population of Calyptogena pacifica (Bivalvia: Vesicomyidae: Pliocardiinae) was found only at the southern top. The main target of most trace elements, such as Fe, V, Cr, Co, Ni, Zn, As, Mo, Ag, Cd, W, Pb, Bi, and U were the soft parts of Calyptogena pacifica (with high TOC content, on average 53.1% in gills and 49.6% in the rest of the body). Gills were characterized by particular high contents (>100 µg g−1 dry w.) of Zn, Cd, Fe, Ni, Cu, and Pb, which can form sulphides or be associated with them. Shells of C. pacifica, as well as Brachiopoda, were depleted in these elements, as well as tissues of the carnivores Paguridae (Crustacea) and Actiniaria (Anthozoa). In suspension feeders from both tops, the lower contents of most elements were detected. Estimation of Biological Concentration Factor (BCF) for most elements varied from 102 to 104, reaching n105 for Ni, Zn, Ag, Cd, and Pb. A significant difference in BCF values between Fe and Mn was revealed.

Microplastic contamination assessment in water and economic fishes in different trophic guilds from an urban water supply reservoir after flooding

Rain and floods events are responsible for the transport of microplastics in freshwater ecosystems, yet to date, rare study has examined microplastics pollution in urban water supply reservoirs during such events. In this study, we investigated the concentrations and characteristics of microplastic in water and economic fish species with different feeding guilds in the Dafangying Reservoir, an important source of drinking water for Hefei city. Microplastic concentrations in water were relatively higher than that in natural lakes, indicating abundant microplastic contaminants input through overland runoff triggered by flooding. Our results detected five types (fiber, debris, film, microbead and particle) and six colors (black, transparent, blue, yellow, red and green) of microplastics in water samples. Fiber accounted for the dominant shape, which may result from the household sewage from washing clothes and desquamated fiber transported by wind and overland runoff. Meanwhile, transparent was the predominant microplastic color, which can be ascribe to the widely use of intentionally manufactured transparent disposable plastic commodities in cities. Then in fish samples, the microplastic concentrations ranged from 8.75 to 51.3 items/individual in fish guts, and 9.5–52.6 items/individual in fish gills. Our results demonstrated significant higher microplastic concentrations in planktivorous and herbivorous species. The filter feeding capture mode, i.e., engulfing floating prey through frequently drawing in large volume of water confused with microplastics, may result in the higher microplastic concentrations of planktivorous fishes. Due to the dense microplastics adhering on plant surface, herbivorous fishes can concentrate higher microplastics abundance through the ingestion of macrophytes. According to the biological concentration factor (BCF), all the determined microplastics gave BCF far below 1, suggesting the low bioaccumulation capacity of microplastics in fish species.

Physiological and biochemical responses of Lawsonia inermis L. to heavy metal pollution in arid environments

Trace metal pollution is increasing worldwide due to human activities. In this study, we investigated the physiological and biochemical effects of heavy metals on henna plants (Lawsonia inermis L.) grown in oases situated at various distances from an industrial complex in arid southern Tunisia. Our results showed that leaves had higher mean Zn and Cu concentrations than roots, while the reverse was true for Pb and Cd. Such metal immobilization in root cells is related to an exclusion strategy. The biological concentration factor (BCF) of Cu was > 1 at all studied sites, indicating the potential of henna plants to accumulate Cu from the soil. Heavy metals affected various physiological parameters of henna, including water status, macronutrient content, and photosynthetic activity, and increased the rate of hydrogen peroxide (H2O2) production and lipid peroxidation in leaves and roots, indicating oxidative stress. Deleterious heavy metal effects induced biochemical mechanisms in henna plants by accumulating proline and soluble sugars and activated the antioxidant system by enhancing the activities of superoxide dismutase, catalase, and glutathione peroxidase. The magnitude of accumulation and activation was proportional to the concentration of heavy metals in the plant tissues. The stimulation of enzymatic and non-enzymatic antioxidant systems reflects the ability of henna plants to survive in highly polluted environments.

Effects of Antimony Stress on Growth and Physiology of 10 Genotypes of Catalpa bungei

Increasing levels of antimony (Sb) pollution have been recognized as an emerging environmental problem. Phytoremediation of Sb-contaminated soil is a green, economical, and effective method for restoring polluted soils. Here, we studied differences in Sb tolerance, accumulation, and transport by different genotypes of Catalpa bungei C. A. Mey, with the goal of identifying genotypes that are suitable for remediating Sb-contaminated soil. Different concentrations of Sb were applied to soil, and we analyzed variation in growth, biomass, Sb content in different organs, Sb transport capacity, oxidizing substances, antioxidants, and antioxidant enzyme activities in 10 C. bungei genotypes. Marked differences were found in plant height, ground diameter, and biomass among different genotypes at given Sb concentrations. The Sb concentration in different plant organs also varied between genotypes. The content of Sb in each genotype was proportional to the exposure. At 600 mg Sb/kg soil, the highest concentration of Sb in roots and leaves was found in Genotype 63, and that in stems was found in Genotype 8402. The lowest concentration of Sb in roots, stems, and leaves was found in Genotypes 8402, 2-8, and 20-01, respectively. At 1200 mg Sb/kg soil, Genotype 5-2 had the highest concentration of Sb in roots, and Genotype 1-1 had the highest concentration in stems and leaves. The lowest concentration of Sb in roots was in Genotype 72, and that in stems and leaves was found in Genotype 20-01. At 2000 mg Sb/kg soil, the highest concentration of Sb in roots was found in Genotype 5-8, in stems in Genotype 8402, and in leaves in Genotype 72. The lowest concentration of Sb in roots was observed in Genotype 72 and in stems and leaves in Genotype 2-8. After absorption by C. bungei, Sb mainly accumulated in the roots, and upward transfer ability was poor. The Sb biological concentration factor of roots of all genotypes was >1 at each tested Sb concentration. Our results demonstrate that all 10 C. bungei genotypes could be used for plant stabilization of Sb-contaminated soil. However, the different genotypes of C. bungei had different responses to different Sb concentrations. Based on root Sb accumulation values, at soil Sb concentrations around 600 mg/kg, Genotypes 1, 63, and 5-8 are suited to phytoremediation; Genotypes 5-8, 1, and 5-2 are suited to phytoremediation at soil Sb concentrations around 1200 mg/kg; and Genotypes 5-8, 1, and 8402 are suited to phytoremediation at soil Sb concentrations around 2000 mg/kg. We demonstrate for the first time that Sb-contaminated soil can be improved by using specific plant genotypes tailored to different levels of Sb pollution.

Effects of Cattails and Hydraulic Loading on Heavy Metal Removal from Closed Mine Drainage by Pilot-Scale Constructed Wetlands

This study demonstrated heavy metal removal from neutral mine drainage of a closed mine in Kyoto prefecture in pilot-scale constructed wetlands (CWs). The CWs filled with loamy soil and limestone were unplanted or planted with cattails. The hydraulic retention time (HRT) in the CWs was shortened gradually from 3.8 days to 1.2 days during 3.5 months of operation. A short HRT of 1.2 days in the CWs was sufficient to achieve the effluent standard for Cd (0.03 mg/L). The unplanted and the cattail-planted CWs reduced the average concentrations of Cd from 0.031 to 0.01 and 0.005 mg/L, Zn from 0.52 to 0.14 and 0.08 mg/L, Cu from 0.07 to 0.04 and 0.03 mg/L, and As from 0.011 to 0.006 and 0.006 mg/L, respectively. Heavy metals were removed mainly by adsorption to the soil in both CWs. The biological concentration factors in cattails were over 2 for Cd, Zn, and Cu. The translocation factors of cattails for all metals were 0.5–0.81. Sulfate-reducing bacteria (SRB) belonging to Deltaproteobacteria were detected only from soil in the planted CW. Although cattails were a minor sink, the plants contributed to metal removal by rhizofiltration and incubation of SRB, possibly producing sulfide precipitates in the rhizosphere.

Ex situ phytoremediation trial of Sardinian mine waste using a pioneer plant species

The mitigation of metals contamination is currently a crucial issue for the reclamation of mine sites. Indeed, mine wastes are often disposed in open dumps and consequently pollutants are subjected to dispersion in the surrounding areas. In this study, the potential use of Helichrysum microphyllum subsp. tyrrhenicum for phytostabilization was evaluated in ex situ conditions. Ninety specimens were randomly selected and were planted in three substrates (reference substrate, mine waste materials, and mine wastes with compost). Mineralogical compositions of substrates, rhizosphere, and roots were assessed through X-ray diffraction (XRD). Zn, Pb, and Cd concentrations of substrates, rhizosphere, soil pore waters, and plant tissues were determined. The phytostabilization potential was determined through the application of biological accumulation coefficient (BAC), biological concentration factor (BCF), and translocation factor (TF). Moreover, survival and biometric parameters were assessed on plant specimens. The polluted substrates and related rhizosphere materials were mainly composed of dolomite, quartz, pyrite, and phyllosilicate. Zn was the most abundant metal in substrates, rhizosphere, and soil pore waters. XRD analysis on roots showed the presence of amorphous cellulose and quartz and Zn was the most abundant metal in plant tissues. H. microphyllum subsp. tyrrhenicum restricts the accumulation of the metals into roots limiting their translocation in aereal parts, indicating its potential use as phytostabilizer (BCF, BAC, TF < 1). Survival and growth data showed a great adaptability to different substrates, with an evident positive effect of the implementation of compost which increased the plant survival and decreased the metals uptake into roots.

Biochemical transmutation in Lumbricus terrestris and phytoextraction of heavy metals from the swamp of Challawa industrial layout, Kano, Nigeria

Discharge of untreated industrial effluents has been associated with soil contamination. Biochemical alterations in Lumbricus terrestris and remediation capacity of Azadirachta indica tree from industrial effluent discharge locations in Challawa (A and B) and Kura village (control location C) were assessed. Levels of nitrate, phosphate, iron, chloride, and hardness at locations A and B were significantly (p < 0.05) higher than those at location C, but their sulfate concentrations were significantly (p < 0.05) weaker. pH and magnesium concentration at location A were significantly higher than those at locations B and C. Levels of Fe, Cu, Zn, Pb and Mn in soils at the discharge locations were significantly (p < 0.05) higher than those of C. Azadirachta indica tree (AIT) had a translocation factor (TF) > 1 for Pb and Zn, while its biological concentration factor (BCF) was > 1 for Fe. Values of biological accumulation coefficient (BAC) for AIT and soil contamination factor (CF) were < 1 for the metals. Bioindicators of oxidative stress (MDA, GST, CAT and SOD) in earthworm supernatants from the discharge locations were significantly higher (p < 0.05) compared to that at location C, while their GSH levels were significantly (p < 0.05) lower. Acetylcholinesterase (AChE) activity in earthworm supernatants from discharge locations was significantly lower (p < 0.05) in comparison with the control. Trends in results revealed that AIT may be useful for extraction and stabilization of heavy metals in polluted soils. Also, the biochemical alterations in L. terrestris may serve as sensitive bioindicators of soil contamination.

Accumulation of Potentially Toxic Elements in Viola L. (Sect. Melanium Ging.) from the Ultramafic and Non-ultramafic Soils of the Balkan Peninsula

The aim of the present study was to assess the metal concentrations in five species of the genus Viola L. (section Melanium) from 12 ultramafic outcrops and two non-ultramafic (prolluvium and dolomite) soils from Serbia and Bosnia and Herzegovina. The concentrations of P2O5, K2O, Ca, Mg, Fe, Mn, Zn, Cu, Cr, Co, Cd and Pb in soils and plant samples, as well as their shoot-to-root ratio, biological concentration and accumulation factors were determined. Five investigated Viola species growing on 14 different localities displayed considerable differences in concentration of potentially toxic elements in their roots and its accumulation in their shoots. Viola kopaonikensis and V. beckiana from ultramafic soils could be classified as strong Ni accumulators, since moderately high level of Ni was measured in their shoots (up to 266 mg kg−1 and 337 mg kg−1, respectively), while in V. tricolor high amount of the same element was accumulated in the roots (up to 395 mg kg−1). Population of V. beckiana from dolomitic site in Bosnia and Herzegovina accumulated high concentrations of Pb in the shoots (67.1 mg kg−1), as well as of Cd in both roots and shoots (81.1 mg kg−1 and 60.5 mg kg−1). The results also suggest that V. kopaonikensis populations from the ultramafic soils of Serbia emerge as Cr accumulators, which is quite rare trait within the genus Viola. It seems that species from Melanium section apply quite different strategies against toxic elements. Future studies should strive to explain what adaptive mechanisms are hidden behind it.

Toxicity effects of procymidone, iprodione and their metabolite of 3,5-dichloroaniline to zebrafish

Dicarboximide fungicides mainly including procymidone, iprodione, vinclozolin, and dimethachlon are often applied as protective fungicides, 3,5-dichloroaniline (3,5-DCA) is their common metabolite in plant and environment. In this study, the acute toxicity of procymidone, iprodione and their metabolite of 3,5-DCA toward zebrafish was evaluated by semi-static method. The enrichment and metabolism of procymidone and iprodione in zebrafish were also clarified. The results indicated that procymidone and iprodione exhibited moderately toxic to adult zebrafish with the LC50 of 2.00 mg/L, 5.70 mg/L at 96 h. Both procymidone and iprodione could be metabolized to 3,5-DCA in zebrafish, which showed higher toxic to adult zebrafish with the LC50 of 1.64 mg/L at 96 h. From the perspective of histomorphology, for all treatment groups, the brain of the zebrafish was significantly damaged, while the damage to gut and gills was lighter. For procymidone, the biological concentration factor (BCF8d) were 236 and 246 at the exposure concentration of 0.2 mg/L and 0.04 mg/L, and the BCF8d were 3.2 and 2.4 for iprodione at the exposure concentration of 0.5 mg/L and 0.1 mg/L. Therefore, the procymidone and iprodione were moderate-enriched and low-enriched in zebrafish, respectively.