Bioaccessibility of Cd,Cr, Cu,Mn, Ni,Pb, and Zn in Mediterranean mussel (Mytilus galloprovincialis Lamarck, 1819) along the southeastern Black Sea coast

The adverse effect of seafood consumption on human health is related to the bioaccessibility in contrast with the total heavy metal level in the tissues. In this study, bioaccessibility of Cd, Cr, Cu, Mn, Ni, Pb, and Zn in Mediterranean mussel (Mytilus galloprovincialis Lamarck, 1819) edible soft tissues collected along the southern Black Sea coast were investigated using in vitro digestion model. Total Pb concentration in the tissues was found to be higher than the maximum permissible limits set by European Commission. The bioaccessibility of metals in the tissues was found to be decreased in the order: Ni (83.11%) > Cu (80.47%) > Zn (76.86%) > Cd (73.32%) > Mn (69.11%) > Pb (61.07%) > Cr (58.44%). While significant positive linear regression was observed between total and bioaccessible concentrations for Mn, Pb, and Ni, significant negative linear regression was found for Cd (p < .05). The hazard quotients (HQ) calculated using bioaccessible amount were detected lower than the limit (HQ <1), which may not pose a potential hazard to humans reported by US Environmental Protection Agency. In sum, mussel consumption from sampling sites may cause a potential risk concerning human health especially for Cd and Pb in case of increased portion sizes.     

Effect of Glomus mosseae on accumulation efficiency,hazard index and antioxidant defense mechanisms in tomato under metal(loid) Stress

In the present study, the phytoremedation potential along with growth, physiological and biochemical response of tomato (Solanum lycopersicum) was assessed under heavy metal(loid) (HM) and arbuscular mycorrhizal fungus (AMF) amendment. Effect of AMF on uptake and accumulation of metal(loid)s was assessed and accumulation characteristics were expressed in terms of bioabsorption coefficient (BAC), bioconcentration factor (BCF), translocation factor (TLF) and transfer factor (TF). Results showed that AMF-inoculated plants showed not only a better growth, chlorophyll content, strengthened non-enzymatic and enzymatic defense mechanism, but also accumulated higher concentration of metal(loid)s. The correlation between biochemical and physiological parameters was significant at 0.01 level. A significant difference (p ≤ 0.001) in antioxidant enzyme activity was found on increasing metal(loid) dose and application of AMF. The accumulation of Cd and Pb in edible part exceeded the chronic reference dose stated by USEPA. The target hazard quotient (THQ) was >1 for Cd and Pb, whereas <1 for As. The study shows that tomato has good potential as Cd and Pb phytoremediator, hence must not be consumed when grown on Cd or Pb contaminated sites.     

Bioaccessibility of heavy metals in rapa whelk Rapana venosa (Valenciennes, 1846): Assessing human health risk using an in vitro digestion model

Instead of total metal concentration measurements in seafood, bioaccessibility is a more important parameter for human health risk assessment. Therefore, bioaccessibility of Cd, Cr, Cu, Mn, Ni, Pb, and Zn in the edible soft tissues of rapa whelk (Rapana venosa Valenciennes, 1846) collected along the southern Black Sea coast were investigated using an in vitro digestion model. Zn was detected at the highest concentration, whereas Ni was the lowest for total metal concentrations. Total Cd and Pb concentration in the tissues were found to be higher than maximum permissible limits set by European Commission. The bioaccessibility of metals in the tissues was found to be decreased in the order: Cu (77.11%) > Cd (70.13%) > Zn (64.52%) > Ni (61.27%) > Pb (50.53%) > Cr (43.41%) > Mn (22.59%). While significant positive linear regressions were observed between the total and bioaccessible concentrations for Mn, Pb, and Ni, significant negative linear regressions were found for Cd in the tissues (p < 0.05). The hazard quotients (HQ) calculated using bioaccessible heavy metal amount were detected lower than the limit value (HQ < 1), which may not pose a potential hazard to humans declared by US Environmental Protection Agency. However, the consumption of rapa whelk may cause a potential risk concerning human health for the Cd and Pb levels in case of increased serving sizes and portions.     

Heavy Metals in Mussels (Mytilus galloprovincialis) from Marmara Sea, Turkey

Marmara Sea is one of the main catching areas of mussels (Mytilus galloprovincialis) in Turkey, and a significant portion of the harvest has been exported mainly to European countries. In this study, Zn, Cu, Cd, Hg, and Pb in mussels from ten catching areas in Marmara Sea were analyzed to investigate health risks associated with consuming mussels. Mercury was not detected (<0.15 ppb) in any of the samples. The highest concentrations of Cu and Cd were 3.473 and 0.740 mg kg^?1 (wet weight, WW), respectively, well below the maximum permissible levels. All samples contained Zn higher than 50 mg kg^?1, while Pb was above the limits in the samples from stations 1, 4, 6, and 8. Mussels from Marmara Sea are safe regarding Cu, Cd, and Hg but may contain Zn and Pb above the permissible limits. However, metal contents of mussels from Marmara Sea are mostly lower than those of the regions in other areas of the world. It was concluded that Marmara Sea has a potential of being a safe source of mussels if industrial inputs somewhat reduced and controlled. Concentrations of heavy metals in mussels must be monitored comprehensively and periodically with respect to the consumer health.     

Phytochelatin–metal(loid) transport into vacuoles shows different substrate preferences in barley and Arabidopsis

Cadmium (Cd) and arsenic (As) are toxic to all living organisms, including plants and humans. In plants, Cd and As are detoxified by phytochelatins (PCs) and metal(loid)‐chelating peptides and by sequestering PC–metal(loid) complexes in vacuoles. Consistent differences have been observed between As and Cd detoxification. Whereas chelation of Cd by PCs is largely sufficient to detoxify Cd, As–PC complexes must be sequestered into vacuoles to be fully detoxified. It is not clear whether this difference in detoxification pathways is ubiquitous among plants or varies across species. Here, we have conducted a PC transport study using vacuoles isolated from Arabidopsis and barley. Arabidopsis vacuoles accumulated low levels of PC₂–Cd, and vesicles from yeast cells expressing either AtABCC1 or AtABCC2 exhibited negligible PC₂–Cd transport activity compared with PC₂–As. In contrast, barley vacuoles readily accumulated comparable levels of PC₂–Cd and PC₂–As. PC transport in barley vacuoles was inhibited by vanadate, but not by ammonium, suggesting the involvement of ABC‐type transporters. Interestingly, barley vacuoles exhibited enhanced PC₂ transport activity when essential metal ions, such as Zn(II), Cu(II) and Mn(II), were added to the transport assay, suggesting that PCs might contribute to the homeostasis of essential metals and detoxification of non‐essential toxic metal(loid)s.     

Metal residues in flesh of edible blue crab,Callinectes amnicola,from a tropical coastal lagoon: Health implications

Metals such as cadmium (Cd), lead (Pb), zinc (Zn), and copper (Cu) were estimated in the flesh of the edible blue crab Callinectes amnicola from selected areas of the Lagos Lagoon, Nigeria (i.e., Makoko, Iddo, Okababa, Ikoyi, and Ajah) for 18 months between March 2011 and August 2012. Estimated average daily intake (EADI) and target hazard quotient (THQ) were used to determine the risk implications for adult and child consumer populations. Range of Cd, Pb, Zn, and Cu across sites was 0.16–0.46, 1.48–3.17, 2.21–3.65, and 9.48–12.76 mg kg^?1 crab flesh wet weight, respectively. Lead concentrations in crab flesh from Makoko (3.16 ± 1.44 mg kg^?1) and Iddo (5.17 ± 1.26 mg kg^?1) exceeded the maximum accepted limits recommended by the Food and Agriculture Organization/World Health Organization for food fisheries. The EADI across sites for the adult consumer population exceeded the reference dose (RfD) recommended by the U.S. Environmental Protection Agency for most metals with magnitude of ≤7-fold while EADI of Pb among child consumer population across sites exceeded RfD by a maximum of 4.5-fold. THQs for adult population were >1 for all metals across all sites, and >1 for Pb and Cd for selected sites for the child consumer population. Findings from this study indicate higher health risks of metal toxicity to adult consumer populations, and risks of lead toxicity to child consumer populations around the Lagos Lagoon, Nigeria.     

Human health risks of metalloids and metals in muscle tissue of silver carp Hypophthalmichthys molitrix (Valenciennes, 1844) from Lake Flag Boshielo,South Africa

The Olifants River, a major tributary of the Limpopo River, is one of the most polluted rivers in South Africa. Consequently, concerns regarding the human health impact of long-term consumption of fish from the Olifants River have been raised in recent studies. Nevertheless, Lake Flag Boshielo situated on the main stem of the Olifants River has been proposed as a site for an inland fishery. Planktivorous silver carp Hypophthalmichthys molitrix (Valenciennes, 1844) is among the potential target species for such a fishery. Therefore, a desk-top human health risk assessment was conducted for silver carp from Lake Flag Boshielo. From January to November 2013, muscle samples from 50 specimens were collected and analysed for metals and metalloids. The hazard quotient based on a weekly meal of 150 g exceeded the acceptable level for As, Cd, Cr, Co, Pb, Hg, Se, V and Zn. Compared with previous studies from Lake Flag Boshielo, muscle tissue concentrations of As, Cr, Pb, Hg, Se, V and Zn for H. molitrix were higher. Based on the metal and metalloid concentrations reported in this study, long-term consumption of silver carp from Lake Flag Boshielo might pose a health risk to impoverished rural communities.     

Biomonitoring of metal(oid)s in mining-affected Borcka Dam Lake coupled with public health outcomes

Due to increased anthropogenic activities, the aquatic environment is exposed to pollutants much more than ever. These pollutants go into the food chain and can pose a health risk to human. Correlatively, Borcka Dam Lake, Turkey has been affected by mining activities since decades. In the present study, therefore, Cu, Pb, As, Zn, Mn, Cd, Cr, and Se concentrations in water, sediment, and different tissues (muscle, gill, liver) of 11 fish species sampled from the lake were analyzed regarding metal(oid)s pollution and potential human health risk through fish consumption. The metal(oid) concentrations in the water were below the limit values recommended by USEPA for aquatic life criteria but sediments were heavily polluted by As, Cu, Pb, and Zn based on Sediment Quality Guideline. The lowest metal(oid) values among tissues for all fish species were determined in muscle (p < 0.05) which was lower than the limits for human consumption declared by European Union Regulation. Target Hazard Quotient and Hazard Index used non-cancer risk estimate which was lower than 1. In the view of these results, the consumption of fish caught from the Borcka Dam Lake may not pose a potential risk to human.     

Biodiversity of Zoobenthos in the Coastal Zone of the South Coast of Crimea (Laspi Bay Area)

Based on data of a1996 benthos survey, the structure of soft bottom zoobenthos of Laspi Bay (South Coast of Crimea, the Black Sea) was examined. One hundred thirty-one species of macrozoobenthos, including 44 molluscan species, 43 annelids, 31 crustaceans and 13 species representing other groups, were recorded. Two biocenoses were distinguished: Chamelea gallina and Mytilus galloprovincialis within the depths 5–52 m. The first biocenosis was presented by two biocenosic complexes. Their structure was characterized using Shannon, Simpson, and Pielou indices. The representativeness of the basic taxonomic groups of the benthos was analyzed. The conclusion of the high species abundance of benthos in Laspi Bay was made. There were recorded changes in structure of the biocenoses, which were manifested in the development of sestonophage filterers (first of all, the mollusc Chamelea gallina) with increasing organic pollution of the coastal water areas of Black sea.     

Assessment of heavy metal in the water,sediment, and two edible fish species of Jamshedpur Urban Agglomeration,India with special emphasis on human health risk

The city of Jamshedpur, nicknamed the “industrial capital of Jharkhand,” is one of the oldest industrial settlements in India, nestled amidst the mineral-rich Chota Nagpur plateau, with its diverse tribal population. Heavy metal contamination from industrialization and urbanization can pose a serious health risk to the resident population of the city. Metal concentrations in water and sediment of various water bodies (rivers, canals, and lakes) were determined using ICP-MS. Pollution indices indicate heavy metal contamination at Jamshedpur Urban Agglomeration, mainly because of Cr (23–1111.6 mg/kg), Hg (0.08–4.11 mg/kg), and Pb (5.2–248 mg/kg). Labeo rohita and Punitus sarara, the two popular edible fishes, also have high concentration of Cr, Hg, and Pb. Health risk to human population due to consumption of metal contaminated edible fishes (L. rohita and P. sarara) was determined by target hazard quotient (THQ) and hazard index (HI). THQ value of fish consumption (most popular protein supplement in the area) was found higher for Cr and Pb when compared with previous literature on fish consumption. Also, HI value ranged from 1.4 to 3.9, suggesting that the children have higher health risks than adults, due to consumption of metal contaminated fishes (especially L. rohita).     

Sources and Ecological Risk Assessment of Heavy Metal(loid)s in Agricultural Soils of Huzhou,China

To identify sources of heavy metal(loid) (HM) contamination in agricultural soils of Huzhou, surface soil samples were sampled from 89 different agricultural regions in 2012. Concentrations of heavy metal(loid)s, along with pH, total phosphorus (TP), total nitrogen (TN), and soil organic matter (SOM), were determined. Ecological risk was then assessed using a modified Hakanson ecological risk index, and the sources of contamination were determined using principal component analysis (PCA). Mean concentrations of heavy metal(loid)s were 10.26, 23.21, 83.75, 22.81, 0.25, 61.86, 33.03, and 0.15 mg kg^?1 for As, Cu, Zn, Ni, Cd, Cr, Pb, and Hg, respectively. Cu, Zn, Ni, Cr, Cd, Hg, and Pb were correlated positively with TP and there were obvious positive correlations among Cu, Zn, Ni, Cr, and Cd. Risk index (RI) values varied from 39 to 1246 with a mean value of 137. Enrichment of Pb, Zn, Cu, and especially Cd can be attributed to excessive use of nitrogen and phosphorus fertilizers containing heavy metals, as well to surface irrigation and natural soil formation. While the ecological risk of most agricultural soils in Huzhou is low, it is recommended that the use of phosphate and nitrogen fertilizers be restricted and production technology be improved to reduce the heavy metal(loid) concentrations. Results suggest that the Chinese environmental quality standard for soil should be revised to better address heavy metal(loid) contamination.     

Accumulation of Trace Metals by Mangrove Plants in Indian Sundarban Wetland: Prospects for Phytoremediation

The work investigates on the potential of ten mangrove species for absorption, accumulation and partitioning of trace metal(loid)s in individual plant tissues (leaves, bark and root/pneumatophore) at two study sites of Indian Sundarban Wetland. The metal(loid) concentration in host sediments and their geochemical characteristics were also considered. Mangrove sediments showed unique potential in many- fold increase for most metal(loid)s than plant tissues due to their inherent physicochemical properties. The ranges of concentration of trace metal(loid)s for As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb and Zn in plant tissue were 0.006–0.31, 0.02–2.97, 0.10–4.80, 0.13–6.49, 4.46–48.30, 9.2–938.1, 0.02–0.13, 9.8–1726, 11–5.41, 0.04–7.64, 3.81–52.20 μg g ^?1respectively. The bio- concentration factor (BCF) showed its maximum value (15.5) in Excoecaria agallocha for Cd, suggesting that it can be considered as a high-efficient plant for heavy metal bioaccumulation. Among all metals, Cd and Zn were highly bioaccumulated in E. agallocha (2.97 and 52.2 μg g ^?1 respectively. Our findings suggest that the species may be classified as efficient metal trap for Cd in aerial parts, as indicated by higher metal accumulation in the leaves combined with BCF and translocation factor (TF) values.     

Estimating the Productivity of the Black Sea Bivalve Chamelea gallinafrom the Size and Biomass of Its Populations

Characteristics of annual production based on various mass data (whole animal mass; shell mass; and wet, dry, and ash-free dry soft tissue mass), the P/B coefficient, and specific production were estimated for the bivalve mollusk Chamelea gallinasampled from 21 localities in the northwestern and eastern Black Sea. The annual production correlated with population biomass (r= 0.994) and mean individual mass (r= –0.737), while the P/Bcoefficient depended mainly on mean individual mass (r= –0.719). Estimates of the P/Bcoefficient in Ch. gallinafrom the Black Sea were smaller than those of other marine invertebrates found worldwide with the same energy equivalent. Multiple linear regression equations were calculated for empirical relationships of various characteristics of annual production to the population biomass and mean individual biomass of Ch. gallina.     

Toxic metal ion in seafood: Meta-analysis of human carcinogenic and non-carcinogenic threat assessment,a geomedical study from Dhamra and Puri,Odisha

The investigation revealed the adverse health threats on human beings from toxic metals via ingestion of seafood from two contaminated sites in Odisha. Bioaccumulation through food chain was presented as tissue metal concentrations. The non-carcinogenic and carcinogenic health hazards were estimated by Target Hazard Quotient (THQ) and Target Cancer Risk (TCR) following USEPA referred safe metal intake limit. THQ of Metals like Mn, Ni, Cd, Pb in both sites showed >1, indicating a severe non carcinogenic health threat to humans from the investigated metals. THQ of Cu, Zn, Fe, Cr and Hg showed < 1, implying the least possible deleterious health effects. Cr was the most significant carcinogenic pollutant in both sites. The marine fish consumption of Dhamra site might cause extra 7 cases of cancer per 10000 populations due to higher Cr level (cancer risk 6.7 × 10^?3). Carcinogenic risk of Ni and Pb were below the tolerable range of 10E-4. The presence of Cd in sea foods elevated cancer risks in both sites. The metal pollution index (MPI) indicated, the highest toxic metal bio accumulation was contributed by Arius arius species. Ilisha megaloptera and Lates calcarifer from Dhamra and Puri showed highest hazard index (HI) suggesting unaccountable non-carcinogenic health threat.     

Evaluation of trace metals in sediment,water, and fish (Mugil cephalus) of the central Black Sea coast of Turkey

In this study, concentrations of trace metals such as As, Cd, Cu, Cr, Fe, Pb, Ni, Sn, Se, and Zn were determined in sediments, water, and a kind of fish (Mugil cephalus) of the central Black Sea coasts by employing Inductively Coupled Plasma Mass Spectrometry and microwave digestion technique. Gill, muscle, liver, and other tissues were analyzed separately for each sample. The accuracy of the results were checked by using a certified reference material (DORM-4). In water samples, the metal determined at highest concentrations was Cu (1645.44 µg/L). In sediment samples, the metal determined at highest concentrations was Fe (12223.50 mg/kg). The levels of trace metals found in the different parts of the fish were: Zn in muscle tissue (30393.28 mg/kg), Sn in gill tissue (5140.08 mg/kg), and Cu in liver tissue (289.31 mg/kg). These results were also compared with various relevant guidelines and literature.     

A preliminary health risk assessment of heavy metals in local and imported rice grains marketed in Trinidad and Tobago,W.I.

Abstract

Within recent times, heavy metal contamination in rice (Oryza Sativa) has been of growing concern particularly due to its implications on human health via consumption. Twenty-one different brands of rice marketed in Trinidad and Tobago were investigated for their heavy metal content (Cd, Cr, Cu, Mn, Ni, Pb and Zn) using Flame Atomic Absorption Spectroscopy. Lead was not detected in any of the samples, while both Cadmium and Nickel were detected in only one sample each at 0.27 and 1.79?µg/g, respectively. The average metal concentrations decreased in the following order: Zinc?> Manganese?> Copper?>?Chromium with concentrations ranging from 1.00–4.35, 1.72–29.92, 5.87–43.56 and 0.06–1.16?µg/g, respectively. The target hazard quotient (THQ) and hazard index (HI) values for all samples were less than one, indicating no risk of non-carcinogenic effects to consumers.     

Metal(loid)-Contaminated Soils as a Source of Culturable Heterotrophic Aerobic Bacteria for Remediation Applications

Heavy metal–contaminated soils are a serious environmental problem. Herein, the culturable heterotrophic bacterial community present on two metal(loid)-contaminated sites in the Northern Portugal was investigated. The bacterial counts ranged from 5.96 to 7.69 and 7.04 to 7.51 (log CFU g^?1 soil) in Sites 1 and 3, respectively. The bacterial population was predominantly composed of Firmicutes, Proteobacteria, and Actinobacteria on both sites. The most represented genera in Site 1 were Bacillus (41%) and Pseudomonas (27%), whereas Arthrobacter (21%) and Pseudomonas (13%) were the most represented genera in Site 3. Several bacterial isolates showed tolerance to high concentrations of metal(loid)s, suggesting that both contaminated sites are a valuable source of metal(loid)-tolerant bacteria, which may be further used in bioremediation and/or phytoremediation processes.     

Drinking water quality and risk implications for community health: A case study of shallow water wells and boreholes in three major communities in Northern Cross-River,Southern Nigeria

The quality of water sources and its potential health implications to adults and children populations of respective major communities in Northern Cross-River was assessed. Water samples (n = 10/water source/site) were collected from three (Okpoma, Okuku and Ugaga) communities and heavy metal concentrations (Lead (Pb), Cadmium (Cd), Chromium (Cr), Manganese (Mn), Nickel (Ni), Copper (Cu), Cobalt (Co), and Zinc (Zn)) were evaluated using Atomic Absorption Spectrometer (AAS). Overall, Pb, Cd, Ni, and Co were higher than drinking water guidelines, while only Cr, Mn, Cu, and Zn were within the permissible limits. The estimated average daily intake (EADI) and target hazard quotient (THQ) were used to determine risk implications for adult and children consumer populations. The EADI for Pb in adults for borehole water, Pb and Cr by child consumer population for borehole and shallow well water exceeded the reference dose (RfD) by USEPA. The THQ for adult population were >1 for Pb in borehole water and >1 for Pb and Cr across all sites for the child consumer population. Overall, our findings indicate toxicity and higher hazard risk for both adult (Pb) and children (Pb and Cr) populations that source drinking water from borehole and shallow well water in these communities.     

Characterization of Pb and Cd contamination in the feces and feathers of rook (Corvus frugilegus) and the scalp hair of residents in Qiqihar,northeastern China

The concentrations of Pb and Cd, and trace elements (Cu and Zn) in the urban topsoil, rook (Corvus frugilegus) feces and feathers and human scalp hair were analyzed to examine the potential ecological risk posed by Pb and Cd on local residents of Qiqihar City, northeastern China. Results revealed that the Cd concentrations in the topsoil were ranged from 0.14 to 3.55 mg kg^?1 dry weight (dw). The maximal geoaccumulation indices [a value from logarithmic (a measured metal content/1.5 × background content of the metal in this region), introduced by Muller] of Cd exceeded 3.5, which suggested that this region was seriously contaminated by Cd. The corresponding average detectable concentrations in C. frugilegus feathers and feces were 1.38 and 3.97 mg kg^?1 dw for Pb and 1.04 and 0.69 mg kg^?1 dw for Cd. High Pb and Cd concentrations, respectively, ranging from 7.46 to 24.9 mg kg^?1 dw and from 0.35 to 0.92 mg kg^?1 dw were also detected in the human scalp hair samples. These high Pb and Cd concentrations in C. frugilegus and local people were possibly associated with local industrial wastes and vehicle exhausts. The external tissues (feces and feather) of the rook species can be considered as an indicator of potential Cd toxic risk in this species; however, the human scalp hair is not a reliable biomarker for risk of Pb and Cd in the human being. Effective measures should be established to reduce the inputs of Pb and Cd into the urban environment and to protect the health of local people.     

Phylogenetic analysis of Veneridae (Bivalvia): Comparison of molecular and palaeontological data

An approximately 400-by-long portion of the 16s rRNA gene sequence has been determined for the venerid clamsChamelea gallina (Chioninae),Dosinia lupinus (Dosiniinae),Pitar rudis,Callista chione (Pitarinae),Tapes decussatus,T. philippinarum,Venerupis (=Paphia)aurea (Tapetinae), andVenus verrucosa (Venerinae). Neighbor-joining and maximum parsimony trees support the results of traditional classification methods at the subfamily level but do not support the concept of a genusTapes. The transversion divergence rate estimated on the basis of the palaeontological record for theC. gallina/V. verrucosa separation and for the Pitarinae is very close (0.14–0.16% per Myr, respectively) to that of ungulates and cetaceans, while the Tapetinae exhibit a much higher (0.36% per Myr) rate. Correspondence to: E. Olmo