trends of metal accumulation were found among species sampled from the same area (Pastor et al., 1994). As prey consumption is one of the major ways of contaminant uptake (Stewart et al., 1997; De Gieter et al., 2002; Erasmus et al., 2004), it has been assumed that prey contamination is one of the major causes of interspecific variation among fish, with higher trophic level fish accumulating higher levels of metals such as mercury than lower trophic level species (Campbell et al., 2006; Verdouw et al., 2011). Differences in metal concentrations in fish tissue between cultured and wild Diplodus sargus have even been attributed to differences in prey/feed metal concentrations, pointing to the importance of prey as dominant pathway of metal accumulation in these fishspecies (Ferreira et al., 2008). However, several studies (Trudel & Rasmussen, 2006; Burger & Gochfeld, 2011; Teffer et al., 2014) have suggested that prey contamination and trophic differences may not be sufficient to explain such variation. Rather, other factors such as fish size, age (Adams & Onorato, 2005; Verdouw et al., 2011), growth rate, energy expenditure and consumption rates (Trudel & Rasmussen, 2006) or a combination of these may cause interspecific variation of metal concentrations in fish muscle. This seems to be confirmed by the present results as significant interspecific variation is seen between blacktail and hottentot even where the effect of location has been removed as in the overlapping sampling sites (False Bay and Saldanha Bay), allowance has been made for size effect and considering the fact that blacktail and hottentot are of the same trophic nature with similar diets (Coetzee, 1986; Mann & Buxton, 1992; Kerwath & Winker, 2013; Mann & Dunlop, 2013). When regarding fish size effects on metal accumulation we find this to be species specific as Cr was increasingly
The muscle tissue of long tail tuna and mackerel recorded high total mercury concentration of 0.50±0.71µg/g and 0.45±0.56µg/g, respectively . This study was conducted in Selangor, Malaysia. It can be seen that mercury concentration is higher in fishes collected by Hajeb and co-workers  compared to Mok and co-workers  although both studies are on Malaysian shores. The highest mercury concentration was recorded in pomfret with a reading of 0.155±0.009µg/g. Fishes collected from Selangor recorded readings of 0.043±0.003µg/g (catfish), 0.099±0.007µg/g (tilapia), 0.075±0.010µg/g (jade perch) and 0.069±0.007µg/g (seabass) . This showed that although there were similar locations by both studies, the mercury concentrations were still lower in fish samples collected by Hajeb and co-workers . There was a significant difference (p<0.0001) between fishspecies in terms of mercury concentrations . Hence, the differences in mercury concentration could be due to different fish samples as different species have different metabolism and accumulation of heavymetals. It does not necessarily indicate that the site of collection has more contamination. More studies will be required to understand the factors contributing to the high mercury concentration collected.
Over the last few decades, there has been growing interest in determining heavymetals in the marine environment and attention was drawn to the measurement of contamination levels in public food supplies, particularly fish [1–2]. Heavymetals like mercury (Hg) are environmental contaminant of special concern due to a wide distribution in the environment and likely adverse effects for human health [3-4]. In recent decades, the high concentration of Hg in the environment is due to the use of hard coal, brown coal, and also due to un controlled waste combustion . Globally, the major sources of Hg in coastal systems are atmosphere deposition and anthropogenic origin . The increasing level of Hg found in the food chain caused serious health impact. Minamata disease, which appeared among inhabitants of Minamata Bay, Japan, was caused by the
Despite of the presence of several land-based sources of contamination, particularly at El-Mex Bey and El- Maadiya, and their discharges to the sea might constitute a hazard to marine biota and organisms including fish, shellfish as they will eventually end up in food chain  , the obtained results of the three years showed that the increase in concentrations of copper, lead and mercury was very little revealing no accumulation of these metals in the biological material, even in a non-migrant species of long life such as Donax (Figure 2). However, an increase in the concentration of zinc and cadmium in fish tissues was measured from 1993 to 1995. For example, the concentration of zinc during 1995 was almost 3 times higher than that of 1994 and 4 times higher than that of 1993. In case of cadmium, the concentration of 1995 was 2 times higher than that of 1994 and 4 times higher than that of 1993. Shriadah  as well as Shriadah and Emara  found no highly trace metals concentrations in the tissues of different fishspecies that could endanger consumer. Differences in the concentration of most metals, between the different fishspecies and locations examined, except the increase in Pb concentration during summer which could be a result of human impact and traffic increase. Seasonal varia- tions in the concentration of these metals were also relatively little (Figure 3). Moreover, no interspecies differ- ences in the concentration of most heavymetals in fish tissues (Figure 4) coincided with the variations in feed- ing habits and behavior of the different species . Metal contents in tissues of demersal fishes such as Solea- vulgaris, Mugilcephilus were more or less comparable to those measured in tissues of pelagic fish Moron labrox throughout the study period. Habashi et al.  found also no significant differences in some metal concentra- tions, such as lead between species, size or age of fish collected from Western area of the Arabian Gulf. Non- parametric rank order correlation between the concentrations of different trace metals in different tissues was assessed by using the software [Minitab-12]. This indicated that the accumulation of metals by marine organ- isms was affected by several and complicated factors, such as wind, current regime, salinity variation during different months, impact of different pollution sources .
sexual condition, feeding, time of the year and other physiological factors . A few metals are found to be essential due to their beneficial role in the physiological activity of the human beings. Iron, copper, zinc and manganese are essential metals but mercury, lead, cadmium and arsenic are considered as the toxic metals, because of their undesirable effects . These toxic metals are found naturally in the earth. Due to human activities like paints, fertilizers, lead – acid batteries and aging water supply infrastructure metals concentrations become more and affect the human beings through consumption of aquatic organisms. The toxicity of various heavymetals affect the metabolical activity of the various marine organisms [14, 15]. The study was designed to provide information on seasonal variations of proximate composition, concentration of different heavymetals in sea water and different fishspecies available at the southeast coast region of Cuddalore.
It is clear that heavy metal uptake by the marine microalgal isolates tested follows the same general pattern both with different algae and with different metals. Metal uptake was a two phase process with an initial rapid stage followed by a slower second stage. The initial step saturated very rapidly and was effectively complete within two minutes. However, the exact point of saturation is unclear as the two stages of uptake are concurrent rather than sequential (Figure 4.1). The first stage of microalgal metal uptake is thought to rely on simple adsorption by charged groups on the cell wall (Ford & Mitchell, 1992; Gadd, 1988), and as such it occurs independently of metabolism. This metabolism independence has been confirmed in Chlorella emersonii (211 8 b) by the use of 3,3,4-
The study was done for concentration of heavymetals cadmium, cobalt, copper, Iron, manganese, Lead and zinc in some animal products fresh( fish and hens eggs) sample consumed in Merowe city north Sudan. Our results indicated that little variability with brand. Generally, Cd, and Pb concentration in fish exceeded the maximum allowed values stipulated world health organization (WHO) limits (P<0.05). Whereas the levels of Cd and Pb were higher in hens egg. The estimated daily intake values of Cd and Pb through hens eggs were found above the recommended permissible levels. The mean concentration of zinc in tow samples has least recommend dietary allowance given as (12-15mg/day). The WHO limit for zinc 121mg/kg. The elevated level could be related to contamination and pollution of the aquatic environment. The estimated daily intake of Zn was in range of WHO recommended values this indicates that the hen’s egg and fish are not adequate source of essential elemental element Zn. Hen’s eggs found to be the richest in iron, while fresh fish was found to be the poorest. Among the seven metals in tow samples studied, in fresh fish highest concentration of lead, than hens egg. No significant different observed between Cd and Mn in hens eggs. However Co and Cu in fish above than eggs sample. Animal products samples for heavymetals in the study work pose a threat of lead and cadmium toxicity due to their exposure to direct sources of air, water and plants.
CzECH REPUblIC The recommendations are for the most part based on those of EFSA. Women considering pregnancy, pregnant women, breastfeeding mothers and children up to three years of age should not consume shark, swordfish and large predatory freshwater fish, such as pike, pike-perch and asp. Other types of fish, such as white tuna and mack- erel, might also contain elevated levels of mercury. High-risk groups are therefore advised not to consume more than 170 g of these fish (i.e. one portion) per week. The govern- ment also recommends that specific Czech authorities moni- tor the levels of mercury in fish caught locally in rivers and streams. If elevated mercury levels are found, they are advised to recommend that high-risk groups do not consume more than 170 g per week.
Copper is an essential element for good health and seafood is known as a good source of dietary copper, but it is very toxic when consumed excessively (Mol, 2011), and for that reason, a maximum limit intake of Cu was set at 30 mg/day by WHO (WHO, 1996). Therefore, a high intake of Cu has been recognized to cause adverse health problems such as kidney and liver damage for human (Hussein, & Khaled, 2014; Stancheva, Makedonski & Peycheva, 2014). According to the results of the present study, Cu in canned fish samples with an average of 0.92 ± 0.19 µg/g wet weight was much lower than the MPL. The results of other study showed that the mean concentrations of Cu in the muscle of three tuna species from Alexandria, Egypt were 1.25 ± 0.43 µg/g w.wt (Hussein & Khaled, 2014). Also, Ikem & Egiebor (2005) reported that the mean concentrations of Cu (µg/kg w.wt) in canned fish from Georgia and Alabama were 0.32 for pink salmon, 0.47 for red salmon, 0.25 for tuna, 0.81 for mackerel, 0.83 for sardines and 0.60 for herring. Table 3 shows a comparison of metal concentration in the canned fish from Iran with some other regions Table 1. Concentrations and analysis of LOD and LOQ of metals in canned fish samples (µg/g, wet weight)
Heavymetals may enter natural aquatic media from natural and anthropogenic sources including industrial and domestic sewage, storm runoff, leaching from landfills and atmospheric deposits (Dhinamala et al. 2017). The heavy metal rank profile in water was Cu>Cr>Pb>Cd while the same trend was observed for sediment, an indication that the heavy metal content in water was proportionally related to the corresponding heavy metal load in sediment. Clearly, there was an intimate link between the heavy metal profiles of both media. In addition, sediments are repositories for diverse pollutants and are thus capable of feeding the overlying water column with such domiciled pollutants especially under perturbed conditions (Wangboje and Oguzie, 2013). It was observed that the mean concentrations of Cd, Cr and Cu in water were highest at the Egbemeji-Odo station, which was probably influenced by the direct influx of effluents such as palm oil mill effluents. The mean concentrations of Pb in water and sediment were highest at the Odo station, probably due to the boating activities at this station which could introduce fossil fuel into the water. The DC values, which generally express the solubility of metals in water, took the order Cd>Pb>>Cu>Cr. Since Cu had the highest mean concentrations in water and consequently in sediment, the DC value for Cu, would have been dominant but obviously some other factors may have come into play which produced the variation. For example, heavymetals are known to be associated with different fractions in sediment which may have accounted for the variation. These operationally defined fractions include exchangeable metal fraction, carbonate-bound metal fraction, Fe- Mn oxide metal fraction, organic/ sulphide metal fraction and residual metal fraction (Tessier et al. 1979; Lin et al. 2003; Wangboje et al. 2014b). Significant differences (P<0.05) were observed in the mean concentrations of Cr and Cu in water between months, an indication of the effects of seasonal variation on the concentrations of metals in natural aquatic media. On the other hand, there were no significant differences (P >0.05) in the mean concentrations of metals in water between stations, an indication that there was a conceivably steady input of the metals and their associated compounds into the
In evaluating Nautochilus, it m ust be com pared w ith typical Orthosiphon and with Orthosiphon Sect. Serrati M . A shby. T he latter Section consists o f three species, O. serratus Schltr., O. pseudoserratus M . A shby an d O. tubiform is R. G ood, and ap p ears to be restricted to so u th ern Africa. A ch arac ter th a t seems to be o f im p o rtan ce in separating Sect. Serrati from typical Orthosiphon is the place o f attach m en t o f the u p p er p a ir o f stam ens. In typical Orthosiphon, as represented by O. australis V atke, the tw o up p er stam ens are attach ed a b o u t 1-2 m m from the th ro a t and the filam ents are filiform and glabrous. In Sect. Serrati, the tw o u p p er filam ents are a tta ch ed n ear the base o f the corolla tube, while the filam ents are slightly swollen and p u bescent in the low er p a rt. A n o th e r ch aracter w hich m ay have significance is the shape o f the disc. In the few typical species o f Orthosiphon exam ined, the disc is flat except fo r the developm ent o f an a n te rio r lobe equal to the height o f the ovary. In Sect. Serrati, the disc is an n u lar, su rro u n d in g the ovary, a n d reaching to the lower h a lf o r the to p o f the ovary. Nautochilus is sim ilar to Sect. Serrati in b o th these ch aracters.
or roughly oblong to obovate, frequently curved and narrowing slightly above, shortly clawed at the base, longer or shorter than the keel, with a ventro-lateral lobe on each side in E. acanthocarpa. Stamens diadelphous, with the filaments free above and united into a split tube below except the vexillary filament which is free to its base in E. lysistemon but is united to the staminal-tube for varying lengths in the otherspecies ; anthers linear, 2-thecous, dehiscing by longitudinal slits, dorsi-fixed. Ovary linear, many- ovuled, densely tomentose, on a gvnophore ; style linear, hispid below, glabrous above, rarely glabrous along its whole length ; stigma small, simple, terminal. Pcds (in those species seen) dark, subligneous, stalked, falcate, armed with prickles only in E. acanthocarpa constricted between the seeds and with these constrictions frequently elongated. Seed red, elliptic, with a scar o f attachment.
Concentrations of total fishmercury were obtained from the SC DHEC Bureau of Water for 1995–2005 . The SC fish biomonitoring program follows a standard- ized protocol that includes quantification of fish total mer- cury concentrations by cold vapor atomic absorption spectrometry (EPA method 245.6; a program description is provided in ). Fish sampling targeted large public water bodies throughout SC; sampling criteria included consideration of public access, fishing opportunities, and successful catches. Smaller rivers and streams and private lakes were not sampled due to resource constraints. Largemouth bass data were used in the analysis as repre- sentative fish that are caught for consumption (N = 3,828 samples). Mercury levels in largemouth bass rank among the highest relative to otherfish in SC, and they compare reasonably well with some but not all other commonly consumed species . They are ubiquitous in SC fresh- water and were well represented in the SC DHEC Bureau of Water database. Using spatial coordinates for fish sam- ple locations, a geostatistical model (spatial interpolation via ordinary kriging) within a GIS (ArcGIS, Redlands, CA) was used to map the predicted statewide distribution of total mercury concentrations in fish (Figure 1). Kriging provides a statistically unbiased method for predicting unknown values from observed data at specific geographic locations . Several parameters were evaluated to ob- tain the best fitting model of fish total mercury concen- trations, including trend analysis, semivariogram model goodness-of-fit, and variations in the searching neigh- borhood. Trend analysis identified a U-shaped trend that was modeled with a second-order polynomial. The semivariogram was fitted with a mathematical model for use as an interpolator; spherical and exponential models were evaluated, and the Q-Q plot for the exponential model provided a better fit. Anisotropy from northwest to southeast, following the flow of water in SC, was used due to impacts on the semivariogram and the resulting fitted model. The searching neighborhood used to en- close measured points and predict values was defined with a directional ellipse with four sectors. The Geosta- tistical Wizard function in ArcGIS was used to evaluate how the shape and number of sectors affected the pre- dicted value, as well as evaluate which neighbors were
rinsed with deionized water and dried in the oven. Ap- proximately 0.2 g of sediment and fish samples were weighed into the Teflon vessels avoiding contact with the sides of the vessels. Using a pipette, 2.5 ml concentrated nitric acid was added slowly to each sample in the Teflon vessels. Blanks were prepared in a similar fashion along- side the sediment and fish samples. The Teflon vessels contained only 2.5 ml of concentrated nitric acid. The laboratory used IAEA 356 as certified reference material for sediment. IAEA 350 was used as the certified refer- ence material for fish samples. Five samples with one sediment standard and one fish standard were digested for analysis with two blanks at a time. The vessels were closed and placed in stainless steel bombs. The block of bombs were placed on a hot plate and heated under pres- sure at 150 o C for seven hrs. The samples were allowed to cool to room temperature after which the pressure was carefully released and the bombs opened. The samples were transferred into labeled 50 ml polypropylene tubes. The Teflon was rinsed three times with deionized water. The water from the rinsing was subsequently added to the polypropylene tubes. The content of each tube was diluted to the 25 ml mark with deionized water and mixed thoroughly. The tubes were closed and left to stand overnight to allow the particles to settle.
Studies with single metal exposure have demonstrated that As, Cd, or Pb inﬁltrate the immature blood-brain barrier (BBB) and accumulate in developing brain . Pb uptake through the BBB disrupts Ca2þ transport mechanism  and promotes activation of mitogen-activated protein (MAP) kinases in apoptotic glial cells . The sequestration of Pb at the level of the choroid plexus undermines brain growth and affects learning and cognitive functions of CNS , especially in children. Combination of 1-month pre-exposure of HgC l2 before MI changed the endothelial generation of oxidative stress induced by mercury exposure from NADPH oxidase pathway to XO (xanthine oxidase)-dependent ROS production . It has been suggested that reactive oxygen intermediates (ROIs) may have a role in the genotoxic effects of lead (Pb 2+ ) and mercury (Hg 2+ ).
Mining, manufacturing, and the use of synthetic products, e. g., pesticides, paints, batteries, industrial waste, and land application of industrial or domestic sludge, can generated heavy metal contamination for urban and agricultural soils. Heavymetals also occur naturally, but rarely at toxic levels. Potentially contaminated soils may occur at old landfill sites (particularly those that accepted industrial wastes), old orchards that used insecticides containing arsenic as an active ingredient, fields that had past applications of waste water or municipal sludge ,areas in or around mining waste piles and tailings, industrial areas where chemicals may have been dumped on the ground, or in areas downwind from industrial sites . When using the contaminated soil to produce food by various crop plants, as the easy entry of these elements in the food chain, which increases the risk to human health .
The concentrations of heavymetals, Cd, Hg, Pb, Cu and As in marine sediments from 138 sites lo- cated in the Beidaihe near-shore area of Bohai bay, were analyzed to find out the distribution characteristics of these heavymetals. Potential Ecological Risk index were adopted to assess the heavymetals contamination, and the assessment results indicated that the content of heavy met- als in this area is in a low to moderate level, while high values were found in the southwest and northeast region, and the value in the middle region is comparatively low. The high pollution ha- zard sites were close to the Renzaohe estuary and Shihe estuary and the high risk is mainly led by Hg.