Levels of cadmium and lead in tissues of freshwater fish (Clarias batrachus L.) and chicken in Western UP (India)

Metallic trace element dynamics in Paracentrotus lividus from Algeria: Environmental large-scale survey and human health risk assessment

This paper evaluates the dynamics of Metallic Trace Elements (MTEs; Cd, Pb, Fe, Cu, Zn, Ni and Co) in the gonads of the sea urchin Paracentrotus lividus collected in five sites: four contaminated and one reference, along the Western coast of Algeria, recontextualizes this contamination within a wider geographical distribution area throughout 83 sites among the Mediterranean Sea and Atlantic and focuses on the potential risk of their consumption on human health for the first time in Algeria. The trace element pollution index places Algeria, and generally the North African coasts, as the region most contaminated by MTEs. The geographical variability in metal contamination levels is greater in the Mediterranean Sea than in the Atlantic. The health risk assessment indicates that Pb exceeds the maximum limit set by the Commission Regulation (EC) No 1881/2006 at two of the four Algerian contaminated sites.

Cadmium induced bioaccumulation, histopathology, gene regulation in fish and its amelioration - A review

Different anthropogenic activities as well as natural sources contribute enormously towards various heavy metal contaminations in aquatic habitats. Cadmium (Cd) is one of most prevalent and toxic heavy metals with a long half life. Unlike terrestrial animals, exposure of Cd in fishes may happen not only through feeds but also from its habitat water. Bioaccumulation of Cd in fishes occurs in many tissues, but mainly in gill, liver, kidney, skin, and muscle. The concentrations of Cd in fish tissues depend upon the extent and duration of Cd exposure, species and age of fishes, dietary minerals and antioxidant concentrations, and habitat water quality. Specific histopathological observations in liver, kidney, and gill are useful to understand the effects of Cd, which could help to determine the ameliorating methods to be adopted. Exposure of Cd exerts several adverse effects on general growth and development, reproductive processes, osmoregulation, morphological and histological structures, stress tolerance, and endocrine system, mainly due to changes in biological functions induced by differential expressions of several genes related to oxidative stress, apoptosis, inflammation, immunosuppressions, genotoxicity, Cd chelation and carbohydrate metabolism. Chronic biomagnifications of Cd exceeding the permitted level may be harmful not only to the fishes itself but also to humans through food chains. Amelioration of such toxic heavy metal that has been categorized as a potent carcinogenic in humans is of utmost importance. Main modes of amelioration encompas reducing oxidative damages by promoting the antioxidative defenses, decreasing Cd absorption, increasing excretion through excretory system and improving the tolerance of fishes to Cd toxicity. Many amelioration measures such as use of minerals (for example, zinc, calcium, and iron), vitamins (vitamin C, A, and E), different herbs, probiotics and other agents (taurine, bentonite, chitosan, zeolite, and metallothionein) have been explored for their effective roles to reduce Cd bioaccumulation and toxicity symptoms in fishes. The present review discusses bioaccumulation of Cd, histopathological alterations, oxidative stress, synergism-antagonism, and gene regulation in different tissues, and its amelioration measures in fishes.

Metallic trace element dynamics in Paracentrotus lividus from Algeria: Environmental and human health risk assessment

This paper evaluates the dynamic of Metallic Trace Elements (MTEs; Cd, Pb, Fe, Cu, Zn, Ni and Co) in the sea urchin Paracentrotus lividus collected in five sites: four contaminated and one reference, along the western coast of Algeria, recontextualizes this contamination within a wider geographical distribution area throughout 84 sites among the Mediterranean Sea and Atlantic and focuses on the potential risk on human health for the first time in Algeria. The Trace Element Pollution Index places Algeria, and generally the North African coasts, as the region most contaminated by MTEs. The Trace Element Spatial Variation Index ranks Pb as a MTE of key environmental concern according to global spatial variability. The health risk assessment indicates that Cd and Pb exceed the maximum limits set by the Commission Regulation (EC) No 1881/2006 on three of the four contaminated sites.

Acute Toxicity Bioassay and Determination of LC50 of Cadmium Chloride in Trichogaster (Colisa) fasciata

Cadmium chloride is a metal salt used in industries in a large scale. Trichogaster (Colisa) fasciata (common name banded gourami) is an air-breathing fresh water fish with both nutritional and ornamental values. In this present study, as per EPA guidelines, acute toxicity bioassay was performed in a 96-h static test method in four replicates, each replicate having one control and five concentrations (25, 50, 75, 100 and 125 mg/L, respectively) of the metal salt. A total of 192 fish was used in the study in four series with each replicate containing 8 fish per concentration. The water temperature was maintained at 20-22℃ during the study. The data observed were analysed statistically on the basis of Finney's Probit Analysis method using SPSS software. The estimated 96-h LC₅₀ value of cadmium chloride for the fish was 49.5 mg/L.

Cadmium toxicity symptoms and uptake mechanism in plants: a review

Cadmium (Cd) is one of non-essential heavy metals which is released into environment naturally or anthropogenically. It is highly persistent toxic metals that are exceptionally distressing industrial and agriculture activities by contaminating soil, water and food. Its long-duration endurance in soil and water results in accumulation and uptake into plants, leading to the food chain. This becomes a serious global problem threatening humans and animals as food chain components. Living organisms, especially humans, are exposed to Cd through plants as one of the main vegetative food sources. This review paper is concentrated on the symptoms of the plants affected by Cd toxicity. The absorption of Cd triggers several seen and unseen symptoms by polluted plants such as stunted growth, chlorosis, necrosis and wilting. Apart from that, factors that affect the uptake and translocation of Cd in plants are elaborated to understand the mechanism that contributes to its accumulation. By insight of Cd accumulation, this review also discussed the phytoremediation techniques-phytoextraction, phytostimulation, phytostabilization, phytovolatization and rhizofiltration in bioremediating the Cd.

Tissue Bioaccumulation and Toxicopathological Effects of Cadmium and Its Dietary Amelioration in Poultry-a Review

Cadmium (Cd) has been recognized as one of the most toxic heavy metals, which is continuously discharged into environments through anthropogenic (industrial activities, fertilizer production, and waste disposal) and natural sources with anthropogenic sources contributing greater than the natural sources. Therefore, Cd concentration sometimes increases in feeds, fodders, water bodies, and tissues of livestock including poultry in the vicinity of the industrial areas, which causes metabolic, structural, and functional changes of different organs of all animals. In poultry, bioaccumulation of Cd occurs in several organs mainly in the liver, kidney, lung, and reproductive organs due to its continuous exposure. Intake of Cd reduces growth and egg laying performance and feed conversion efficiency in poultry. Chronic exposure of Cd at low doses can also alter the microscopic structures of tissues, particularly in the liver, kidney, brain, pancreas, intestine, and reproductive organs due to increased content of Cd in these tissues. Continuous Cd exposure causes increased oxidative stress at cellular levels due to over-production of reactive oxygen species, exhausting antioxidant defense mechanisms. This leads to disruption of biologically relevant molecules, particularly nucleic acid, protein and lipid, and subsequently apoptosis, cell damage, and necrotic cell death. The histopatholocal changes in the liver, kidneys, and other organs are adversely reflected in hemogram and serum biochemical and enzyme activities. The present review discusses about Cd bioaccumulation and histopathological alterations in different tissues, pathogenesis of Cd toxicity, blood-biochemical changes, and its different ameliorative measures in poultry.

An automated computer vision based preliminary study for the identification of a heavy metal (Hg) exposed fish-channa punctatus

Fishes available in the market may be cultured either in fresh or contaminated water bodies. Heavy metals are one of those contaminants which may cause menace to fish health and thereby affect the health of living beings consuming them. The identification of heavy metal residues in fish samples is a challenging task and may require expensive and sophisticated instruments and testing. This paper investigates visual changes which may be used as benchmark for differentiating between fresh water and heavy metal exposed fishes. The proposed method is an automated non-destructive image processing method for identifying visual changes which can be used to differentiate between controlled (untreated) and heavy metals exposed (treated) fishes. The eye of the fish from digital images is considered as focal tissue that was automatically segmented using the Circular Hough Transform and adaptive intensity thresholding. Post segmentation, a potential feature is identified and transformed into mathematical parameters for classification of a fish sample as fresh or heavy metal exposed water fish. The proposed method can identify and translate the potential visual feature for ease of understanding. The accuracy of the proposed method is high, and computation time elapsed indicates the possibility of using such algorithm for real time detection in related field.

Estimation of cadmium content in Egyptian foodstuffs: health risk assessment, biological responses of human HepG2 cells to food-relevant concentrations of cadmium, and protection trials using rosmarinic and ascorbic acids

Cadmium (Cd) is an environmental pollutant that can get entry into human body via ingestion of contaminated foods causing multiple organ damage. This study aimed at monitoring Cd residues in 20 foodstuffs of animal origin that are commonly consumed in Egypt. Health risk assessment was conducted via calculation of Cd dietary intakes and non-carcinogenic target hazard quotient. An in vitro approach was performed to investigate the constitutive effects of Cd on human hepatoma (HepG2) cells under food-relevant concentrations. Trials to reduce Cd-induced adverse effects on HepG2 cells were done using rosmarinic (RMA) and ascorbic acids (ASA). The achieved results indicated contamination of the tested foodstuffs with Cd at high levels with potential human health hazards. Cd at food-relevant concentrations caused significant cytotoxicity to HepG2 cells. This may be attributed to induction of oxidative stress and inflammation, as indicated by the overexpression of stress and inflammatory markers. At the same time, Cd downregulated xenobiotic transporters and upregulated the proliferation factors. Co-exposure of HepG2 cells to Cd and micronutrients such as RMA and ASA led to recovery of cells from the oxidative damage, and subsequently cell viability was strongly improved. RMA and ASA ameliorated the biological responses of HepG2 cells to Cd exposure.

Metal contamination in quail meat: residues, sources, molecular biomarkers, and human health risk assessment

Quail meat is an emerging source of high-quality animal protein. Quails are exposed to a wide range of xenobiotics such as heavy metals. In this study, residual concentrations of four toxic metals, of significant public health importance, including cadmium (Cd), lead (Pb), arsenic (As), and nickel (Ni), were determined in edible tissues of quails. In addition, metal loads were measured in water, feed, and litter samples collected from same quail farms as possible sources for quail exposure to heavy metals. The possible use of metallothionein (MT) and heat shock protein 70 (Hsp70) as molecular biomarkers of exposure to heavy metals was further investigated. Furthermore, the dietary intake and the potential risk assessment of the examined heavy metals among children and adults were calculated. The edible tissues of quails contained high concentrations of four heavy metals (contents (ppm/ww) ranging from 0.02 to 0.32 in Cd, 0.05 to 1.96 in Pb, 0.002 to 0.32 in As, and 1.17 to 3.94 in Ni), which corresponded to the high contents of these metals in the feeds, water, and litter. MT and Hsp70 mRNA expressions showed positive correlations with the concentrations of heavy metals in tissues indicating the possibility to use these proteins as biomarkers for quail's exposure to toxic metals. Dietary intake of quail meat and risk assessment revealed potential risks especially for children after prolonged exposure to the examined metals. Thus, legislations should be established and continuous screening of metal residues should be adopted in order to reduce the toxic metal concentrations in feeds and drinking water for quails. Reduction of exposure to heavy metals subsequently would lead to minimization of exposure of such toxicants through consumption of quail meat.

Bioaccumulation of selected heavy metals and histopathological and hematobiochemical alterations in backyard chickens reared in an industrial area, India

This study was carried out to determine the concentrations of four heavy metals, cadmium (Cd), lead (Pb), copper (Cu), and cobalt (Co), and histopathological lesions in tissues of chickens reared in an industrial area of West Bengal, India. In particular, Mejhia Block was selected as a heavy metal-exposed area and Vatar Block (120 km away from industrially polluted areas) as a reference site. Samples were collected from the backyard chickens in these areas. Concentrations of heavy metals in soil, water, feedstuffs, tissues (liver, kidney, spleen, lung, and muscle), and droppings were greater (p < 0.05) in the polluted site than in the reference site. The greatest tissue concentrations of Cd and Pb were noted in the kidney, followed by the liver, lung, spleen, and muscle, whereas Cu and Co concentrations accumulated in these tissues resulted in the following: liver > kidney > lung > spleen > muscle. Heavy metal concentrations were greater in older chickens (> 1 year) than in young chickens (< 1 year). Packed cell volume, total erythrocyte counts, hemoglobin, total protein, and total leucocyte counts were significantly (p < 0.01) lower in the blood picture of chickens in the exposed area. Different serum enzymes and biochemical profiles were altered due to heavy metal exposure. Histological changes revealed necrotic lesions and tubulitis in the kidney, degeneration and necrosis in liver parenchyma, and periarteriolitis, peribronchiolitis, and presence of hemosiderin pigment in the lung of chickens in the exposed site. Results indicated that backyard chickens in heavy metal-exposed site may show pathological lesions in different tissues due to accumulation of heavy metals, and thus, the consumption of chicken meat from the industrially exposed site may pose a potential health risk to local residents of polluted sites.

Selenium deficiency-induced alterations in ion profiles in chicken muscle

Ion homeostasis plays important roles in development of metabolic diseases. In the present study, we examined the contents and distributions of 25 ions in chicken muscles following treatment with selenium (Se) deficiency for 25 days. The results revealed that in chicken muscles, the top ranked microelements were silicon (Si), iron (Fe), zinc (Zn), aluminum (Al), copper (Cu) and boron (B), showing low contents that varied from 292.89 ppb to 100.27 ppm. After Se deficiency treatment, essential microelements [Cu, chromium (Cr), vanadium (V) and manganese (Mn)], and toxic microelements [cadmium (Cd) and mercury (Hg)] became more concentrated (P < 0.05). Elements distribution images showed generalized accumulation of barium (Ba), cobalt (Co), Cu, Fe and V, while Cr, Mn, and Zn showed pin point accumulations in muscle sections. Thus, the ion profiles were generally influenced by Se deficiency, which suggested a possible role of Se deficiency in muscle dysfunctions caused by these altered ion profiles.

The Antagonistic Effect of Selenium on Lead Toxicity Is Related to the Ion Profile in Chicken Liver

The interactions between the essential element selenium (Se) and the toxic element lead (Pb) have been reported extensively; however, limited data are available regarding the effects of Se on Pb and the ion profile in chicken liver. Whether the change in the ion profile was involved in the protective process of Se and the toxic effect of Pb is unknown. In the present study, we detected 26 ion profiles (including those of Na, Mg, K, Ca, B, Si, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, Mo, Sb, Ba, Tl, Li, Al, As, Cd, Sn, Hg, and Pb) in chicken liver following treatment with Se or Pb and with the compound treatment of Se and Pb. The results showed that Se supplementation decreased the content of B and Cr and increased that of Zn and Ba (P < 0.05); however, Pb exposure decreased Cr, Mn, Cu, Se, Mo, and Hg and increased V, Fe, Cd, and Sn (P < 0.05). The results showed that Se and Pb primarily influenced essential microelements and toxic microelements in the chicken liver. In this process, Se alleviated the increased Cd and Pb induced by Pb exposure but aggravated the decreased Cu and Mn. The results also indicated that there existed both synergistic and antagonistic interactions between different ions, further verifying the principal component analysis. Thus, the results showed that prolonged exposure to Se and Pb influences the ion profiles in chicken liver. The protective role of Se and toxic effect of Pb may be related to these changing ion profiles in chicken liver.

Metal concentrations and histopathological changes in goats (Capra hircus) reared near an industrial area of West Bengal, India

The present investigation was performed to assess the concentrations of four heavy metals-lead (Pb), cadmium (Cd), copper (Cu), and cobalt (Co)-in goats reared in the vicinity of an industrial area of West Bengal, India, including soil, water, and feedstuffs; tissues of liver, kidney, lung, spleen, and muscle; and milk and faeces. In addition, histopathological changes in liver, lung, kidney, spleen, and muscle samples were examined. Mejia block as an industrial polluted site and Vatar block as a reference site (without any industrial activities and 120 km away from the polluted site) were selected for this study. The results showed that concentrations of these heavy metals in soil, water feedstuffs, all tissues, milk, and faeces were greater (P < 0.05) in the polluted site than the reference site. The largest concentrations of Cd and Pb were found in kidney followed by liver, lung, spleen, and muscle. However, Co and Cu accumulations in the tissues were in following order: liver > kidney > lung > spleen > muscle. Concentrations of heavy metals were greater in older animals than in young ones. Haemoglobin, total protein, packed cell volume, total erythrocyte counts, and total leucocytes counts were significantly (P < 0.01) decreased in blood of goats in the polluted site compared with the reference site. Serum glucose, creatinine, aspartate amino transferase, alanine amino transferase, and alkanline phosphatase were significantly (P < 0.05 to P < 0.01) increased. Histological examination showed several pathological alterations including degeneration, vacuolation, and tubulitis in kidney; congestion, degeneration, periportal necrosis, and focal haemorrhages in liver; and congestion and diffuse haemorrhage in lungs. It was concluded that natural exposure to these environmental heavy metals significantly increases toxic heavy-metal concentrations in several visceral organs resulting in pathological changes in these tissues. Thus, consumption of the meat of goats reared in the polluted site may pose human health hazards.

Cadmium supplement triggers endoplasmic reticulum stress response and cytotoxicity in primary chicken hepatocytes

Cadmium (Cd), a potent hepatotoxin, has been reported to induce endoplasmic reticulum (ER) stress in various cell types. However, whether such effect exists in bird is still unclear. To delineate the effects of Cd exposure on ER stress response, we examined the expression of 78-kDa glucose-regulated protein (GRP78) and alteration in calcium homeostasis in primary chicken hepatocytes treated with 2-22 µM Cd for 24 h. A significant decrease of cell viability was observed in chicken hepatocytes following Cd administration. In cells treated with Cd, GRP78 protein levels increased in a dose-dependent manner. In addition, GRP78 and GRP94mRNA levels were elevated in response to Cd exposure. The increase of the intracellular Ca(2+) concentration in chicken hepatocytes was found during Cd exposure. Cd significantly decreased the CaM mRNA levels in hepatocytes. These results show that Cd regulates the expression of GRP78 and calcium homeostasis in chicken hepatocytes, suggesting that ER stress induced by Cd plays an important role in the mechanisms of Cd cytotoxicity to the bird hepatocytes.

Cadmium induced hepatotoxicity in chickens (Gallus domesticus) and ameliorative effect by selenium

Cadmium (Cd) is one of the most toxic metal compounds released into the environment. It was well known that Cd induced hepatotoxicity in animal models. However, little is known about the negative effects of Cd toxicity in the liver of birds. To investigate the Cd hepatotoxicity in birds and the protective effects of selenium (Se) against subchronic exposure to dietary Cd, 100-day-old cocks received either Se (as 10mg Na2SeO3 per kg of diet), Cd (as 150mg CdCl2 per kg of diet) or Cd+Se in their diets for 60 days. Histological and ultrastructural changes in the liver, the concentrations of Cd and Se, the lipid peroxidation (LPO) and nitric oxide (NO) production, the activities of the antioxidants superoxide dismutase (SOD) and glutathione peroxidase (GPx), nitric oxide synthase (NOS) activities and apoptosis were determined. Exposure to Cd significantly reduced SOD and GPx activity, Se content in the liver tissue. It increased the LPO and NO production, the numbers of apoptotic cells and Cd concentration and caused obvious histopathological changes in the liver. Concurrent treatment with Se reduced the Cd-induced liver histopathological changes, oxidative stress, overexpression of NO and apoptosis, suggesting that the toxic effects of Cd on the liver is partly ameliorated by inorganic Se. Se supplementation also modified the distribution of Cd in the liver.

Spatial analysis of Cd and Pb in the Pike (Esox lucius) from Western Anzali wetlands of Iran

Geostatistical studies are used to estimate pollution burden in aquatic ecosystems and to plan large-scale control programs to protect these environments. Geostatistical studies allow us to predicted pollutant concentrations for areas that have not been sampled. This is done by taking into account the spatial correlations between estimated and sampled points and by minimizing the variance of estimation error. The use of geostatistical techniques in biomonitoring of fish species can illuminate extent and source of pollution, thereby providing an effective tool for developing intervention strategies to protect such environments. This study investigates the spatial distribution patterns of cadmium and lead in the Pike (Esox lucius). Fish were captured in the western parts of the Anzali wetlands located on the Caspian Sea in Iran. The muscle tissue of Anzali Pike had 5 ± 0.25 and 168 ± 18.4 (ng/g dw) cadmium and lead, respectively. Positive relationships were detected between Pike's length and weight (r = 0.85, p < 0.05), length and age (r = 0.35, p < 0.05), and muscle cadmium and lead (r = 0.45, p < 0.05). By contrast, there was a negative relationship between lead levels and weight in Pike (r = -0.36, p < 0.05). For both metals, the resulting metal concentration maps indicated higher pollutant concentrations in the southeast parts of the study area. Considerable boat traffic activity and agricultural activity contribute to the pollution in these areas, undermining the integrity of local habitat for fish survival and reproduction.

Effect of dietary cadmium on lipid metabolism and storage of aquatic bird Cairina moschata

In environment, birds often fast in connection with breeding, migration or drastic climatic conditions and need to mobilize lipid reserves during these periods. The impairment of lipid metabolism by cadmium (Cd; 1 mg kg(-1) added in diet) was investigated on palmiped Cairina moschata. Expression levels of genes involved in lipid metabolism, mitochondrial metabolism and detoxification were investigated in liver and muscle of ducks. Lipid content in muscle and liver were analysed and plasma triglycerides were quantified. After 20 days, ducks exposed to Cd displayed a lower body weight and lower lipid content in liver than controls. In muscle, the increase of lipid content was only significant for control ducks but not for exposed ducks. Exposed ducks appeared unable to sufficiently transport and store lipids into peripheral tissues. Cd impairs lipid metabolism by several ways. First, Cd triggered the down-regulation of fatty acids synthesis in liver even if the NADPH production and the mitochondrial metabolism are enhanced, suggesting a stronger energy needs. Secondly, the associated decrease of plasma triglycerides and lipoprotein lipase activity with Cd are consistent with impairment of lipids storage in peripheral tissues.

Ascorbic acid, garlic extract and taurine alleviate cadmium-induced oxidative stress in freshwater catfish (Clarias batrachus)

An experiment was conducted to investigate bioaccumulation potential of cadmium (Cd) and changes in oxidative stress indices in liver and kidney tissues from Cd-exposed catfish (Clarias batrachus) with or without simultaneous treatment of water with ascorbic acid, garlic extract or taurine. C. batrachus (n=324) with average length of 20+/-4 cm and weight of 86+/-5 g were used for the present investigation. Fishes were divided into nine groups (I to IX) each comprising 36 fishes. The fishes of groups II, III, IV and V were challenged with 5 ppm of cadmium chloride monohydrate (CdCl2.H2O), whereas groups VI, VII, VIII and IX were exposed to 10 ppm CdCl2.H2O solution for a period of 45 days. Group I was kept as negative control and the fishes of this group were maintained in water containing no added Cadmium. Group II and VI were maintained as Cd exposed non treated control to serve as positive controls. Fishes of III and VII, IV and VIII, V and IX received ascorbic acid (5 ppm), extract of dried garlic (5 ppm) or taurine (5 ppm), respectively during the entire experiment period. The concentrations of Cd in liver and kidney increased significantly following exposure to Cd and the level continued to rise with the increase in exposure duration. Treatment of tank water with ascorbic acid, garlic or taurine significantly reduced the Cd concentrations in tissues compared to the positive control group, but the level in Cd exposed groups was greater than the negative control group. Fishes exposed to Cd and treated with ascorbic acid, garlic or taurine had reduced oxidative stress as evidenced from lower concentration of lipid peroxides and higher activities of superoxide dismutase and catalase in liver, kidney and erythrocytes compared to fishes exposed to Cd. The reduction in Cd induced oxidative stress was highest in ascorbic acid treated group followed by garlic and taurine treatment. The results suggest that ascorbic acid, garlic and taurine have potential to reduce tissue accumulation of Cd and associated oxidative stress in freshwater catfish.