High Bioaccumulation Capacity Research Articles

Multiple pathway exposure risks and driving factors of heavy metals in soil-crop system in a Pb/Zn smelting city, China

Heavy metals (HMs) in soil near metal smelting areas have attracted great interest due to their crucial threat to agricultural product safety and human health. We investigated HMs in agricultural soils and crops (wheat and maize) in a Pb/Zn smelting city, central China; analysed the exposure risk of HMs through multiple pathways in a soil-crop system through Monte Carlo simulations; and identified the key driving factors using random forest (RF) model. The results showed that most soil HMs exceeded their background level. Cd had the highest exceeding rate compared with the screening values and the highest exceeding rate (40%, in wheat) compared with the food safety limit. Additionally, Cd had the highest bioaccumulation capacity in both maize and wheat. In identifying the key driving factors of soil HMs, RF had a satisfactory prediction performance for As, Cd, and Pb, with corresponding R2 values of 0.47, 0.51, and 0.60, respectively, with the dominant factors being distance to the Pb/Zn smelter, coal washery, and road area, respectively. However, Cr and Hg exhibited lower R2 values which may be due to their limited influence from the selected anthropogenic, traffic, and industrial variables. Probabilistic health risk assessments through Monte Carlo simulations revealed that the non-carcinogenic risk was around the risk limit (HI = 1), while the carcinogenic risk for both children and adults exceeded the risk limit (TCR = 1E-04), and adults had higher carcinogenic risk than children, which was due to a longer duration of exposure and higher ingestion rate of crop grains in adults. Cd had the highest carcinogenic risk and the highest probability of exceeding the limiting risk. Briefly, levels of Cd in both soil and crops should be controlled, especially for the source of smelting emissions. The results of this study could be treated as valuable references for policymakers to formulate control strategies for soil HM pollution in agricultural areas near Pb/Zn smelting activities.

Biomonitoring potentially toxic elements in atmospheric particulate matter of greater Dhaka region using leaves ofhigher plants.

In this study, four different plant species, namely Artocarpus heterophyllus, Mangifera indica, Psidium guajava, and Swietenia mahagoni, were selected from seven different locations to assess the feasibility of using them as a cost-effective alternative for biomonitoring air quality. Atmospheric coarse particulate matter (PM10), soil samples, and leaf samples were collected from residential, industrial, and traffic-congested sites located in the greater Dhaka region. The heavy metal concentrations (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in the leaves of the different species, PM10, and soil samples were analyzed. The highest Pb (718ng/m3) and Zn (15,956ng/m3) concentrations were found in PM10 of Kodomtoli which is an industrial area. On the other hand, the highest Fe (6,152ng/m3) and Ni (61.1ng/m3) concentrations were recorded in the PM10 of Gabtoli, a heavy-traffic area. A significant positive correlation (r = 0.74; p < 0.01) between Pb content in plant leaves and PM fraction was found which indicated that atmospheric PM-bound Pb may contribute to the uptake of Pb by plant leaves. The analysis of the enrichmentfactor (EF)revealed that soils were contaminated with Cd, Ni, Pb, and Zn. The abaxial leaf surfaces of Psidium guajava growing at the polluted site exhibited up to a 40% decrease in stomatal pores compared to the control site. Saet's summary index (Zc) demonstrated that Mangifera indica had the highest bioaccumulation capacity. The metal accumulation index (MAI) was also evaluated to assess the overall metal accumulation capacity of the selectedplants. Of the four species, Swietenia mahagoni (3.05) exhibited the highest MAI value followed by Mangifera indica (2.97). Mangifera indica and Swietenia mahagoni were also found to accumulate high concentrations of Pb and Cr in their leaves and are deemed to be good candidates to biomonitor Pb and Cr contents in ambient air.

Is the trend toward a sustainable green synthesis of copper oxide nanoparticles completely safe for Oreochromis niloticus when compared to chemical ones?: using oxidative stress, bioaccumulation, and histological biomarkers.

Scientists worldwide have noticed that cutting-edge technologies can be used to produce nanoparticles (NPs) in a sustainable and environmentally friendly way, instead of the old methods. However, the effectiveness of this approach for aquatic environments and species still needs to be determined. Therefore, this study aims to compare between the toxicity of green and chemically synthesized copper oxide nanoparticles (GS and CS) CuO NPs at two different concentrations on Nile tilapia (Oreochromis niloticus) using various biomarkers. CuO NPs' formation was proved, and their different characterizations were recorded. Then, the fish samples were randomly allocated in glass aquaria into five groups: one acted as a control group, and the other groups were exposed to two concentrations (25 and 50mg/L) of GS-CuO NPs and CS-CuO NPs, separately, for 4days. After the experimental time, in all groups that were exposed to two concentrations of both synthesized CuO NPs, the results revealed that glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), and thiobarbituric acid reactive substances (TBARS) levels were elevated in the liver and gills compared to glutathione reduced (GSH) content, which showed a significant decline. Bioaccumulation of Cu was more prevalent in the liver than in the gills, and the highest bioaccumulation capacity was more evident in the groups exposed to CS-CuO NPs. Moreover, the bioaccumulation of Cu caused severe histological changes in the liver and gills. In conclusion, the results suggested that GS-CuO NPs revealed less toxicity than CS-CuO NPs to the examined fish. However, they are still toxic, and their toxic effect cannot be overlooked.

BDE-209 exposure in murine melanoma (B16–F1) cells modulates tumor malignancy and progression in vivo

Melanoma is a type of skin cancer considered aggressive due to its high metastatic ability and rapid progression to other tissues and organs. BDE-209 (2,2′,3,3′,4,4′,5,5′,6,6′-decabromodiphenyl ether) is an additive used as a flame retardant and classified as a persistent organic pollutant that has a high bioaccumulation capacity due to its lipophilic nature. This substance has already been detected in rivers, air, soil, plants and even in different human biological samples, such as plasma, umbilical cord blood and breast milk, revealing a great concern to human populations. Thus, in the current study we investigated whether prior exposure of murine melanoma B16–F1 cells to BDE-209 modulates in vivo progression and malignancy of melanoma. B16–F1 cells were cultured and exposed in vitro to BDE-209 (0.01, 0.1 e 1 nM) for 15 days and then inoculated, via caudal vein, in C57BL/6 mice for experimental metastasis analysis after 20 days. Inoculation of BDE-209-exposed cells resulted in 82% increase of metastasis colonized area in the lungs of mice, downregulation of tumor suppressors genes, such as Timp3 and Reck, decrease of lipid peroxidation and increase of systemic and local inflammatory response. These findings are related to melanoma progression. Additionally, the histopathological analysis revealed greater number of focal points of metastases in the lungs and invasiveness of metastases to the mice brain (89%). The results showed that exposure to BDE-209 may alter the phenotype of B16–F1 cells, worsening their metastatic profile. Current data showed that BDE-209 may interfere with the prognosis of melanoma by modulating cells with less invasiveness capacity to a more aggressive profile.

Determination of 15 halogenated polycyclic aromatic hydrocarbons in aquatic products by stable isotope dilution coupled with gas chromatography-triple quadrupole mass spectrometry

Halogenated polycyclic aromatic hydrocarbons (H-PAHs), including chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs) and brominated polycyclic aromatic hydrocarbons (Br-PAHs), are compounds in which one or more hydrogen atoms replaced by chlorine or bromine atoms. These compounds are not only difficult to degrade but also highly fat soluble and toxic. They are a new type of high-risk organic pollutants with structures similar to those of dioxins, and their toxicity is even higher than that of the parent polycyclic aromatic hydrocarbons (PAHs). The bioaccumulation of H-PAHs can be predicted by their octanol-water partition coefficient (Kow); in general, higher bioaccumulation capacity and Kow values indicate greater fat solubility. Therefore, animal-derived foods with higher fat contents, such as animal meat, milk, aquatic products, and their processed forms, are more likely to be contaminated with higher contents of H-PAHs than those with lower fat contents. In this work, a gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) method coupled with stable isotope dilution was established to determine 15 H-PAHs in aquatic products. The instrument and pretreatment methods were systematically optimized. The GC-MS/MS used in this method can effectively eliminate matrix interferences and features high sensitivity and low analytical cost; thus, it has good application prospects. The samples were added with an isotope internal standard before extraction to calibrate the loss of the tested substance during the pretreatment process, extracted by accelerated solvent extraction, purified using gel permeation chromatography and PRiME HLB columns, and then analyzed by GC-MS/MS. The use of two DB-5MS chromatographic columns (30 m×0.25 mm×0.25 μm) and microplate fluidics technology to connect chromatographic columns 1 and 2 in series led to better separation effects, good peak shapes, and high target compound responses. The 15 H-PAHs demonstrated good linearities in the range of 1-50 μg/L, with correlation coefficients (r) greater than or equal to 0.993. The relative standard deviation (RSD) values of the relative response factor (RRF) of the H-PAHs were less than 9%, the method detection limit (MDL) was 0.009-0.072 μg/kg, and the method quantification limit (MQL) was 0.031-0.240 μg/kg. Three spiked levels of 0.25, 1.0, 2.5 μg/kg were added to the blank samples to determine the recovery and precision. The recoveries for these spiked levels were 74.6%-116.8%, 77.8%-123.2%, and 71.9%-124.8%, respectively, and the corresponding RSDs were 0.6%-8.2%, 0.6%-9.0%, and 0.4%-10.6%, respectively. The total actual content of H-PAHs in aquatic product samples was 0.60-3.54 μg/kg. Among the H-PAHs investigated, 9-chlorophenanthrene (9-ClPhe) showed the greatest detection rate (100%) and highest content (1.15 μg/kg), indicating that H-PAHs widely exist in aquatic products. Thus, further assessment of the dietary exposure risk of these compounds is necessary. The developed method simplifies the pretreatment step, and has the advantages of simplicity, rapid analysis, high recoveries, and good stability. It is suitable for the qualitative and quantitative analysis of H-PAHs in actual aquatic product samples and provides reliable technical support for the residue status and risk assessment of H-PAHs in aquatic products.

Bioaccumulation and trophic transfer of antibiotics in the aquatic and terrestrial food webs of the Yellow River Delta

Antibiotic pollution caused by aquaculture industries is a common problem in the wetland of the Yellow River Delta (YRD). Aquatic and terrestrial food webs coexist and interact in wetlands. However, there are few comparative studies on antibiotics in these two food webs. This study investigated the occurrence, bioaccumulation, and trophic transfer of 19 antibiotics in the aquatic and terrestrial food webs of the YRD, and discussed the effects of physicochemical parameters in different food webs. The total concentrations of antibiotics in aquatic organisms and terrestrial organisms ranged from 11.61 to 63.08 ng/g dry weight (dw) and 4.21–9.11 ng/g dw, respectively. BAF (bioaccumulation factor), BSAFa (biota sediment accumulation factor), and BSAFt (biota soil accumulation factor) were used to explore the bioaccumulation capacity of antibiotics. The calculation results of these three factors showed that fluoroquinolones (FQs) had the highest bioaccumulation capacity. As for the trophic transfer, the total concentrations of antibiotics were biodiluted in the aquatic food web while biomagnified in the terrestrial food web. Physicochemical parameters of the antibiotics showed that log Kow (octanol-water partition coefficient)/log Dow (pH-dependent distribution coefficient) and log Koa (octanol-air partition coefficient) were good predictors for antibiotic bioaccumulation in the aquatic and terrestrial organisms of the YRD, respectively. In addition, the increasing log Dow and log Koa led to a rise of TMF (trophic magnification factor) in the aquatic food web while a decrease of TMF in the terrestrial food web. Overall, these results provide insights into the mechanisms on bioaccumulation and trophic transfer of antibiotics in different food webs.

Potentially toxic element accumulation in two Equisetum species spontaneously grown in the flotation tailings

Decades of mining activity have resulted in the accumulation of significant amounts of tailings that are deposited over the natural vegetation, forming deposits tens of meters thick. The tailings are poor in organic matter and macronutrients and contain a high concentration of potentially toxic elements (PTE). Their surface remains unvegetated for long periods of time and is susceptible to fluvial and wind erosion. Equisetum arvense and E. telmateia appear to be the first colonizers in the tailings of the Pb?Cu?Zn mine in Serbia. Each plant was sampled along with its associated substrate. Pseudototal and available metals in the substrate, as well as total As, Cd, Cu, Fe, Mn, Ni, Pb and Zn concentrations in the plant parts were determined by atomic absorption spectrophotometry. The findings show that both species have high bioaccumulation capacity and tolerance to otherwise toxic concentrations due to efficient accumulation, immobilization and detoxification of these elements in their underground parts. It is expected that the long-term presence of metal-tolerant horsetail species would increase the organic matter content of flotation residues, thus gradually improving their physical, chemical and biological properties. This, in turn, would promote the natural succession of other metaltolerant plant species and soil microorganisms.

Perfluoroalkyl acids in representative edible aquatic species from the lower Yangtze River: Occurrence, distribution, sources, and health risk.

Perfluoroalkyl acid (PFAA) exposure poses a potential hazard to wildlife and humans. Food consumption is one of the main routes of PFAA exposure for the general population, with aquatic organisms being the major contributors. To evaluate the risk of coastal residents' intake of wild aquatic organisms, 14 PFAAs were detected in crucian carp and oriental river prawn from 18 sampling sites from the lower reaches of Yangtze River. The total PFAA (∑PFAA) concentrations ranged from 5.9 to 51.3ng/g wet weight (ww) in the muscle of crucian carp and river prawn, suggesting the potential risk to human and wildlife. Perfluorooctanesulfonate (PFOS), perfluorooctanoic acid (PFOA) and long-chain PFAAs (C≥10) were the main pollutants in the tissues of crucian carp and river prawn, which are known for their higher bioaccumulation capacity. The ∑PFAA concentration in all the samples showed an increasing trend from upstream to downstream and was higher in the south bank, owing to population density, prevailing winds, background pollution and industrial emission. Principal component analysis-multiple linear regression and Pearson correlation analysis showed that WWTP effluent, industrial pollution and surface runoff ware the main sources of PFAAs in the aquatic organisms and industrial pollution highest contributor, suggesting better regulation is needed to manage them. The assessment of risk to human health and wild life suggested a low risk for most residents of cities along the Yangtze River except for resident of Nantong, where frequent consumption of wild aquatic organisms may cause potential risk to human health, especially for traditional eaters and middle-aged people.

Spatiotemporal evaluation of organochlorine pesticide residues in bottom sediments of the Rio de Ondas hydrographic basin, western Bahia, Brazil.

The Rio de Ondas Hydrographic Basin (ROHB), Bahia state, Brazil, is located in a region with abundant water resources and is highly impacted by intense agricultural activity. In such a scenario, the use of organochlorine pesticides can represent a potential risk to the aquatic environments, due to their persistence, high bioaccumulation capacity, and high toxicity. Thus, organochlorine pesticide residues in bottom sediment samples from rivers on eighteen sites distributed along the ROHB in the dry and rainy periods were analyzed by gas chromatography coupled with mass spectrometry. The validated method showed no matrix effect, recoveries ranging from 82% (β-HCB) to 118% (DDD), limits of detection between 0.003ngg-1 (α-HCH) and 0.011ngg-1 (DDT), limits of quantification of 0.010ngg-1 (α-HCH) to 0.036ngg-1 (DDT), repeatability with the highest relative standard deviation of 0.97% (α-hexachlorocyclohexane at 2.000ngg-1), and inter-day precision ranging from 10% (aldrin at 0.050ngg-1 and 0.600ngg-1 and α-endosulfan at 0.600ngg-1) to 25% (β-endosulfan at 0.050ngg-1). Although most compounds were banned since 1985, it was observed that their residues were widely distributed in the ROHB, with the total concentrations varying from 3.242ngg-1 (P02) to 12.052ngg-1 (P17) and from 0.313ngg-1 (P14) to 30.861ngg-1 (P13) in the dry and rainy periods, respectively, which may be related to historical contamination and/or prohibited use. Moreover, the spatiotemporal variation showed the highest concentrations of organochlorine pesticide residues in the rainy season, coinciding with the planting period.

Impacts of copper on photosynthetic pigments and anatomy of Alcantarea imperialis (Bromeliaceae) under in vitro conditions

Description of the subject. Knowledge of morphophysiological status of plants and their responses to excess metals, such as copper (Cu), allows determining their potential use as bio-indicators. In vitro techniques are promising in studies that involve physiology and anatomy because they can isolate the effects of trace elements on morphophysiological features from other possible stress factors. Objectives. The aim was to verify the morphophysiological changes and adjustments of Alcantarea imperialis induced by excess Cu under in vitro conditions. Method. Alcantarea imperialis plants were transferred to in vitro culture media containing a concentration gradient of Cu (0, 25, 50, 100, or 200 μM). After 90 days, the contents of photosynthetic pigments and Cu were analyzed along with growth and anatomical features. Results. Plants cultured with Cu concentrations higher than 50 µM Cu had clear signs of toxicity, such as chlorosis. Plants exposed to 200 µM Cu showed a severe level of toxicity and were dead after 90 days. A drastic reduction of all photosynthetic pigments, as well as their ratios, was verified with exposure to 100 µM Cu. Plants exposed to that copper level presented the smallest stomata area, the lowest xylem number, as well as the thinnest vessel elements. The Cu content in the plants increased linearly as a function of Cu concentrations in the medium. Alcantarea imperialis plants can bioaccumulate high amounts of Cu. Conclusions. Alcantarea imperialis plants have good potential for bio-indication in urban areas due to their high Cu bioaccumulation capacity and clear morphophysiological changes. However, they have a low tolerance to very high Cu levels.

Impacts of copper on photosynthetic pigments and anatomy of Alcantarea imperialis (Bromeliaceae) under in vitro conditions

Description of the subject. Knowledge of morphophysiological status of plants and their responses to excess metals, such as copper (Cu), allows determining their potential use as bio-indicators. In vitro techniques are promising in studies that involve physiology and anatomy because they can isolate the effects of trace elements on morphophysiological features from other possible stress factors. Objectives. The aim was to verify the morphophysiological changes and adjustments of Alcantarea imperialis induced by excess Cu under in vitro conditions. Method. Alcantarea imperialis plants were transferred to in vitro culture media containing a concentration gradient of Cu (0, 25, 50, 100, or 200 μM). After 90 days, the contents of photosynthetic pigments and Cu were analyzed along with growth and anatomical features. Results. Plants cultured with Cu concentrations higher than 50 µM Cu had clear signs of toxicity, such as chlorosis. Plants exposed to 200 µM Cu showed a severe level of toxicity and were dead after 90 days. A drastic reduction of all photosynthetic pigments, as well as their ratios, was verified with exposure to 100 µM Cu. Plants exposed to that copper level presented the smallest stomata area, the lowest xylem number, as well as the thinnest vessel elements. The Cu content in the plants increased linearly as a function of Cu concentrations in the medium. Alcantarea imperialis plants can bioaccumulate high amounts of Cu. Conclusions. Alcantarea imperialis plants have good potential for bio-indication in urban areas due to their high Cu bioaccumulation capacity and clear morphophysiological changes. However, they have a low tolerance to very high Cu levels.

Bioremediation Capacity of Edaphic Cyanobacteria Nostoc linckia for Chromium in Association with Other Heavy-Metals-Contaminated Soils

Anthropogenic activity is the main factor contributing to soil pollution with various toxic metals, including Cr(VI), which dictates the need for decontamination. Often, the traditionally used remediation methods (soil removal, stabilization/solidification, physicochemical extraction, and soil washing) are not sufficiently efficient. Among gentle soil remediation, options can be considered. The aim of this study is to assess the ability of Nostoc linckia to remediate soils contaminated with Cr(VI) in association with other metals. Metal uptake by biomass was assessed using neutron activation analysis, while the components of Nostoc biomass were determined using specific methods. The capacity to accumulate chromium from the contaminated environment (Cr in association with Fe, Ni, Cu, and Zn) by the Nostoc linckia is kept at a high level for three generations of cyanobacterium, and the capacity to accumulate Fe, Ni, Cu, and Zn is growing over the cultivation cycles. The process of accumulation of heavy metals is associated with significant changes in the biochemical composition of Nostoc biomass. Due to the high bioaccumulation capacity and the specific growth mode with the formation of crusts on the soil surface, the edaphic cyanobacteria Nostoc linckia is an important candidate for the bioremediation of soil contaminated with chromium in association with other metals.

Trace element bioaccumulation in hypersaline ecosystems and implications of a global invasion

Hypersaline ecosystems are under increasing threat due to anthropogenic pressures such as environmental pollution and biological invasions. Here we address the ecotoxicological implications of the Artemia franciscana (Crustacea) invasion in saltpans of southern Spain. This North American species is causing the extinction of native Artemia populations in many parts of the globe. The bioaccumulation of trace elements (As, Cd, Cu, Co, Cr, Mn, Ni, Pb and Zn) in native populations (A. parthenogenetica) from Cabo de Gata and Odiel saltpans and invasive Artemia from Cádiz saltpan was studied at different salinities. Furthermore, in Odiel, the most polluted study site, we also analysed the bioaccumulation of trace elements by Chironomus salinarius larvae (Diptera) and Ochthebius notabilis adults (Coleoptera). High levels of trace elements were detected in the studied saltpans, many of them exceeding the recommended threshold guidelines for aquatic life. Bioaccumulation of trace elements by Artemia was lowest at the highest salinity. The invasive A. franciscana showed higher potential to bioaccumulate trace elements than its native counterpart (in particular for As, Cd, Ni and Cr). In Odiel, O. notabilis stood out as showing the highest potential to bioaccumulate As and Cu. Results showed that the shift from a native to an alien Artemia species with a higher bioaccumulation capacity may increase the transfer of trace elements in hypersaline food webs, especially for waterbirds that depend on Artemia as food. Thus, our study identifies an indirect impact of the Artemia franciscana invasion that had not previously been recognised.

SOIL POLLUTION WITH HEAVY METALS AND BIOREMEDIATION METHODS

The soil is a living and dynamic ecosystem permanently subject to anthropogenic pollution. Heavy metal pollution is a major factor of microbiota imbalances, and thus of severe soil degradation. The microbiota is represented by a wide range of microbial species that maintain and improve soil fertility by performing biogeochemical cycles in nature. Heavy metals are found naturally in the soil and play a key role in supporting microbial processes, but excess waste stored and neutralized improperly can be harmful, due to bioaccumulation along the trophic chain. Among the heavy metals commonly found in the soil are: lead (Pb), chromium (Cr), zinc (Zn), cadmium (Cd), copper (Cu), mercury (Hg), and nickel (Ni). The mobility of heavy metals in the environment, in general, and in the soil, in particular, is reduced, and therefore their contact with microorganisms is long and influences the structure of the microbial community. Existing studies emphasize the high bioaccumulation capacity of cadmium but also increased mobility affecting an entire trophic chain, and lead exerts an inhibitory effect on telluric microorganisms, even at very low concentrations. The overall activity of the soil, denitrifiers, and enzymes, is deeply affected by the presence of heavy metals. Their effect depends on the concentration and pH of the soil. Pedoclimatic factors can also contribute to these changes. Even in this situation, microorganisms can contribute to bioremediation and rendering the soil in the agricultural circuit. Among the bacterial genera that have developed mechanisms of resistance to certain heavy metals are Bacillus, Arthrobacter, Corynebacterium, Pseudomonas, Alcaligenes

Effect of zinc-containing systems on Spirulina platensis bioaccumulation capacity and biochemical composition.

Cyanobacteria Spirulina platensis due to its high biosorption and bioaccumulation capacity toward metal ions can be considered as an excellent candidate for environmental bioremediation. The effect of Zn and in different combinations on the accumulation capacity of Spirulina platensis biomass and its biochemical composition was investigated. Four Zn-containing systems with a different combination of metal ions (Zn; Zn/Cu/Sr; Zn/Cu/Ni; Zn/Cu/Sr/Ba) and different metal concentrations were modeled. Studied systems were introduced in the cultivation medium on the fifth day of biomass grow and experiments were performed in three variants, which differed by metal ions concentrations. Metal uptake by biomass was traced using neutron activation analysis. Spirulina platensis showed a high accumulation capacity for all metal ions present in the analyzed system. Because the metals were added at the beginning of the stationary growth phase, the contact with the biomass was only 24 h, even at the highest metal concentration in the systems, the accumulation of Spirulina platensis biomass was reduced by no more than 11.2%. Spirulina platensis biomass grown in a mono-metallic system expressed two biochemical indicators of stress: decrease of phycobiliprotein content and increase of malondialdehyde content. In biomass grown in the presence of Zn-containing multi-metallic systems, three indicators of stress were expressed: decrease of protein content, reduction of phycobiliprotein content, and increase of malondialdehyde content. Spirulina platensis biomass can be considered as an effective accumulator for the treatment of zinc-containing industrial effluents.

Iron Bioaccumulation in Lentinus crinitus Mycelia Cultivated in Agroindustrial Byproducts

Iron deficiency anemia is a challenge to global public health, and the development of iron-enriched foods are an opportunity to reduce this problem. Lentinus crinitus is a basidiomycete with high metal bioaccumulation capacity that is consumed by Amazonian Indians. This study aimed to evaluate iron bioaccumulation in the mycelial biomass of L. crinitus cultivated in agroindustrial byproducts. First, the fungus grew in a liquid medium with iron addition from 0.116 (control) to 100 mg L−1. The addition of 90 mg L−1 iron to the culture medium resulted in 15.07 ± 1.44 dg kg−1 of iron mycelial bioaccumulation, a 9000-fold increase compared with the control. Then, the fungus grew in agroindustrial byproducts sugarcane (SCM) or soybean (SBM) molasses added with 90 mg L−1 iron and 0.9 mg L−1 manganese, a new element in the assay. The iron concentrations in the mycelial biomass cultivated in SCM or SBM were 20.78 ± 2.28 or 34.71 ± 4.31 dg kg−1, respectively, at 21 cultivation days. The cultivation time and the presence of iron and manganese in the culture media were important variables for iron bioaccumulation in the mycelial biomass. Our study evidenced that agroindustrial byproducts, mainly SCM, can be used to successfully produce mycelial biomass enriched with iron - as an alternative functional food - to add value to the food production chain. Also, the iron-enriched biomass can be an alternative for non-living animal protein supply.

Bioaccumulation of Potentially Toxic Elements by the Needles of Eleven Pine Species in Low Polluted Area

This study presents the results of comparative analyses carried out in the Arboretum Mlyňany, located in an uncontaminated area of south-western Slovakia. Bioaccumulation intensity of Cr, Cu, Mn, Ni, and Zn in the needles of eleven pine species was evaluated. Spectroscopic techniques along with standard protocols were applied to analyze elements content in 1- and 2-year-old needles and soil samples collected from 30 locations. The results were evaluated using Cluster Analysis and Kruskal-Wallis test. In examined stands, soil Cr, Cu, Mn, Ni, and Zn contents ranged from 14.4 to 32.6, 6.3 to 46.5, 619.4 to 2228.4, 13.2 to 37.4, and 35.2 to 62.5 mg kg−1, respectively, revealing low vertical mobility. Elemental concentrations were typical for fine-textured, uncontaminated soils of Central and Eastern Europe. Total Cr, Cu, Mn, Ni, and Zn in pine needles ranged from 10.0 to 23.5, 2.6 to 7.6, 19.6 to 1804.2, 24.1 to 103.1, and 8.1 to 55.1 mg kg−1, respectively, revealing slight differences between accumulation in 1- and 2-year-old needles. Pinus rigida Mill and Pinus sylvestris L. demonstrated the highest bioaccumulation capacity. The results presented in our study point to a specific bioaccumulation capacity of 11 pine species under low soil pollution levels.

Biomonitoring of Effects and Accumulations of Heavy Metals Insults Using Some Helminth Parasites of Fish as Bio-Indicators in an Afrotropical Stream

Studies on biomonitoring the aquatic environment using host-parasite dynamics as bio-indicators of effects and accumulators of heavy metals insults are still scarce, particularly in the tropics. In our study, we aimed at elucidating the possible use of helminth parasites of fish in monitoring and controlling heavy metal pollution. Samples were collected from an anthropogenically polluted river in north central region of Nigeria over a period of 24 months (September 2014 and October 2016). Water, fish muscle, and fish parasites samples of three dominant fish species were collected, processed, and analyzed for copper, lead, manganese, iron, zinc, and chromium. The metal concentrations in parasites of: Clarias garienpinus was in the order of Fe > Zn > Cr > Mn > Pb > Cu; Tilapia zillii was in the order of Fe > Zn > Mn > Cu > Cr > Pb; and that of Raimas nigeriensis was in the order of Fe > Zn > Cr > Mn > Cu > Pb. The CCA ordination revealed strong relationships between fish parasites and heavy metals pollution. Generally, Fe, Zn, Mn, Cu, Cr, and Pb concentrations in the parasites of all fish species were clearly higher than those in the muscles of the fish hosts. Pb was not detected in the fish muscles of Raimas nigeriensis but was detected in the parasites of the fish, thus indicating high bioaccumulation capacity of the parasites. The close linkage between Eustrongylides sp. and zinc could mean that Eustrongylides sp. was an ideal surrogate for zinc pollution. This study revealed that intestinal helminthic parasites can be ideal surrogates for both effects and accumulation bioindication of heavy metal pollution.

Morphophysiological responses, bioaccumulation and tolerance of Alternanthera tenella Colla (Amaranthaceae) to excess copper under in vitro conditions

Copper (Cu) is an essential metal and both its deficiency and excess has negative effects on the growth and physiology of plants. Some plant species can tolerate high Cu concentrations due to their anatomical and physiological strategies. These plants can avoid absorption or accumulate this element in their biomass. Thus, the aim was to analyze the anatomical and physiological changes of Alternanthera tenella in response to excess Cu under in vitro conditions. A. tenella plants, previously established in vitro, were transferred to culture media containing 0, 25, 50, 100 or 200 µM Cu. At 30 days of culture, the stem and leaf anatomy, contents of photosynthetic pigments mineral nutrients, chlorophyll fluorescence, and, growth were analyzed. The excess Cu induced lower biomass accumulation. Plants also presented a decline in cell sizes of stem and leaf tissues under high Cu concentrations. Greater formation of druse crystals and lower number of active reaction centers (RC/CSM) were observed with 200 μM Cu. The Cu treatments modulated the contents of mineral nutrients and photosynthetic pigments of the plants. Plants cultured in media with Cu absence or excess (200 μM Cu) presented partial inhibition of electron transport and photochemical activity of photosystem II. Even though A. tenella plants showed clear signs of stress under Cu excess, they also have a strong capacity for Cu bioaccumulation and tolerance. A. tenella plants can be used for phytoremediation or bioindication due to their tolerance and high Cu bioaccumulation capacity. Copper can modulate the morphophysiology of A. tenella under in vitro conditions. A. tenella can be used for phytoremediation or bioindication due to its tolerance and high copper bioaccumulation capacity.

Bioconcentration of Essential and Nonessential Elements in Black Sea Turbot (Psetta Maxima Maeotica Linnaeus, 1758) in Relation to Fish Gender

This study investigates the influence of gender in the bioconcentration of essential and nonessential elements in different parts of Black Sea turbot (Psetta maxima maeotica) body, from an area considered under high anthropogenic pressure (the Constanta City Black Sea Coastal Area in Romania). A number of 13 elements (Ca, Mg, Na, K, Fe, Zn, Mn, Cu, Ni, Cr, As, Pb and Cd) were measured in various sample types: muscle, stomach, stomach content, intestine, intestine content, gonads, liver, spleen, gills and caudal fin. Turbot adults (4–5 years old) were separated, according to their gender, into two groups (20 males, 20 females, respectively), and a high total number of samples (1200 from both groups) were prepared and analyzed, in triplicate, with Flame Atomic Absorption Spectrometry and High-Resolution Continuum Source Atomic Absorption Spectrometry with Graphite Furnace techniques. The results were statistically analyzed in order to emphasize the bioconcentration of the determined elements in different tissues of wild turbot males vs. females, and also to contribute to an upgraded characterization of the Romanian Black Sea Coast, around Constanta City, in terms of heavy metals pollution. The essential elements Mg and Zn have different roles in the gonads of males and females, as they were the only elements with completely different patterns between the analyzed groups of specimens. The concentrations of studied elements in muscle were not similar with the data provided by literature, suggesting that chemistry of the habitat and food plays a major role in the availability of the metals in the body of analyzed fish species. The gender influenced the bioaccumulation process of all analyzed elements in most tissues since turbot male specimens accumulated higher concentration of metals compared to females. The highest bioaccumulation capacity in terms of Ca, Mg, Na, Ni, As, Zn and Cd was registered in caudal fin, liver and intestine tissues. Also, other elements such as K, Fe, Cu and Mn had the highest bioaccumulation in their muscle, spleen, liver and gills tissues. The concentrations of toxic metals in Black Sea turbot from this study were lower in the muscle samples compared with the studies conducted in Turkey, suggesting that the anthropogenic activity in the studied area did not pose a major impact upon the habitat contamination.