Source analysis and health risk of heavy metals in the different seasons from Taizihe River,China

Twenty five water samples were collected along the Taizihe River, the concentration and health risks of Zn, Cu, Pb, Cr and Cd were detected and evaluated, and the pollution sources was analyzed through principal components analyses. The results indicated that the order of average concentration of heavy metals was follows: Pb > Cr > Cu > Zn and Cd. Among that, the concentrations of Zn, Cu and Cr were at the permissible levels, but Pb and Cd exceeded grade V standard at some sites. The concentrations of Zn and Cu in the wet season were significant higher than that in the dry season (p < 0.05), but the average concentrations of Pb, Cr and Cd were not significantly different in the two seasons (p > 0.05). The annual average risks of human health caused by Cd and Cr were 10⁻³/a and 10⁻⁴/a, respectively, which were higher than the recommended maximum acceptable risk level. The human health risk values of Zn, Pb and Cu were all concentrated at 10⁻⁸/a or 10⁻⁹/a levels, which did not exceed the recommended standard. On the whole, Cd and Cr were the main health risk pollutants of Taizihe River. Pollution sources of Pb was different from other heavy metals in wet and dry season, Cd and Cr were similar in the wet and dry season. The mainly pollution source of heavy metals was industry, especially mining, metal smelting and electroplating industry.     

Bioaccumulation of heavy metals in the different tissues of Mackerel scad,Decapterus macarellus (Cuvier, 1833) collected from Karachi and Gwadar Coasts of Pakistan

IntroductionAmong other aquatic animals, fish can also accumulate a large number of toxic metals in their various body organs, which may enter in the human body and cause serious health issues. Therefore, the basic aim of this study was to observe the level of some heavy metals (i.e., Pb, Fe, Cu, Cd, Cr) found in the different tissues of Decapterus macarellus collected from the Karachi and Gwadar coasts of Pakistan.MethodsAbout 200 fish samples of five different size groups of Decapterus macarellus were collected from Gwadar and Karachi fish harbors during April to September 2020. Total 10 samples of each size group i.e., S1, S2, S3, S4 & S5 were collected from each coast. Heavy metals were analyzed in fish samples by using the atomic absorption spectrophotometer (AAS).ResultsThe overall results revealed that some metals like Cu, Pb, Cd & Cr contents were high in the stomach, while less in the muscles. Whereas, the concentration of Fe was found to be high in the liver, while low in skin of fish. The average values of bioaccumulation of these heavy metals (BAF) were found in decreasing order of Cu > Cd > Fe > Cr > Pb. In this study, except Cd and Cr, all metals were found within the permissible limits. Both sediment and water from the selected site areas were also analyzed to observe their pollution levels in the order of; sediment > water > fish tissues.ConclusionThus, it was concluded that the Karachi environment was much more polluted than the Gwadar environment because it is in an industrial unit and a busy sea site for trade. Moreover, consuming muscles from this species is safe for human health except for iron toxicity, but the use of the liver is not beneficial for all selected metals. Thus, the present work will also be helpful to monitor these toxic metals in a food chain and maintain a healthy life, and reduce all kinds of health risks associated with them.     

Trace Element Level in Different Tissues of <Emphasis Type="Italic">Rutilus frisii kutum</Emphasis> Collected from Tajan River,Iran

Tajan River is among the most significant rivers of the Caspian Sea water basin. In this study, the concentration of Cr, Cu, Fe, Mn, Ni, Pb, Cd, and Zn were determined in brain, heart, liver, gill, bile, and muscle of Rutilus frisii kutum which has great economic value in the Mazandaran state. Trace element levels in fish samples were analyzed by means of atomic absorption spectrometry. Nearly all non-essential metals levels (Ni, Pb, Cd) detected in tissues were higher than limits for fish proposed by FAO/WHO, EU, and TFC. Generally, non-essential metals (Ni, Pb) were so much higher in muscle than the essential metals (Cu, Zn, and Mn) except Fe, which was higher than other metals in nearly all parts, except in gills. Fe distribution pattern in tissues was in order of heart > brain > liver > muscle > bile > gill. Distribution patterns of metal concentrations in the muscle of fish as a main edible part followed the sequence: Fe > Pb > Ni > Cu > Mn > Zn > Cd.     

Determination of water quality,and trace metals in endemic Sarotherodon linellii,Pungu maclareni and Clarias maclareni,in crater Lake Barombi Mbo,Cameroon

Considering water pollution as a potential threat to some endemic cichlids of Lake Barombi Mbo, Cameroon, an investigation was done in 2011 to determine trace metals in its water, linking their uptake in gills and liver of fish to water chemistry. ICP-MS and ICP-OES analyses of trace metals based on total concentration of unfiltered lake water samples showed the presence of trace metals. All fish species accumulated Al, Mn and Sr in the highest concentrations in their gills, with Cu, Cd, Co, Cr, Pb and U highest in the liver. Pungu maclareni accumulated Al, Cr, Co, Sr and Pb in the highest concentrations. The highest mean gill Al concentration of 140 µg g^?1 dry weight was measured in P. maclareni gills, this being one of the critically endangered cichlids of the lake. Stable isotope analyses of carbon δ¹³C and nitrogen δ¹⁵N showed that P. maclareni had the highest mean δ¹³C (?30.2‰) and highest concentrations of Cr, Co, Pb and U in liver, probably linking the carbon source to the accumulation of metals. Though trace metal levels in the lake water were low, their presence in fish tissues suggest they are bioavailable, bioaccumulate and may pose a threat to the aquatic biota, and therefore should be monitored.     

Impact of Land-Use Patterns on Chemical Properties of Trace Elements in Soils of Rural,Semi-Urban,and Urban Zones of the Niger Delta,Nigeria

The study of the concentrations of Cr, Zn, Cd, Pb, Ni, and Cu in soils under different land uses in rural, semi-urban, and urban zones in the Niger Delta was carried out with a view to providing information on the effects of the different land uses on the concentrations of trace elements in soils. Our results indicate significant variability in concentrations of these metals in soils under different land uses in rural, semi-urban, and urban zones. The maximum concentrations of metals in the examined soil samples were 707.5 mg.kg^?1, 161.0 mg.kg^?1, 2.6 mg.kg^?1, 59.6 mg.kg^?1, 1061.3 mg.kg^?1, and 189.2 mg.kg^?1 for Cr, Zn, Cd, Pb, Ni, and Cu, respectively. In the rural zone, the cassava processing mill is a potent source of Ni, Cr, Cu, and Zn while agricultural activities are a source of Cd, and automobile emissions and the use of lead oxide batteries constitute the major sources of Pb. In the urban zone, soils around the wood processing mill showed elevated concentrations of Cu, Cr, Zn, and Ni, while soils around automobile mechanic works and motor parks showed elevated levels of Pb. Elevated Cd concentrations were observed in soils under the following land uses: urban motor park, playground, welding and fabrication sheds, and metallic scrap dump. The contamination/pollution index of metals in the soil follows the order: Ni > Cd > Cr > Zn > Cu > Pb. The multiple pollution index of metals at different sites were greater than 1, indicating that these soils fit into “slight pollution” to “excessive pollution” ranges with significant contributions from Cr, Zn, Cd, Ni, and Cu.     

Metal enrichment in water and fish in a semi-urban Nigerian lake,and their associated risks

Trace metal (Zn, Pb, Cu, Cr and Cd) concentrations in the water column and in the liver, muscle and gill tissues of Parachanna obscura and Clarias gariepinus in Agulu Lake, Nigeria, were investigated in June 2014 and compared with WHO and FAO safe limits for water and fish. Hazard index (HI) values were estimated to assess the potential public health risk of consuming contaminated fish. Lead and cadmium exceeded WHO guideline values for drinking water. In most cases, variations in concentration of the metals in organs were liver > muscle > gill. Differences in tissue-specific concentrations between species were not significant, except for zinc in muscles and gills. Cadmium and chromium were not detected in the fish, but lead was above the FAO maximum value for consumption. Hazard index values were below 1, indicating a low risk to public health. However, trace metal contamination in Agulu Lake is increasing.     

From water to edible fish. Transfer of metals and metalloids in the San Roque Reservoir (Córdoba,Argentina). Implications associated with fish consumption

The concentration of Mn, Fe, Zn, Cu, Cd, Cr, Ni, Ag, Mo, Nd, Al, Ce, As, Sr, Pb, Pt and Hg was analysed in water, sediments, and aquatic organisms from the San Roque Reservoir (Córdoba-Argentina), sampled during the wet and dry season, to evaluate their transfer through the food web. Stable nitrogen (δ¹⁵N) isotopes were used to investigate trophic interactions. According to this, samples were divided into three trophic groups: plankton, shrimp (Palaemonetes argentinus) and fish (Silverside, Odontesthes bonariensis). Liver and gills are the main heavy metal storage tissues in fish. Hg and As concentrations in the muscle of O. bonariensis exceed the Oral Reference doses for metals established by USEPA (2009). Trophic magnification factors (TMFs) for each element were determined from the slope of the regression between trace element concentrations and δ¹⁵N. Calculated TMFs showed fundamental differences in the trophodynamics of the studied elements during the wet and dry season in the San Roque Reservoir. Concentrations of Ni, Cd, Cr, Al, Mn, Fe, Mo, Ce, Nd, Pt and Pb during both seasons, and Sr during the dry season, showed statistically significant decreases (TMF < 1) with increasing trophic levels. Thus these elements were trophically diluted in the San Roque food chain. Conversely, Cu, Ag and As (dry season) showed no significant relationships with trophic levels. Among the elements studied, Hg in the wet season, and Zn in the dry season were the only ones showing a statistically significant increase (TMF > 1) in concentration with trophic level. Current results trigger the need for further studies to establish differential behaviour with different species within the aquatic web, particularly when evaluating the transfer of toxic elements to edible organisms, which could pose health risks to humans.     

Heavy Metals in Eight Edible Fish Species from Two Polluted Tributaries (Aik and Palkhu) of the River Chenab,Pakistan

Concentration of heavy metals (lead (Pb), cadmium (Cd), chromium (Cr), and copper (Cu)) was determined in the liver, gills, kidneys, and muscles of eight edible fish species (Channa punctata, Cirrhinus reba, Labeo rohita, Heteropneustes fossilis, Mystus cavasius, Oreochromis niloticus, Puntius sophore, and Wallago attu) from upstream and downstream zones of the Nullah Aik and Palkhu tributaries of the River Chenab located in the Sialkot district known for its tanning industries worldwide. The pattern of metal accumulation in studied organs was in the order: Cr > Pb > Cu > Cd. Liver showed greater metal accumulation, followed by gills, kidneys, and muscles. Accumulation of Pb and Cr was significantly different in organs between upstream and downstream zones. Accumulation was greater in fish species dwelling downstream, indicating impairment of ambient stream water due to untreated discharge of industrial and municipal effluents into studied streams. Highest concentration of Pb and Cr and lowest of Cd was detected in H. fossilis whereas Cu showed higher concentration and Cr lowest concentration in P. sophore. In contrast, lower concentration of Pb and Cu was recorded in M. cavasius, O. niloticus, and W. attu. Mean concentrations of Cd, Cr, and Cu were higher in pre-monsoon compared to post-monsoon season. Measured concentrations of Pb, Cd, and Cr in muscles of species such as C. punctata, W. attu, L. rohita, P. sophore, and O. niloticus were above permissible limits of heavy metals for human consumption, indicating potential health risks. Therefore, these fish species from studied locations should be avoided for human diet.     

Distribution and bioavailability of heavy metals in different particle-size fractions of sediments in Taihu Lake,China

Abstract

Taihu Lake is one of the most important water sources in the economically developed central-eastern part of China, and metal pollution is a major concern for the lake. The distribution and bioavailability of Cd, Cr, Cu, Pb, Sb and Zn were analysed in undifferentiated bottom sediments and in various particle-size fractions of the sediment from different parts of the lake. The average concentration of total metals in undifferentiated sediments ranged from 0.86 mg kg^-1 (Cd) to 95.45 mg kg^-1 (Zn) for the entire lake, with the highest concentrations in Zhushan Bay. The concentration of heavy metals was higher in extremely fine sands (0.064–0.125 mm) and fine sands (0.125–0.25 mm) than in other fractions. Sequential extractions showed that Cu, Zn and Cd were the most bioavailable accounting for 55.6%, 38.7% and 30.0% of their total concentration, respectively. However, the bioavailable proportion of many metals was not significantly different between grain grades except for Cu and Zn, which were higher in silts (<0.064 mm) than in other grades. Compared with the background values of local soils, the concentration of Zn, Cd, Cu, Pb and Sb was higher, indicating enrichment in the sediment. From ecological safety concerns, Zn, Cd and Cu should be examined closely because of their higher bioavailabilty in the sediment.     

Histopathology and helminth parasites of African catfish Clarias gariepinus (Burchell, 1822) in relation to heavy metal pollution in a subtropical river system

In a study aimed to determine the histopathology, component parasite communities and level of selected heavy metals, African catfish Clarias gariepinus from three rivers in Zimbabwe (Gwebi, Manyame and Mukuvisi) were analysed for heavy metals (Cd, Cr, Cu, Fe, Ni, Pb, Zn) in the gills, liver, kidney and muscles. The histopathology of these tissues was assessed by microscopic examination of stained thin sections. Metazoan parasite diversity and species composition in fish along different sites of the rivers were determined and compared. Levels of Cd, Fe, Pb and Zn were lowest in the Gwebi, Cr and Cu in the Manyame, and Ni in the Mukuvisi River. There were significant differences (P < 0.5) in concentration of iron and nickel in the gill and liver tissues of fish among the three rivers while significant differences in concentration of iron and lead were observed in muscle tissue. Gill chronic inflammation and ossification were significantly different (P < 0.5) in fish from among the three rivers. Chronic inflammation, hemosiderin deposits and bile accumulation in the liver were also significantly different (P < 0.5) among the three rivers and so was the extent of chronic inflammation in the kidney tissue. Lamellar fusion was slightly more present in gills of catfish from the Mukuvisi than the Gwebi River. The parasite community of C. gariepinus comprised three monogenean, two cestode and three nematode species. The least polluted Gwebi River had the highest parasite community diversity while the most polluted Mukuvisi River had the lowest diversity. Fish parasite community structure is thus a potential indicator of river pollution, while heavy metal pollution is a potential threat to fish and human health in the system.     

Heavy metal bioaccumulation by the organs of Phragmites australis (common reed) and their potential use as contamination indicators

The concentrations of heavy metals in the roots, rhizomes, stems and leaves of the aquatic macrophyte Phragmites australis (common reed), and in the corresponding water and sediment samples from the mouth area of the Imera Meridionale River (Sicily, Italy), were investigated to ascertain whether plant organs are characterized by differential accumulation, and to test the suitability of the various organs for heavy metal biomonitoring of water and soil. Heavy metals considered were Cd, Cr, Cu, Hg, Mn, Ni, Pb, Zn. Results showed that belowground organs were the primary areas of metal accumulation. In particular, metal concentrations in plant organs decreased in the order of root > rhizome ≥ leaf > stem. All four organs showed significant differences in concentration for Cr, Hg, Mn, Zn, thus suggesting low mobility from roots to rhizomes and to aboveground organs. Although the organs followed different decreasing trends of metal concentration, the trend Mn > Zn > Pb > Cu was found in each plant organ. Mn showed the highest concentrations in all organs whereas the lowest concentrations regarded Cd and Cr in the belowground and aboveground organs, respectively. The toxic threshold was exceeded by Cr in roots, rhizomes and leaves, Mn in roots and leaves, Ni in roots. The highest average concentrations were found as follows: Cd, Hg, Pb, Zn in root, Cr, Mn, Ni in sediment, Cu in water. Positive linear relationships were found between heavy metal concentrations in all plant organs and those in water and sediment, thus indicating the potential use of such organs for pollution monitoring of water and sediment. Advantages of using plant species as biomonitors, especially Phragmites australis, were also discussed.     

Heavy metal contamination in water,soil, and milk of the industrial area adjacent to Swan River,Islamabad, Pakistan

Trace heavy metals such as Cr(III), Ni(II), Cd(II), Zn(II), Pb(II), and Cu(II) are hazardous pollutants and are rich in areas with high anthropogenic activities. Their concentrations were analyzed using atomic absorption spectroscopy, and it was found that their concentrations were several fold higher in downstream Swan River water samples of the Kahuta Industrial Triangle as compared to upstream. Heavy metal soil concentrations taken from the downstream site were 149% for Cr, 131% for Ni, 176% for Cd, 139% for Zn, 224% for Pb, and 182% for Cu when compared to samples from the upstream site. Quantitative analysis concluded that these metals were higher in milk samples collected from downstream as compared to the samples from upstream water-irrigated sites. The order of metal in milk was as Zn > Cr > Cu > Cd > Pb = Ni. Heavy metal contaminations may affect the drinking water quality, food chain, and ecological environment. It was also suggested that the toxicity due to such polluted water, soil, and milk are seriously dangerous to human health in future.     

Cd, Cu, Zn, Se, and Metallothioneins in Two Amphibians, Necturus maculosus (Amphibia, Caudata) and Bufo bufo (Amphibia, Anura)

The accumulation of cadmium, its affinity for metallothioneins (MTs), and its relation to copper, zinc, and selenium were investigated in the experimental mudpuppy Necturus maculosus and the common toad Bufo bufo captured in nature. Specimens of N. maculosus were exposed to waterborne Cd (85???g/L) for up to 40?days. Exposure resulted in tissue-dependent accumulation of Cd in the order kidney, gills > intestine, liver, brain > pancreas, skin, spleen, and gonads. During the 40-day exposure, concentrations increased close to 1???g/g in kidneys and gills (0.64?C0.95 and 0.52?C0.76; n?=?4), whereas the levels stayed below 0.5 in liver (0.14?C0.29; n?=?4) and other organs. Cd exposure was accompanied by an increase of Zn and Cu in kidneys and Zn in skin, while a decrease of Cu was observed in muscles and skin. Cytosol metallothioneins (MTs) were detected as Cu,Zn?Cthioneins in liver and Zn,Cu?Cthioneins in gills and kidney, with the presence of Se in all cases. After exposure, Cd binding to MTs was clearly observed in cytosol of gills as Zn,Cu,Cd?Cthionein and in pellet extract of kidneys as Zn,Cu,Cd?Cthioneins. The results indicate low Cd storage in liver with almost undetectable Cd in liver MT fractions. In field trapped Bufo bufo (spring and autumn animals), Cd levels were followed in four organs and found to be in the order kidney > liver (0.56?C5.0???g/g >0.03?C0.72???g/g; n?=?11, spring and autumn animals), with no detectable Cd in muscle and skin. At the tissue level, high positive correlations between Cd, Cu, and Se were found in liver (all r?>?0.80; ???=?0.05, n?=?5), and between Cd and Se in kidney (r?=?0.76; n?=?5) of autumn animals, possibly connected with the storage of excess elements in biologically inert forms. In the liver of spring animals, having higher tissue level of Cd than autumn ones, part of the Cd was identified as Cu,Zn,Cd?Cthioneins with traces of Se. As both species are special in having liver Cu levels higher than Zn, the observed highly preferential Cd load in kidney seems reasonable. The relatively low Cd found in liver can be attributed to its excretion through bile and its inability to displace Cu from MTs. The associations of selenium observed with Cd and/or Cu (on the tissue and cell level) point to selenium involvement in the detoxification of excessive cadmium and copper through immobilization.     

Assessment of Heavy Metal Enrichment,Bioavailability, and Controlling Factors in Sediments of Taihu Lake,China

Heavy metal distribution, bioavailability, and ecological risk in the surface sediment of Taihu Lake were evaluated. Samples were collected from eight representative sites in September 2011 and February 2012. In the surface sediment, average metal contents were in the order of Cr > Zn > Ni > Pb > Cu. Spatially, Zhushan Bay maintained higher Cu, Ni, and Zn contents and Xiaomeikou maintained higher Cr and Pb contents than other sites. Spatial and temporal variation were observed in the bioavailable metals determined by acid-soluble fraction of BCR extraction. The labile metals in Zhushan Bay and Xiaomeikou were quantified by diffusive gradients in thin films (DGT) and DGT-labile concentrations of Zn, Ni, Cu, Pb, and Cd were in descending order, indicating the inconsistence of labile concentrations of different heavy metals with the total metal contents and that the toxic effect of Cd in sediment should be given attention. The ecological risk assessed by Hakanson potential ecological risk index showed that Zhushan Bay suffered the most serious pollution and should be given special attention. Bioavailability of metals should be taken into account during risk assessment for more accurate estimation.     

Distribution and enrichment of heavy metals among sediments,water body and plants in Hengshuihu Wetland of Northern China

In this study, a survey for the spatial distribution of heavy metals in Hengshuihu Wetland of China was conducted. Samples were collected from three compartments, water, sediment, and reed (Phragmites communis Trin), at different sites, and their contents of heavy metals, including mercury (Hg), arsenic (As), chromium (Cr), lead (Pb), copper (Cu), zinc (Zn), and cadmium (Cd), were analyzed. The results showed heavy metals in the sediments distributed in the Buffer Zone and Wangkou Sluice area at concentrations relatively higher than those in other areas, while concentrations in the Core Zone were lower. The heavy metal concentrations of water bodies in all areas, except those for Hg and Pb, were lower than the cutoff values for the first-grade water quality that was set as the highest standard to protect the national nature reserves. The heavy metal distributions among the three compartments were significantly different, with the following order: sediment > plant > water. In the reeds, accumulated amounts of different heavy metals varied in the following order: Hg > Zn > As > Cu > Cr. Concentrations of heavy metals only showed weak correlations between the water bodies and the sediments. Concentrations of heavy metals (except Hg and Cr) had no corrections between the sediments and the reeds. The distribution of mercury indicated that it enters the lake mainly from the atmosphere and outside water bodies. The concentrations of As, Hg, Cr, Cu and Zn in different parts of the reeds were detected and their abundances were ranked in the following order: root > leaf > stem.     

Accumulation and translocation of heavy metals in the canola (Brassica napus L.)—soil system in Yangtze River Delta, China

Aims and methods

Concentrations of heavy metals such as Cd, As, Hg, Pb, Cr, Cu, Zn and Ni in different tissues (seeds, roots and shoots) of the mature canola (Brassica napus L.) plants and in the associated rhizosphere soils from Yangtze River Delta (YRD) region of China, were determined to evaluate the heavy metals’ pollution in the soils and the canola seeds, and to discuss their accumulation and translocation characteristics in canola plants. At the same time, the phytoextraction potential of the canola plant for the above heavy metals was theoretically calculated and discussed on the basis of above measured data.

Results

The results showed that the concentration ranges of Cd, As, Hg, Pb, Cr, Cu, Zn and Ni in the rhizosphere soils were 0.115–0.481, 3.40–20.5, 0.069–0.682, 9.92–27.4, 46.8–86.6, 17.7–253.3, 65.2–511.7 and 16.0–37.8?mg?kg^?1, respectively. The concentrations of Cu, Zn and Hg at some sampling sites exceeded the 2nd grade threshods of Chinese national environmental quality standard for soils. The potential ecological risk of heavy metals in the canola rhizosphere soils decreased in the order of Zhejiang > Shanghai > Jiangsu provinces. The concentration ranges of above heavy metals in the canola seeds were 0.032–0.067, 0.002–0.005, 0.001–0.005, 0.053–0.165, 0.191–0.855, 3.01–13.20, 34.82–96.95 and 0.343–2.86?mg?kg^?1, respectively, with Cu and Zn at some sampling sites exceeding the permissible concentrations in foods of China. Heavy metals’ concentrations in canola seeds didn’t increase with their increasing concentrations in the rhizosphere soils. The bioconcentration factors (BCFs) of most heavy metals in the canola seeds decreased with their increasing concentrations in the associated rhizosphere soils. The average BCFs of heavy metals decreased in the order of Zn (0.488)>Cd (0.241)>Cu (0.145)>Ni (0.038)>Hg (0.021)>Pb (0.005)=Cr (0.005)>As (0.000) in the canola seeds, Cd (1.550)>Cu (0.595)>Zn (0.422)>Hg (0.138)>Ni (0.085)>Pb (0.080)>As (0.035)>Cr (0.031) in the roots, and Cd (0.846)>Zn (0.242)>Cu (0.205)>Hg (0.159)>Ni (0.031)>Pb (0.025)>As (0.012)>Cr (0.007) in the shoots, respectively. The accumulation capacity for most of the above heavy metals in the mature canola tissues was root > shoot > seed, with the exceptions of seed > root > shoot for Zn and shoot > root > seed for Hg. Except Hg from root to shoot and Zn from root to seed, translocation factors (TFs) of above heavy metals were lower than 1.0.

Conclusions

The concentrations, BCFs and TFs of above heavy metals in the canola tissues indicated that the investigated canola plants did not meet the criteria of hyperaccumulators for the above heavy metals. The phytoextracton potential of the studied canola plants for the above heavy metals from the polluted soils was very limited. It would take 920, 3,170 and 3,762?years (assuming two crops per year) to reduce the initial soil Zn, Cu and Hg concentrations, respectively, from the most polluted soil concentrations to the 2nd grade thresholds of Chinese national environmental quality standard for soils.     

Trace elements in the muscle,ova and seminal fluid of key clupeid representatives from the Gdansk Bay (South Baltic Sea) and Iberian Peninsula (North-East Atlantic)

BackgroundBaltic herring and European sardine are pelagic, fish of particular ecological importance, on the one hand control numbers of planktonic organisms, and on the other hand exist as food for predators on higher trophic levels. Moreover, these fish are among the main species caught for human consumption. Rare earth elements (REEs) come mainly from geogenic sources but, due to their use in technology, agriculture and medicine, the importance of anthropogenic sources is growing steadily.MethodsSamples used for the study were available on the market. Fresh materials of fish muscle, ova and seminal fluid were mineralized and elements were determined by means of inductively coupled plasma – mass spectrometry (ICP-MS).ResultsThe conducted research indicated the presence of REEs in the muscles of the Baltic herring (∑REE = 0.076 ± 0.047 mg/kg) and European sardine (∑REE = 0.191 ± 0.163 mg/kg), with a clear dominance of heavy REEs in both fish species. Trace elements (TE) in the muscles of the tested fish demonstrated a similar system of concentration (Baltic herring: Zn > As > Se > Cu > Cr > Ni > Pb > Cd; European sardine: Zn > As > Se > Cu > Ni > Cr > Pb > Cd). REEs and TEs in these fish were presence in ova and seminal fluid indicates intergenerational transfer.ConclusionChanges in the concentrations of some trace elements (As, Cu, Cd) in the muscles of herring indicate increases compared to the historical data. The availability of metals in the aquatic environment may be determined by ongoing climate changes, effected water salinity and warming increased availability of labile forms of trace metals. Decline trends in the condition of pelagic fish need to extend the research in the context of contemporary environmental threats.     

Bioaccumulation of heavy metals in two morphotypes of African large barb Labeobarbus intermedius (Osteichthyes: Cyprinidae) in Lake Hawassa,Ethiopia

Water and muscle tissue samples from two morphotypes of the African large barb Labeobarbus intermedius collected from three sites in Lake Hawassa in 2012–2013 were analysed for eight heavy metals, including Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn. Five metals (Cr, Cu, Mn, Ni and Zn) were detected in fish muscle samples, whereas only Cr, Cu and Ni were detected in water samples. Of the five metals detected in the muscle samples, Cu and Zn were present in higher concentrations in the golden morphotype, whereas Cr, Mn and Ni were found in higher concentrations in the silver morphotype. Bioaccumulation factor (BAF) values indicated that Cr, Cu and Ni have a tendency to accumulate in fish muscle in amounts exceeding those in water. In both morphotypes the highest concentrations of Zn and Mn were detected at the Hospital site, whereas the concentrations of Cr, Cu and Ni were highest at the Tikur Wuha site. Chromium, Cu and Ni concentrations recorded in fish muscle at all sampling sites exceeded the safe limits recommended by FAO/WHO and UNESCO, suggesting that water and fish from Lake Hawassa are contaminated with heavy metals originating from factories, a hospital and agricultural activities in proximity to the lake.     

Risk assessment of heavy metal toxicity through contaminated vegetable from sewage water: Implications for populace health

The present investigation was carried out to evaluate the levels of metals and metalloids in okra (Abelmoschus esculentus) irrigated with city wastewater. Soil and vegetable samples from two different sites irrigated with wastewater were wet-digested and analyzed. Arsenic (As) was found higher at both sites and Cr was many-fold lower at both sampling sites. Among all heavy metals, Mn and Zn were abundant. Highest value of coefficient factor was found for Cr and the lowest for Cd. The high transfer value was recorded for Cu at site-I and for Ni at site-II. Copper and Se showed negative and significant correlations between soil and vegetable, whereas Mn, Zn, As, Cd, Cr, and Ni showed positive but non-significant correlations. Pollution load index in this vegetable was found to be higher for Cd and lower for Cu. Health risk index at site-I was in the order of As > Mn > Mo > Pb > Cd > Ni > Zn > Se > Fe > Co > Cr > Cu, whereas the same order was observed at site-II of the sampling locations. Thus, the health risks of metals through ingestion of vegetables were of great concern in the study area.     

Heavy metal contamination and health risk assessment in soil-rice system near Xinqiao mine in Tongling city,Anhui province,China

In this study, paddy soil and rice grain samples were collected from the vicinity around the Xinqiao mine in Tongling, China to test for the presence of heavy metals (Cd, Ni, Cr, Cu, Zn, and Pb) in soil-rice system. Results indicated that the soil samples were primarily contaminated with Cd and Cu and followed with Zn and Pb. In rice grains, Cd, Cu, and Cr concentrations exceeded recommended guidelines. However, the regional distribution of heavy metals in rice grains and soil was inconsistent. The bioaccumulation factor of heavy metals in rice grains decreased in the order of Cd > Zn > Cu > Ni > Cr > Pb. The BAF was significantly positively correlated with TCLP-extractable metals and significantly negatively correlated with soil pH. However, the relationship between soil organic matter and the BAF in rice grains was complex. Health risk assessment through rice intake showed that hazard quotients of Cu and Cd were greater than 1 and could pose a considerable non-cancer health risk to adults and children; meanwhile, Cr, Ni, and Cd could pose an unacceptable cancer risk. The results indicated that the government must take measures to reduce heavy metal contents in paddy soil and rice.