Metal Bioconcentration Factors Research Articles

Effects of Organic Manure on Wheat Yield and Accumulation of Heavy Metals in a Soil—Wheat System

The application of organic manure is an effective way to develop sustainable agriculture. However, the application of organic manure may be associated with a potential risk of heavy metal pollution for soil and crops. In this study, the effects of organic cow manure (T1) (as base fertilizer), organic pig manure (T2) (as base fertilizer) and chemical fertilizer (T3) on winter wheat grain yields, grain quality, heavy metal concentrations and heavy metal bioconcentration factors (BCFs) in a soil–wheat system were studied from November 2021 to June 2023. The results showed that the winter wheat grain yields in the T1 and T2 treatments were lower than those in the T3 treatment by 2.57–38.0% and 10.5–25%, respectively. There were no significant differences in quality indexes of winter wheat grain among different fertilizer treatments. The concentrations of heavy metals in topsoil and winter wheat were 0.12–76.11 μg/g and 0.01–43.25 μg/g, respectively. The BCFs of heavy mental in the soil–wheat grain system was 0–2.92. In general, there were no significant differences in heavy metals’ concentrations in topsoil and wheat grain among different fertilizer treatments. In summary, compared with chemical fertilizer, the short-term application of organic manures had no significant effect on heavy metals concentrations in topsoil and wheat.

Comparison among native floating aquatic macrophytes for bioconcentration of heavy metals

This work was aimed to show the development of a comparative study of the capability of bioindicators to reveal the presence of heavy metals among species of floating aquatic macrophytes such as Spirodela sp (giant duckweed), Pistia stratiotes (water lettuce), Salvinia sp used as a parameter for bioconcentration factors plant / sediment. We performed a simple sampling at six sites in the region of Pelotas, southern Brazil, in which it was collected sediments and plants. The plants experienced the nitric perchloric acid digestion method, while the sediment suffered pseudo total acid digestion method. The determination of Cr, Cu, Pb and Zn in the extracts was conducted by atomic absorption spectrophotometry in flame. In general, the floating aquatic macrophytes studied showed better bioconcentration factor for metals from the sediment in the following order: Cu>Zn>Pb>Cr. For copper, the figures obtained with Pistia stratiots ranged from 5.7 to 82.8. The BCF for Zn ranged from 3.0 to 11.6 and Salvinia sp. For the Pb bioconcentration factor, it ranged from 5.4 to 0.6 in Spirodela sp. The in situ study showed that all species had high bioaccumulation potential, especially Pistia stratiotes that was employed to remove copper.

The concentration of Pb, Cd, and Sn in vegetables from ex-tin mining land in Bangka, Indonesia

Utilization of ex-tin mining land as agricultural land is thought to have the potential to contribute heavy metals in agricultural products. The research objective was to obtain data on the metal content of Pb, Cd, and Sn in various vegetable crops such as spinach, cucumber, tomato, cayenne pepper, bitter guard, eggplant, pumpkin, and pepper. In addition to obtaining data on bioconcentration factors (BCFs) of metals in various vegetables. Vegetables were obtained from ex-mining vegetable fields in Jelitik Village, Gunung Pelawan, and Rebo Village, and metal measurements used Analytical Flame Atomic Absorption Spectrophotometry (F-AAS) Jena ContrAA 300. The results showed that the Sn metal in all vegetables analyzed ranged from 4.71 -10.86 mg/kg, Pb ranged from 0 – 5.0 mg/kg, and Cd metal was not found in all the vegetables and soil samples analyzed. The highest of Sn was found in spinach, and Pb in pepper. Generally, the Pb, Cd, and Sn content in vegetables still meets the Indonesian National Standard (SNI) No. 7387:2009, because not exceed the recommended quality standards. Soil from the three villages of ex-tin mining is not categorized as polluted with Pb, Cd, and Sn metals because it does not exceed the target values recommended by WHO. The TFs (Transfer Factors) value of metals in all types of vegetables analyzed was < 1, meaning that the ex-tin mining lands in Jelilik Village, Gunung Pelawan, and Rebo Village, Bangka are still relatively safe for growing vegetables because they do not contribute to the pollution of Pb, Cd, Sn.

Effect of Humic Acid Functionalized Bentonite on Heavy Metal Uptake by Spinach (Spinacia oleracea cv. All Green) Grown on Metal Contaminated Soil

A pot culture study was conducted to investigate the impact of applying humic acid functionalized bentonite (HA-B) on the uptake of heavy metals by spinach. When the soil was amended with 7.5 g kg-1 of humic acid intercalated bentonite, there was a significant improvement in plant growth. Specifically, plant growth increased by 180.7%, 212%, and 231% during the first, second, and third cuttings, respectively. Additionally, the concentration of metals in the spinach decreased substantially, with reductions of 62.8, 69.7, and 77.7% for Cd and 34.7%, 45.2%, and 64.7% for Ni during the first, second, and third cuttings, respectively, when 7.5 g kg-1 of humic acid functionalized bentonite was applied. Furthermore, the addition of humic acid intercalated bentonite at a rate of 7.5 g kg-1 to the soil significantly lowered the bioconcentration factor (BCF) of metals. The BCF decreased by 36.3%, 40%, and 55.2% for Cd and 15.2%, 13%, and 34.7% for Ni during the first, second, and third cuttings, respectively, indicating a reduced uptake of these metals by the plants. Moreover, the non-cancer health risk through hazard quotient (HQ) computation showed that the risk was significantly reduced due to consumption of spinach by the application of 7.5 g kg-1 of humic acid intercalated bentonite.

The carrying capacity of estuarine mangroves in maintaining the coastal urban environmental health of Southeast Sulawesi, Indonesia

This study aims to elucidate the carrying capacity of estuarine mangroves in Southeast Sulawesi, to maintain environmental health of its coastal cities. The concentrations of mercury (Hg), Copper (Cu), Manganese (Mn), Lead (Pb), Zinc (Zn), and Nickel (Ni) were analyzed in sediments and mangrove tissues samples from Kendari bay and Tinanggea estuaries. This was followed by the determination of translocation and bioaccumulation factors, as well as the total accumulation of heavy metals on a landscape level. The results showed that the sediment in Kendari Bay had higher heavy metal concentrations than in Tinanggea, indicating the anthropogenic impact of the highly populated city of Kendari. Moreover, the roots and stems of mangroves had higher heavy metal concentrations than the leaves. Overall, the Bioconcentration Factors (BCF) of Hg, Cu, Mn, Pb and Zn metals were >1, indicating that estuarine mangroves have a higher phytoremediation capacity for heavy metals. Estuarine mangrove biomass also enables the high accumulation of heavy metals in both Kendari bay and Tinanggea, signifying the greater phytoremediation potential of urban estuarine mangroves. Based on these findings, the study supports the conservation and management of mangroves in urban estuaries to maintain the environmental health of coastal cities.

Heavy metal exposure risk associated with ingestion of Oreochromis niloticus and Coptodon kottae harvested from a lacustrine ecosystem

Lacustrine ecosystems have not been widely assessed for heavy metal contamination and associated health risks; yet, they could be accumulating these contaminants to the detriment of aquatic organisms and communities relying on them for various aspects. The water quality index (WQI) and concentrations of heavy metals including As, Cd, Co, Cu, Cr, Fe, Mn, Ni, Pb, and Zn in water, sediment, Oreochromis niloticus, and in the endemic and endangered Coptodon kottae in Lake Barombi Kotto in Cameroon were determined to evaluate fish heavy metal bioaccumulation, and heavy metal exposure risk posed to communities consuming these fish species. The WQI of the lake was found to be excellent with heavy metal concentrations that were lower than what was obtained in the sediments and fish samples. Mean heavy metal concentrations in sediment ranged from 0.86 ± 0.03 mg/kg for Cd to 560.1 ± 11.15 mg/kg for Fe. In both fish species, Fe, Mn, and Cu had the highest concentrations. Though the heavy metal concentrations in the lake water were low, heavy metal bioconcentration factors for both fish species were very high ranging from 1.6 for Fe to 1568 for Mn. The concentration patterns of heavy metals in the organs of both fish species followed the order bones > gut > muscle. Consumption of these two fish species contributes less than 1.0% of the permissible tolerable daily intake (PTDI) and provisional tolerable weekly intake (PTWI) of these metals with lead (Pb) having the potential to exceed permissible exposure levels when high amounts of these fish are consumed by adults.

Ecological risk assessment and phytomanagement of trace metals in the sediments of mangroves associated with the Ramsar sites of Kerala, southern India.

The study investigated trace metal accumulation in the sediments of three major mangrove ecosystems associated with the Ramsar sites of Kerala state, the ecological risks they pose, and the absorption, accumulation, and translocation of metals in five dominant mangrove species, as these systems are heavily impacted by anthropogenic interventions. The trace metal concentrations (mg kg-1) in the sediment of different mangrove habitats of Kerala ranged from 20 to 295 for Cu, 65 to 350 for Zn, 72 to 151 for Pb, 11 to 210 for Ni, 42 to 228 for Mn, 0 to 6 for Cd,124 to 565 for Cr, and 0 to 2.9 for Ag. An overall enrichment of metals was recorded in sediment, exceeding the prescribed effects range median (ERM) of consensus-based sediment quality guidelines (SQGs) for Cu and Cr concentrations at Munroe Island and Ni at Vypin, indicating a detrimental risk to biota in the sediments. Principal component analysis and a higher geoaccumulation index indicated the contribution of trace metals from industries, agricultural runoff, and urban waste disposal. The ecological risk index suggested that cadmium poses a very high risk to the mangrove ecosystem at Vypin. Furthermore, the bioconcentration factor for various trace metals in Avicennia marina and Lumnitzera racemosa in Ayiramthengu was > 2, suggesting that these species can accumulate trace metals, particularly Cr, Cd, and Pb. Further, our findings suggest that A. marina may be considered as an efficient metal trap for Cd in aerial parts, as indicated by the significant translocation factor (> 1) combined with the bioconcentration factor. Therefore, the study revealed that Munroe island and Vypin had a considerable level of contamination for toxic metals and Avicennia marina could be a promising candidate species for the phytoremediation of these trace metals in the coastal settings of Kerala state.

Coriander (Coriandrum sativum L.) in Combination with Organic Amendments and Arbuscular Mycorrhizal Inoculation: An Efficient Option for the Phytomanagement of Trace Elements-Polluted Soils.

The cultivation of coriander (Coriandrum sativum L.) destined for essential oils production was recently presented as an innovative and economically viable alternative for the phytomanagement of trace elements (TE)-polluted soils. However, Cd accumulation in shoots has proven to be an obstacle in the valorization of the distillation residues and the development of these phytotechnologies. The present study aimed to evaluate the effect of arbuscular mycorrhizal fungus (Funneliformis mosseae) inoculation and organic amendment application on the soil TE bioavailability and plant uptake, as well as on the soil quality and health improvement. The application of compost and sewage sludge improved the growth of coriander and Cd and Zn immobilization in soil, resulting in reduced Cd plant uptake. A synergistic effect of arbuscular mycorrhizal fungi (AMF) inoculation and organic amendments was observed in the decrease in the extractable soil Cd and Zn concentrations, but not in the Cd plant uptake. Despite a significant decrease in Cd accumulation in shoots, coriander retained its accumulative phenotype, with a metal bioconcentration factor close to 1. Furthermore, both the vegetation and the organic amendments improved the soil quality and health by increasing its microbial biomass, as estimated by phospholipid fatty acids, soil enzyme activities (dehydrogenase, phosphatase, β-glucosidase, and cellubiosidase), and the bacterial metabolic function and diversity. The findings demonstrate the potential of C. sativum, particularly in combination with organic amendments and AMF inoculation, for the phytomanagement of TE-polluted soils and soil quality and health improvement.

New insights into trace metal speciation and interaction with phytoplankton in estuarine coastal waters

In coastal productive zones, phytoplankton activity may influence trace metal speciation and partitioning at short temporal scale. We coupled hourly in situ voltammetry quantification of the lead (Pb), cadmium (Cd), and copper (Cu) potentially bioavailable fractions, using an innovative submersible sensing probe (the TracMetal), to surface water sampling for the quantification of the targeted trace metals in the dissolved <0.2 μm and <0.02 μm fractions, suspended particles, and phytoplankton nets in the Gironde Estuary mouth. The in situ TracMetal monitoring reflected real-time dynamic Cd and Cu regeneration related to algal cells under post-bloom conditions as well as Pb remobilization due to photoreduction of colloids. The potentially bioavailable fraction consisted in 30, 30–50 and <10 % of the total dissolved fraction for Pb, Cd, and Cu, respectively, representing crucial ecotoxicological information. Metal bioconcentration factors using the dynamic fraction concentrations showed levels up to 107 for Cu in phytoplankton.

Effect of Mass Ratio on Phytoremediation of Nickel Contaminated Water

Water pollution is one of the global challenges that the society must address in the 21st century aiming to improve the water quality, reduce human pollutants and ecosystem health impacts. In phytotoxicity test, the plant of Iresine herbstii was exposed to remove nickel from simulated wastewater using two different ratios (mass of plant to the mass of nickel) (,Rp/Ni) for 21 days with sub-surface batch system. During the exposure period, the removal of Ni concentrations (2, 5 and 10 mg/L) for two mass ratio (2,800 and 34,000) were (83.6%, 77.2%, 78.0%) and (86.8%, 97% and 95.6%), respectively. final result of the rate was found that the highest removal occurred, 97%, at a mass ratio of 34,000 and a nickel concentration of 5 mg/L. Metal accumulation mechanism of plants were examined using bioconcentration factor (BCF) and translocation factor (TF) of metals which indicated that I. herbstii is suitable for phytostabilization of Ni (BCF&gt;1 and TF&lt;1). Therefore, the ability of I. herbstii to treat wastewater contaminated with nickel that I. herbstii is considered a potential plant to remove Ni from contaminated water.

Bioaccumulation of metals by algae from acid mine drainage: a case study of Frongoch Mine (UK)

In Frongoch Mine (UK), it is unclear the distribution of metals on indigenous algae and whether these species of algae can accumulate metals. This study aimed to investigate the role of indigenous algae for metal removal from acid mine drainage and understand if metals can be adsorbed on the surface of algae or/and bioaccumulated in algae. A sequential extraction procedure was applied for algae samples collected from acid mine drainage (AMD) water to identify the forms in which metals are found in algae. Concentrations of Fe, Pb, Zn, Cu and Cd were evaluated in the algae and AMD samples were collected in June and October 2019. AMDs samples had a pH value ranging between 3.5 and 6.9 and high concentrations of Zn (351 mg/L) and Pb (4.22 mg/L) that exceeded the water quality standards (Water Framework Directive, 2015). Algae Ulothrix sp. and Oedogonium sp. were the two main species in the Frongoch AMDs. The concentrations of metals in algae ranged from 0.007 to 51 mg/g, and the bioconcentration factor of metals decreased in the following order: Fe > > Pb > > Cu > Cd > Zn. It was found that Zn, Cu and Cd were adsorbed onto the surface of and bioaccumulated in the algae, while Pb and Fe were mainly bioaccumulated in the algae. Indigenous algae can be considered as a biogeochemical barrier where metals are accumulating and can be used in bioremediation methods. Also, indigenous algae could be used as a bioindicator to assess water pollution at Frongoch Mine and other similar metal mines.

Black Sea Mussels Qualitative and Quantitative Chemical Analysis: Nutritional Benefits and Possible Risks through Consumption.

Mussels have a particular nutritional value, representing a highly valued food source and thus sought after worldwide. Their meat is a real culinary delicacy, rich in proteins, lipids, carbohydrates, trace elements, enzymes, and vitamins. The seasonal variation of mussels’ biochemical composition has been studied to determine the best harvesting period to capitalize on various biologically active fractions. In this work biochemical determinations have been performed on fresh flesh samples of Mytilus galloprovincialis specimens from the Black Sea coast to study seasonal variations in mussels’ biochemical compounds. An analysis of significant lipid classes and the fatty acid composition of lipid extracts obtained from mussel flesh has also been performed. Since mussels retain pollutants from the marine environment, in parallel, the concentration of heavy metals in the meat of mussels collected for the analysis of the chemical composition was investigated. The impact and risk of heavy metal poisoning due to food consumption of mussels contaminated due to pollution of the marine harvesting area was evaluated by the bio-concentration factor of metals and estimated daily intakes of heavy metals through mussel consumption.

Micro-pollutant Pb(II) mitigation and lipid induction in oleaginous microalgae Chlorella sorokiniana UUIND6

Green oleaginous microalgae are good candidates for the integration of heavy metal bioremediation with the generation of biofuels. To be effective, this requires a comprehensive understanding and optimization of the metal concentration that generates maximum growth along with a high yield of lipids from microalgae cells. This work follows the aforementioned strategy and involves the use of oleaginous microalgae Chlorella sorokiniana for lead mitigation and biodiesel production. The short-term effects (IC50 value at 96 h of culture) and the long-term effects (pigments and biomass) of the exposure of lead (Pb) to the growth and biochemical compositions (pigments, proteins, carbohydrates, and lipids) of microalgae have been also determined. Chlorella sorokiniana has a high half-maximal inhibitory concentration (IC50 value and higher metal bio-concentration factor (BCF) for Pb (II), which represents that this strain can be considered as a lead (Pb) hyperbioaccumulator. FTIR analysis revealed a reduction in proteins and carbohydrates under the influence of Pb while an increase in lipids has been recorded. The lipid profile based on 1H NMR and GC–MS has been followed for the quality analysis of the biodiesel produced that indicated altered lipid profiles under stress by Pb and elevated levels of SFA and MUFA.

Effect of macroelements application on the behavior of heavy metals, growth and production of jojoba plant irrigated with industrial wastewater

This research aims to study the growth and production of jojoba plant as abiofuel crop under fertilization with N, P & K and irrigation with industrial wastewater as a source of untraditional irrigation water. So, over two consecutive growing seasons on 6th year fruiting Jojoba shrubs grown on sandy soil at private orchards located in El-Assiuty Valley, Assiut Governorate, Egypt (27o12'18.2 N & 30o59'20.0E), a field experiment was laid out in a randomized complete block design with split plot technique where the main factor was the different nitrogen sources (i.e. urea U, ammonium sulphate AS, ammonium nitrate ANand calcium nitrate CA) at 240kgNha-1, while the sub main factor was allocated for five combinations of P and K fertilizer as follows [control; no application, P1; 75P2O5ha-1, K1; 60kgK2Oha-1, P1K1; 75P2O5 + 60kgK2Oha-1 and P2K2; 150P2O5 + 120kgK2Oha-1]. Results indicated that using 240kgNha-1 as ammonium sulphate with 150P2O5 + 120kgK2Oha-1 showed the highest significant increasing in most of the studied parameters such as nutrients availability, vegetative growth, and yield of jojoba plants. Bioconcentration factor (BCF) for heavy metals in leaves and seeds of jojoba shrub showed a trend in the following order; Cu > pb > Mn > Zn > Fe. More future researches are still required to study the side effects of using artificial wastewater on oil quality of jojoba seeds.

Translocation of Heavy Metals in Herbs under Urban Anthropogenic Pollution Conditions

This study aims to examine the translocation of heavy metals from urban soils to herbs in Tyumen (Russian Federation). The mobile and acid-soluble heavy metal fractions in soils, as well as the heavy metal contents in plants, were determined by atomic absorption spectrophotometry. The bioconcentration factor was estimated as the ratio of the amount of heavy metals in soils to that in plants. Heavy metal concentrations in urban soils were higher than those at the control site by 20% and by up to 10 times. The greatest heavy metal accumulation in both soils and plants was found at the battery manufacturing and metallurgical plants, exceeding the control levels of Pb and Fe by 2–17 times. The Cu, Fe and Mn contents in soil were positively correlated with those in plants. Heavy metal translocation by the plants was species-specific. The percentages of the mobile heavy metal fractions decreased in the following order: Mn > Zn > Cu > Fe. Heavy metal accumulation in Poa pratensis, Trifolium rubens, Vicia cracca, Matricaria chamomilla and Tussilago farfara in the urban sites compared to that at the control site decreased in the following order: Fe > Zn > Cu > Mn > Pb > Cd. Tussilago farfara exhibited the highest Fe, Mn and Zn accumulation, which exceeded the control levels by 17, 5 and 3.5 times, respectively. The heavy metal bioconcentration factors, indicators of translocation, decreased in the following order: Cu > Zn > Cd > Pb > Mn > Fe. The heavy metal translocation suggests the need to relocate industrial facilities to areas outside the city. Future monitoring of the study area is needed to ensure its long-term ecological safety. • The heavy metal concentration in urban soils was elevated indicating ecological risk • Iron was the most accumulated metal in all examined plant species • Heavy metal translocation in coltsfoot was higher than that in the four herb species

Nutrient and heavy metal composition in select biotic and abiotic components of Varthur wetlands, Bangalore, India

Lakes or wetlands in urban landscapes provide services such as groundwater recharge, provide fish, fodder and food to the dependent local population, mitigate floods, habitat for fauna, support recreation, etc. Unplanned rapid urbanization with globalization and industrialization has led to the sustained inflow of untreated wastewater from domestic and industrial sectors to water bodies leading to eutrophication and heavy metal contamination. This necessities treatment of sewage and industrial effluents, which needs to be technically feasible and economically viable. This communication investigates the distribution and accumulation of nutrients (carbon and nitrogen) and six heavy metals (cadmium, chromium, copper, nickel, lead and zinc) in the sediment and macrophyte samples of Varthur lake, Bangalore. Higher carbon and nitrogen values in sediment samples of the northwest and northeast shorelines were observed, whereas lower carbon and nitrogen values were observed in the samples of middle and outlets of the lake. Shoots of Colocasia esculenta and Alternanthera philoxeroides accumulated higher amount of carbon and nitrogen. Sediment samples of north shoreline and inlet portion of the Lake had high concentration of heavy metals in Alternanthera philoxeroides and Eichhornia crassipes accumulated heavy metals in higher extent among macrophyte species. Sediment samples had higher concentrations of copper (Cu) followed by zinc (Zn), chromium (Cr), lead (Pb), nickel (Ni) and cadmium (Cd). Compared to this, accumulation of heavy metals in macrophyte samples is in the order Cu > Zn > Cr > Pb > Ni > Cd. Assessment of bioconcentration factor and translocation factor of metals in macrophytes revealed the prospects of select macrophytes in phytoremediation for mitigating metal pollution through phytoextraction and phytostabilization.

Biota sediment accumulation and bioconcentration factors of trace metals in the snail Melanoides tuberculata form the agricultural drains of the Manzala Lagoon, Egypt.

The freshwater mollusk, Melanoides tuberculata, contains bioconcentration trace metals in its tissues from the surrounding area. M. tuberculata was used as a bioindicator for pollution with seven trace metals (Mn, Fe, Ni, Cu, Zn, Cd, and Pb) accumulated in snail soft tissues near Bahr El-Baqar and El-Serw agricultural drains of industrial activities in Port Said and Damietta, respectively. The biota sediment accumulation factors (BSAF) in this study reveals that all the soft tissues of the M. tuberculata snails were macro-concentrators with the exception of Ni; it was deconcentrated, and thus provides that the selective tissues as good biomonitors. The bioconcentration factor (BCF) showed the highest concentrations of Fe and Cu in the soft tissues of the M. tuberculata snail, which has the potential to be used as a biomonitoring agent for Fe and Cu contamination of the water.

Dynamics of Metal Pollution in Sediment and Macrophytes of Varthur Lake, Bangalore.

Eutrophication and metal contamination are the principal pollution problem for almost all inland lakes in world. Phytoremediation is one of the viable solutions for this concern. The present study analysed the concentration and distribution of six metals (cadmium, chromium, copper, nickel, lead and zinc) in sediment and macrophyte samples of Varthur Lake, Bangalore. Higher concentrations of studied metals in sediment were observed at the inlet and north shoreline regions of the lake. Alternanthera philoxeroides and Eichhornia crassipes accumulated higher concentration of metals than other species. Accumulation of metals in the sediment were Cu > Zn > Cr > Ni > Pb > Cd, whereas the order in macrophyte samples was Cu > Zn > Cr > Pb > Ni > Cd. Bioconcentration factor (BCF) and translocation factor (TF) of metals in macrophytes revealed metal pollution could be remediated through phytoextraction and phytostabilization.

Potential bioremediation effects of seaweed Gracilaria lemaneiformis on heavy metals in coastal sediment from a typical mariculture zone.

Seaweeds are good bio-monitors of heavy metals pollution in coastal seawater. In the present study, the potential bioremediation effects of cultivated Gracilaria lemaneiformis on heavy metals in Nan'ao coastal sediment from a typical mariculture zone, South China were evaluated. Sediment samples were collected from five different zones (Gracilaria cultivation zone, G; Fish culture zone, F; Shellfish culture zone, S; Transition zone, T; Control zone, C) from December 2014 to July 2015. The concentrations of Cd, Pb, Cu, and Zn in the sediments were significantly different among the various types of mariculture areas. The concentrations varied widely: Cd (0.04-1.02) μg g-1; Cu (1.19-37.70) μg g-1; Pb (8.45-74.45) μg g-1; Zn (36.80-201.24) μg g-1. The lowest heavy metal concentrations in the sediment were occurred at Gracilaria cultivation zone, while higher concentrations occurred at control zones and fish culture zones. The pollution load index, principal components and cluster analysis showed that heavy metal concentrations were the highest at fish culture zone, while the concentrations were the lowest at Gracilaria cultivation zone, and Gracilaria cultivation affects the heavy metals in the sediments. Gracilaria had strong adsorption capacities for heavy metals from seawater, showing the highest heavy metal Bioconcentration Factors in May (higher seaweed biomass period). Consequently, the results suggested that Gracilaria cultivation influences the heavy metal concentrations in sediments from the typical coastal mariculture zone. Gracilaria cultivation has the potential to bioremediate heavy metals in the coastal sediments. Therefore, Gracilaria cultivation can add environmental advantages and ecological values to coastal mariculture zones.

Honeybees (Apis mellifera L.) as a Potential Bioindicator for Detection of Toxic and Essential Elements in the Environment (Case Study: Markazi Province, Iran).

Honeybees, due to their wide-ranging foraging behaviour, have great potentials for monitoring environmental quality. Therefore, the purpose of this study was to use honeybees as bioindicators for the detection of toxic and essential metals (Cd, Cr, Cu, and Fe) in the environment. Totally, 180 soil, plant (including root and aerial part), honeybees, and honey samples were collected from 12 sites within the main beekeeping and honey production regions in Markazi Province, Iran in 2016. After acid digestion of samples, the metal concentrations were measured by inductively coupled plasma-optical emission spectrometers. The translocation factor (TF), and bioconcentration factor (BCF) of metals were computed. The results showed that among the analyzed bee samples, Cd (mgkg-1) was detected in amounts ranging from 0.01 to 2.35, Cr (mgkg-1) ranged from 0.02 to 18.10, Cu (mgkg-1) ranged from 2.00 to 39.11, and Fe (mgkg-1) ranged from 163 to 1695. BCF and TF values obtained showed that the Astragalus gossypinus would have a great accumulation ability for Cd and Cr. The results indicated that honeybees could be used to detect the spatial patterns of metal contaminations in the environment they dwell in.