Cadmium In Tissues Research Articles

Cadmium bioaccumulation and elimination in tissues of the freshwater mussel Anodonta woodiana

Experiments were carried out to investigate the bioaccumulation and elimination of cadmium (Cd) in tissues (kidney, gills, digestive gland, mantle, visceral mass, foot, adductor muscle and hemolymph) from the freshwater mussel, Anodonta woodiana. The mussels were exposed to subchronic Cd at concentrations of 0.168 and 0.675 mg L−1 for 28 d of bioaccumulation and 28 d of elimination. During the bioaccumulation phase, Cd bioaccumulations increased in all tissues. The highest bioaccumulation of Cd was found in the kidney. The second-highest and third-highest bioaccumulations of Cd were found in the digestive gland and gills, respectively. The Cd bioaccumulations in the tissues of A. woodiana increased with exposure time and concentration, except for hemolymph, which reached the highest value on d 14. The bioaccumulation factors (BCFs) increased with exposure time, but an inverse relationship was observed between BCFs and exposure concentration. During the elimination phase, the visceral mass showed the highest Cd elimination rate. In the kidney, digestive gland and gills, the elimination rates almost reached 40%, but their concentrations were still higher than in other tissues. Thus, we concluded that the kidney, gills and digestive gland of A. woodiana are target tissues for subchronic Cd toxicity.

Examination of metal mobilization from a gunshot by scanning acoustic microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and inductively coupled plasma optical emission spectroscopy: a case report

BackgroundProjectile foreign bodies are known to cause chronic heavy metal toxicity due to the release of metal into the bloodstream. However, the local effect around the metallic object has not been investigated and the main goal of our study is to examine the influence of the object in close proximity of the object.Case presentationA 36-year-old Caucasian woman with one metallic pellet close to her sciatic nerve due to a previous shotgun injury at the gluteal area presented with a diagnosis of recurrent lumbar disk herniation at L4–5 level. A physical examination confirmed chronic neuropathy and she underwent a two-stage surgery. The surgery included removal of the foreign body, followed by discectomy and fusion at the involved level. During the removal of the metallic foreign body, a tissue sample around the pellet and another tissue sample from a remote area were obtained. The samples were analyzed by scanning acoustic microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Lead, chromium, copper, cadmium, iron, manganese, selenium, and zinc elements in tissue, blood, and serum specimens were detected by inductively coupled plasma optical emission spectroscopy.ConclusionsAn acoustic impedance map of the tissue closer to the metallic body showed higher values indicating further accumulation of elements. Energy-dispersive X-ray spectroscopy results confirmed scanning acoustic microscopy results by measuring a higher concentration of elements closer to the metallic body. Scanning electron microscopy images showed that original structure was not disturbed far away; however, deformation of the structure existed in the tissue closer to the foreign body. Element analysis showed that element levels within blood and serum were more or less within acceptable ranges; on the other hand, element levels within the tissues showed pronounced differences indicating primarily lead intoxication in the proximity of the metallic body. We can state that residues of metallic foreign bodies of gunshot injuries cause chronic metal infiltration to the surrounding tissue and induce significant damage to nearby neural elements; this is supported by the results of scanning acoustic microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and inductively coupled plasma optical emission spectroscopy.

Simultaneous mitigation of tissue cadmium and lead accumulation in rice via sulfate-reducing bacterium

The objectives of this study were to investigate the mechanism responsible for Cd and Pb immobilization by sulfate reduction to sulfide and effectiveness of decreasing Cd2+ and Pb2+ bioavailability in culture solution and paddy soils via sulfate-reducing bacterium (SRB1-1). The SRB1-1 strain, exhibiting high resistances to Cd2+ and Pb2+, was isolated from bulk soils in the metal(loid)-contaminated paddy field. During the culture of the SRB1-1 strain, the removal percentages of Cd2+ and Pb2+ from culture solution reached 99.5% and 76.0% in 72 h, respectively. The surface morphology and composition of metal precipitates formed by SRB1-1 strain were analyzed by transmission electron microscopy (TEM) and further confirmed to be CdS and PbS by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). When living SRB1-1 strain was applied in Cd and Pb-contaminated soils, the SRB1-1 strain could stably colonize using its resistance to rifampicin, and showed significantly impact on the bacterial community composition. Cd and Pb contents in rice grains were decreased by 29.5% and 26.2%, respectively, while Cd and Pb contents in the roots, culms, leaves, and husk were also decreased ranging from 19.1% to 43%, respectively. Due to growth in highly Cd and Pb contaminated soils, Cd content of the rice grains did not meet the standard for limit of Cd and Pb, but safe production of rice plants may be obtained in slightly or moderately metal(loid)-contaminated soils in the presence of the living SRB1-1 strain. These results indicated that the SRB1-1 strain could effectively reduce the Cd and Pb bioavailability in soils and uptake in rice plants. Our results highlighted the possibility to develop a new bacterial-assisted technique for reduced metal accumulation in rice grains, and also showed potential for effective synergistic bioremediation of SRB1-1 strain and rice plants in metal(loid)-contaminated soils.

Are Grapes Able to Mitigate the Noxious Effects Induced by Cadmium Exposure in Different Tissues and/or Organs? A Mini Review.

Grapes are fruits that grow in clusters and can be crimson, black, dark blue, yellow, green, orange, and pink. Cadmium is a non-essential metal toxic to living organisms and the environment. Recently, health professionals, food scientists, and consumers have paid much attention to grapes for their health-promoting effects. To the best of our knowledge, there are no reviews describing the ability of grapes to mitigate the toxic effects induced by cadmium exposure in different tissues and/or organs. Herein, the aim of this review is to present the effects of grapes following cadmium exposure on the number of papers published in the scientific literature. The results showed that grapes are able to mitigate the harmful activities induced by exposure to cadmium in several tissues and organs. The main actions are closely related to tissue regeneration as a result of the reestablishment of morphology and antioxidant activity. However, further studies are welcomed in order to elucidate new biological pathways regarding the outcomes promoted by grapes in this context, specially related to inflammation, tissue regeneration and cellular death.

Zinc, copper, cadmium, and lead levels in cattle tissues in relation to different metal levels in ground water and soil.

The objective of the present study was to investigate the interaction between environmental (water and soil) levels of zinc, copper, cadmium, and lead levels, as well as their content in Hereford beef cattle tissues in five districts (D1-western area, D2 and D3-central area, D4 and D5-eastern area) of the Orenburg region. Soil metal levels were assessed using atomic emission spectrometry, whereas water and tissue (liver, kidney, muscle, heart) metal content was studied using inductively coupled plasma-mass spectrometry. The obtained data demonstrate that the highest levels Zn in soil and water (p < 0.001), as well as cattle muscle, liver, and kidney (p < 0.05) were observed in D4 and D5 (eastern area), exceeding the maximum permissible concentration levels (MPCL) for drinking water and muscle for all regions. Similar associations were found for Cu levels. The highest soil and water Cd and Pb content were observed in D2 (central area) and D5 (eastern area), respectively. At the same time, cattle tissue Cd and Pb content did not correspond to the respective environmental levels. Correlation analysis demonstrated that water and soil Zn and Cu content directly correlated with muscle, liver, and kidney, but not heart metal content. At the same time, water Cd levels were negatively interrelated with muscle cadmium content but correlated directly with hepatic metal content. Both water and soil Pb levels positively correlated with renal metal levels in cattle. In turn, soil lead content was inversely associated with muscle metal levels. Regression analysis also demonstrated a significant association between environmental and tissue levels of Zn and Cu. The models adjusted for all studied elements demonstrated a significant effect of metal interaction on tissue metal levels. Hypothetically, excessive environmental Zn, and possibly Cu, levels may affect the uptake of heavy metals including Cd and Pb from the environment.

TOXIC METAL RESIDUES IN NON-EDIBLE ANIMAL BYPRODUCTS

Environmental pollution by heavy metals is a major problem worldwide. Domesticated animals such as cattle and camel share the same environmental conditions like human and they are exposed to heavy metals via different sources. Therefore, these animals are considered as ideal bio-indicators for human exposure to heavy metals. Heavy metals accumulate in the different tissues of the animals. Estimation of toxic metal residues such as arsenic (As), mercury (Hg), lead (Pb) and cadmium (Cd) in the animal edible tissues had been extensively studied. However, estimation of such toxicants in the non-edible animal byproducts had received little attention. Additionally, non-edible animal byproducts are frequently used in many industries such as animal feed additives and leather fabrication. Therefore, this study was undertaken to estimate the residual concentrations of As, Hg, Pb and Cd in the hair, hides and bones of cattle and camel slaughtered at Zagazig, Abo-Hammad and Belbies cities, Sharkia Governorate, Egypt. Metal-metal correlations were additionally calculated. The achieved results indicated exposure of cattle and camel to high levels of heavy metals, particularly lead and arsenic. Camel had higher concentrations (mg/kg ww) of arsenic compared with cattle particularly in hair (38.57 ± 8.77 and 22.48 ± 1.91 in camel and cattle, respectively). Bone had the highest load of the measured metals among examined samples. For instances, in camel, elemental concentrations (mg/kg ww) in bone were 34.53 ± 6.16 (As), 3.41 ± 0.56 (Hg), 2.76 ± 0.36 (Pb) and 0.11 ± 0.01 (Cd). Samples collected from Zagazig city were highly contaminated compared with other locations. Significant positive correlations were observed between lead - mercury, lead - cadmium and arsenic- mercury (r &lt;0.0001 in each). Contaminated non-edible animal byproducts should be hygienically disposed and avoid its introduction to downstream industries. It is highly recommended to control environmental pollution with heavy metals in Egypt.

Lead and Cadmium Levels in Mussels and Fishes from Three Coastal Ecosystems of NW Mexico and Its Potential Risk due to Fish and Seafood Consumption

The aim of this study was to evaluate the levels of cadmium and lead in edible tissue of Mytella charruana and Mugil curema from three coastal lagoons (Altata Ensenada del Pabellon, AEP; Urias, URI; and Teacapan, TEA) of Sinaloa (NW of Mexico) during an annual cycle, to compare maximum permissible levels (MPLs) of with legal limits of cadmium and lead, and to assess potential risk for consumers. Samples of charry mussel (M. charruana) and white mullet (M. curema) were collected every two months between July 2005 and July 2006 in three of the main lagoon systems in the state of Sinaloa (NW Mexico): Altata-Ensenada del Pabellon (AEP), Urias (URI) and Teacapan (TEA), which represent different pollution. The range of mean levels in the studied lagoons were as follows: in M. charruana Cd 0.064 to 0.222 and Pb 0.206 to 0.482 μg g-1 ww, respectively and in M. curema Cd 0.003 to 0.018 and Pb 0.013 to 0.019 μg g-1 ww, respectively. Taking into account national and international regulations, the Cd and Pb levels detected in M. curema apparently do not pose a risk for human health. Nonetheless, for M. charruana the scenario is different, some levels of Cd in TEA surpassed maximum permissible levels (MPL’s) of European Commission (EC) and Codex regulations and on the other hand, Pb levels in AEP rather than URI surpassed MPLs of national and international regulations. Although some levels exceed legal limits, risks for human health are diluted because EDI - of Cd and Pb - via consumption of edible tissue of fish were far below the provisional permissible tolerable daily intake (PTDI) values established by FAO/WHO. However, this situation is different if we taking into account, different patterns of consumption in mussels, few EDI values exceed the established levels of PTDI.

Ralstonia eutropha Q2-8 reduces wheat plant above-ground tissue cadmium and arsenic uptake and increases the expression of the plant root cell wall organization and biosynthesis-related proteins

In this study, the molecular mechanisms involved in Ralstonia eutropha Q2-8-induced increased biomass and reduced cadmium (Cd) and arsenic (As) uptake in wheat plants (Triticum aestivum cv. Yangmai 16) were investigated in growth chambers. Strain Q2-8 significantly increased plant biomass (22–75%) without and with Cd (5 μM) + As (10 μM) stress and reduced plant above-ground tissue Cd (37%) and As (34%) contents compared to those in the controls. Strain Q2-8 significantly increased the proportions of Cd and As in wheat root cell walls. Under Cd and As stress, 109 root proteins were differentially expressed among which those involved in metabolisms, stress and defence, and energy were dominant in the presence of strain Q2-8. Furthermore, energy-, defence-, and cell wall biosynthesis-related proteins were found to be up-regulated. Notably, differentially expressed cell wall biosynthesis-related proteins in roots were only found in bacteria-inoculated plants under Cd and As stress. The results suggest that strain Q2-8 can alleviate Cd and As toxicity to wheat plant seedlings and reduce above-ground tissue Cd and As uptake by increasing the efficiency of root energy metabolism, defence, and cell wall biosynthesis under Cd and As stress.

The effect of vehicle exhaust emissions on morphometric and physiological characteristics of Rhus typhina

Rhus typhina L. (Staghorn Sumac) is fast-growing woody species that reproduces by rhizomes and seeds. Because of its biological benefits, this deciduous member of the Anacardiaceae family has been introduced from its native habitats in the east of North America to urbanized landscapes of Ukraine. In this study we anаlyse changes in morphometric and physiological indicators of 12-year plants of this species in artificial phytocenoses near highways in Pavlograd, Ukraine. Experimental plots were placed at a distance from 25 to 130 meters from the road. The control group of plants was at a distance of 1500 m from the highways. We measured the length and thickness of the annual sprout, number of leaves on it, the content of chlorophyll in the leaves and accumulation of cadmium and lead in the leaf tissues. It was found that, compared to the plants in the relatively clean area, the greatest decreases in the length of the annual shoots of the trees in the plantations were for those which were at a distance of twenty five metres and forty meters from the traffic lanes of the highways. The thickness of the annual shoots of the trees in the plantations did not differ from plants in the clean zone. The number of leaves on a one-year annual sprout at a distance of twenty five meters and forty meters from the path of moving sources of pollution was significantly lower compared to control. We evaluated the impact of vehicle exhaust emissions on the assimilatory organs. We identified a negative effect of the anthropogenic pollutants on photosynthetic pigment content in leaves. The amount of chlorophyll a and chlorophyll b decreased with decreasing distance from the plantation to the road. Changes in the content of chlorophyll b had a clear pattern. The concentration of this pigment and the amount of chlorophyll a + b decreased compared with control in the 130 meter area. The amount of toxic heavy metals (lead and cadmium) in the tissues of the leaf was significantly higher than the control values on all plots. The strongest negative effects of phytotoxicants on susceptible plants occurred in plantations in the twenty-five-meter zone, which led to deterioration of the decorative quality of the plants.

Concentrations of selected heavy metals in placental tissues and risk for neonatal orofacial clefts

Orofacial clefts (OFCs) have multifactorial etiologies. Prenatal exposure to heavy metals can induce OFCs in animal models, but evidence from studies of human subjects is scarce. We examined whether concentrations of mercury (Hg), cadmium (Cd), lead (Pb), and arsenic (As) in placental tissues are associated with risk for OFCs in offspring. This population-based case-control study included 103 newborns affected by OFCs with available placental tissues and 206 controls randomly selected from 509 non-malformed newborns with available placenta samples, recruited in five rural counties in northern China. Sociodemographic information was collected using a structured questionnaire in face-to-face interviews. The concentrations of Hg, Cd, Pb, and As in placental tissues were analyzed using an inductively coupled plasma-mass spectrometry in helium mode. The median concentrations of Hg (7.4 ng/g), Cd (57.1 ng/g), and Pb (96.1 ng/g) were all statistically significantly higher in OFC cases than in controls (Hg 5.5 ng/g, Cd 38.6 ng/g, and Pb 67.9 ng/g, respectively); no differences were observed between the two groups in median concentrations of As. Concentrations above the median for all subjects were associated with a 2.33-fold (95% confidence interval [CI] 1.33–2.09) increased OFC risk for Cd and a 3.08-fold (95% CI 1.74–5.47) increased risk for Pb. The risk for OFCs increased with concentration tertiles, with an adjusted odds ratio of 3.06 (95% CI 1.36–6.88) for the second tertile and 8.18 (95% CI 6.64–18.37) for the highest tertile of Cd, and 3.88 (95% CI 1.78–8.42) for the second tertile and 5.17 (95% CI 2.37–11.29) for the highest tertile of Pb. The association between Hg concentration and OFC risk was borderline nonsignificant after adjusting for confounding factors. Prenatal exposure to Cd and Pb, as reflected by their concentrations in placental tissues, is associated with an increased risk for neonatal OFCs.

Silicon nutrition lowers cadmium content of wheat cultivars by regulating transpiration rate and activity of antioxidant enzymes

Given that cadmium (Cd) uptake by plants is linked to transpiration rate and activity of antioxidant enzymes and further that silicon (Si) can regulate them, it was hypothesized that improved Si nutrition could reduce Cd concentration in plants. Thus, present study was carried out to elucidate the positive effect of Si nutrition on the growth, activities of antioxidant enzymes and tissue cadmium (Cd) concentration in Cd-tolerant (Iqbal-2000) and Cd-sensitive wheat (Triticum aestivum L.) cultivars. Fifteen days after seedling transplantation, 15 μM Cd stress alone and in combination with 0.6 mM Si was applied. Silicon application improved root and shoot dry matter of Cd-sensitive cultivar Sehar-2006 while the effect was non-significant in Cd-tolerant cultivar Iqbal-2000. Silicon-treated Cd-sensitive cultivar showed marked improvements in chlorophyll content and photosynthesis, while stomatal conductance and transpiration rate decreased by Si application. Silicon treatment enhanced the activities of enzymatic antioxidants including catalase, ascorbate peroxidase, guaiacol peroxidase and superoxide dismutase and the increase was higher for Cd-tolerant cultivar Iqbal-2000. Although Si nutrition depressed malondialdehyde (MDA) content in both Cd-stressed cultivars, the response was more evident in Cd-sensitive Sehar-2006. Lower lipid peroxidation was related to Si-induced increase in antioxidant activities only in Cd-sensitive cultivar. Silicon application decreased Cd accumulation in the roots and shoots of both the cultivars. The decrease in shoot Cd was associated with a decrease in Cd uptake by roots and Cd translocation from roots to shoots. Overall, it is concluded that Si suppressed Cd contents by decreasing transpiration rate in Cd-sensitive cultivar and by increasing antioxidant activity in Cd-tolerant cultivar.

Cadmium concentration in terminal tissues as tools to select low-cadmium wheat

The consumption of cadmium-contaminated food adversely affects human health. Heritable variation for the propensity to accumulate cadmium in the grain exists, but is a difficult selection target, given the practical limitations of breeding operations. The main objective of this study is to assess the feasibility and accuracy of selecting low-cadmium lines during grain filling using cadmium concentration in terminal tissues. Cadmium and other mineral concentrations in terminal tissues of two low- and high-cadmium winter wheat cultivars (Triticum aestivum L.) were measured at 2, 3, 4, and 5 weeks after average anthesis (WAAA) and at maturity in two years. Cadmium concentration in grain at 3 and 4 WAAA, in rachis at 2, 4 and 5 WAAA, and in the terminal vegetative node at 3 and 4 WAAA separated high- and low-cadmium cultivars. Controlling disease with fungicides did not affect the ability to select low-cadmium cultivars. Across environments, low-cadmium cultivars had lower concentration of cadmium, but similar concentration of iron and zinc in developing and mature grains, compared to the high-cadmium cultivars. Low-cadmium lines can be selected before harvest using Cd concentration in terminal tissues. It is possible to select low-cadmium lines that are consistently low across environments.

Effect of salinity on the bioaccumulation and depuration of cadmium in the pacific cupped oyster, Crassostrea gigas

As a euryhaline species, the oyster Crassostrea gigas can adapt rapid and dramatic salinity fluctuations, and show physiological mechanisms of adaption to tolerant salinity changes. They are continuously exposed to Cd because they are filter feeders and their mobility is poor. In order to understand the influence of salinity on the molecular responses of C. gigas exposed to Cd, oysters were acclimatized to different salinities (13, 20, 27, and 34) for 14 days and then exposed to 10 μg/L Cd for 28 d, followed by a depuration period of 35 d. Control groups were kept at the same salinities without Cd. Oysters were sampled for chemical analysis by inductively coupled plasma mass spectrometry (ICP-MS) and for mRNA quantification by qPCR. The rank order of the mean concentrations of Cd in oyster tissues was digestive gland > mantle > adductor muscle. Use of a two-compartment model showed that in the three tissues, Cd uptake rates (k1) in digestive gland (13.525–35.430 d−1) also increased as salinity decreased. However, no difference was observed in Cd uptake rates of C.gigas in the three higher salinities in mantle (11.703–17.250 d−1). Cd depuration rates (k2) (0.0139 - 0.0127 d-1 in mantle and 0.0111-0.0134 d−1 in digestive gland) followed a reverse trend. There was not a relationship between k2 and salinity in adductor muscle. In response to Cd contamination, MT was significantly up-regulated by Cd at all salinities, and P-gp was significantly up-regulated in mantle, while down-regulated in digestive gland, which means a disruption of the protein synthesis at high concentration. At depuration phase, MT level was higher in digestive gland and mantle, and its expression was higher at S13 than that at S34. No relationship was found between the P-gp gene expression level and concentrations of cadmium in tissues in either accumulation phase or depuration phase. In accumulation phase, the MT gene expression level was positively correlated with the concentration of cadmium in both the digestive gland and the mantle, while the relationship was weakened in depuration phase, suggesting an effort to create a detoxification mechanism.

Protective Effect of Ganoderma Triterpenoids on Cadmium-Induced Testicular Toxicity in Chickens.

Studies have shown that cadmium can cause chicken testicular damage, but a protective effect of Ganoderma triterpenoids on cadmium-induced testicular damage in chickens has not yet been reported. The present study was designed to research the protective effect of Ganoderma triterpenoids on cadmium-induced testicular damage in chicken. Eighty healthy 7-day-old Hyline egg laying chickens were randomly divided into four groups with 20 in each group. The control group was fed with normal full-fodder, the model group was fed with normal full-fodder with 140mg/kg of CdCl2, the Ganoderma triterpenoid treatment group was fed with a full-fodder diet containing 140mg/kg of CdCl2 and 0.5mL of Ganoderma triterpenoid solution (20mg/mL), and the Ganoderma triterpenoid group was fed normal full-fodder and 0.5mL of Ganoderma triterpenoid solution (20mg/mL) gavage. The chickens were euthanized at 20, 40, and 60days, respectively, and the testes were harvested. The changes of cadmium contents, the antioxidant enzymes (superoxide dismutase (SOD), glutathione peroxidase (GSH-Px)), peroxide (malondialdehyde (MDA)), inflammatory factors (interleukin (IL)-1β, IL-6, and tumor necrosis factor alpha (TNF-α)), and apoptosis-related proteins (Bax, Bcl-2, and Caspase-3) were detected. The pathological sections of the testes were made at the same time. The results suggested that Ganoderma triterpenoids could reduce the accumulation of cadmium in testis tissue; reduce the content of IL-1β, IL-6, and TNF-α in cadmium poisoning testis; significantly increase the activity of SOD and GSH-Px; decrease the content of MDA; regulate the expression of Bax, Caspase-3, and Bcl-2; and reduce the damage of testicular tissue. The results showed that Ganoderma triterpenoids have a protective effect on cadmium-induced testicular injury in chicken.

Association between cadmium and androgen receptor protein expression differs in prostate tumors of African American and European American men

Cadmium is a known carcinogen that has been implicated in prostate cancer, but how it affects prostate carcinogenesis in humans remains unclear. Evidence from basic science suggests that cadmium can bind to the androgen receptor causing endocrine disruption. The androgen receptor is required for normal prostate development and is the key driver of prostate cancer progression. In this study, we examined the association between cadmium content and androgen receptor protein expression in prostate cancer tissue of African American (N = 22) and European American (N = 30) men. Although neither overall tumor cadmium content (log transformed) nor androgen receptor protein expression level differed by race, we observed a race-cadmium interaction with regard to androgen receptor expression (P = 0.003) even after accounting for age at prostatectomy, smoking history, and Gleason score. African American men had a significant positive correlation between tumor tissue cadmium content and androgen receptor expression (Pearson correlation = 0.52, P = 0.013), while European Americans showed a non-significant negative correlation between the two (Pearson correlation = −0.19, P = 0.31). These results were unchanged after further accounting for tissue zinc content or dietary zinc or selenium intake. African American cases with high-cadmium content (>median) in tumor tissue had more than double the androgen receptor expression (0.021 vs. 0.008, P = 0.014) of African American men with low-cadmium level. No difference in androgen receptor expression was observed in European Americans by cadmium level (high 0.015 vs. low 0.011, P = 0.30). Larger studies are needed to confirm these results and if upheld, determine the biologic mechanism by which cadmium increases androgen receptor protein expression in a race-dependent manner. Our results suggest that cadmium may play a role in race disparities observed in prostate cancer.

Effects of cadmium concentrations on bioaccumulation and depuration in the marine bivalve Donax trunculus

Metal pollution is one of the most dangerous forms of anthropogenic pollution in the Gulf of Annaba. We examine the bioaccumulation of cadmium in the soft tissue of Donax trunculus L. (Mollusca, Bivalvia) under laboratory conditions during exposure and recovery periods. Cadmium was added in seawater at two concentrations corresponding to 96-h LC50 and 96-LC25 previously determined against D. trunculus at different exposure times (48 and 96 h). Our results show a significant increase (p < 0.001) in the concentration of cadmium as compared with controls during the exposure period. The observed effects varied as function the exposure time and the concentration. In a second series of experiments, exposed animals were thereafter transferred to clean water to assess the recovery pattern. The data obtained suggested that Cd was gradually incorporated into the body of D. trunculus.

Classification of trace elements in tissues from organic and conventional French pig production

This study assesses the impact of the farming system on the levels of copper, zinc, arsenic, cadmium, lead and mercury in pig tissues from three types of production (Organic (n = 28), Label Rouge (n = 12) and Conventional (n = 30)) randomly sampled in different slaughterhouses. All the concentrations were below regulatory limits. In muscles, Cu, Zn and As were measured at slightly higher levels in organic samples but no differences between organic and Label Rouge was observed. Livers from conventional and Label Rouge pig farms exhibited higher Zn and Cd contents than the organic ones, probably due to different practice in zinc or phytase supplementation of fattening diets. Principal component analysis indicated a correlation between Cu and As concentrations in liver and carcass weight, and between Zn and Cd liver levels and lean meat percentage. The linear discriminant analysis succeeded in predicting the farming process on the basis of the lean meat percentage and the liver Cd level.

SEASONAL LEVELS OF HEAVY METALS IN SOFT TISSUE AND MUSCLE OF THE PEN SHELL Atrina maura (SOWERBY, 1835) (BIVALVIA: PINNIDAE) FROM A FARM IN THE SOUTHEASTERN COAST OF THE GULF OF CALIFORNIA, MEXICO

The pen shell ( Atrina maura ) is a filter-feeder bivalve that may accumulate metals in its body. The objective of this study was to determine seasonal concentrations of copper (Cu), chromium (Cr), cadmium (Cd), nickel (Ni), lead (Pb), arsenic (As), zinc (Zn), and mercury (Hg) in soft tissue and muscle of A. maura cultivated in a farm located in the southeastern coast of the Gulf of California from summer 2011 to summer 2012. Except for Cu, the higher metal concentrations were found during the dry season (winter 2011-spring 2012). The mean values in soft tissue fluctuated from 0.064 ± 0.01 µg/g (dry weight [dw]) for Hg to 485.66 ± 71.12 µg/g (dw) for Zn, while for muscle they varied from 0.058 ± 0.03 µg/g (dw) for Hg to 64.83 ± 4.90 µg/g (dw) for Zn. Concentrations of cadmium (18.15 µg/g in soft tissue and 1.82 µg/g in muscle, wet weight [ww]) and lead (2.31 µg/g in soft tissue, ww) exceeded the permissible limits (36.3, 3.64, and 2.31 times, respectively) recommended by the sanitary regulations of the official mexican standards. The results suggest that variation of metal levels in cultivated pen shell could be influenced by seasonality and anthropogenic activities such as agriculture and aquaculture developed around the culture zone. Continual monitoring of metals in farmed pen shell is recommended.

Distribution of Cadmium in Seawater, Sediment and Soft Tissue of Bivalve in Van Don Coastal in Quang Ninh, Vietnam

Distribution of Cadmium in Seawater, Sediment and Soft Tissue of Bivalve in Van Don Coastal in Quang Ninh, Vietnam

Concentration of Arsenic and Heavy Metals in Snail Tissues

The aim of this study was to determine arsenic and heavy metal concentrations (lead, mercury, copper, cadmium, zinc, iron and manganese) in snail tissues (foot and digestive gland) obtained from snail farms in Serbia (near urban areas). Snail samples were analysed using atomic absorption spectrophotometry. A total of 730 individual snail samples were included in this study. Snails were packed into plastic bags and transported to the laboratory at the Faculty of Veterinary Medicine, University of Belgrade. The levels of arsenic and mercury in the examined snail tissues were below the detection limit of the analytical method. Concentrations of heavy metals were higher in digestive gland tissues than in foot tissues.