Tissue Arsenic Concentrations Research Articles

A study of the subchronic effects of arsenic exposure on the liver tissues of Labeo rohita using Fourier transform infrared technique

In this work, an attempt has been made to study the subchronic effects of arsenic exposure on the biochemical composition; mainly proteins of the liver tissues of Labeo rohita fingerlings by using Fourier transform infrared (FT-IR) spectroscopic technique. The study was carried out using a Perkin Elmer-Spectrum Rx1 spectrometer. Because of arsenic exposure, significant reductions in the intensity as well as area of amide bands have been observed in the liver tissues. The decreased intensity of the amide bands could be interpreted as the result of alteration of the protein synthesis due to the high affinity of metal compounds towards different amino acid residues of proteins. Further, meso-2, 3-dimercaptosuccinic acid (DMSA) treatment shows the recovery of the protein content in the liver tissues. To confirm that the changes observed are only due to the bio-accumulation of arsenic, the concentration of arsenic in the liver tissues of Labeo rohita was determined by using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). It is observed that the arsenic level in the control tissues is found to be below detectable limit, whereas the arsenic exposed liver shows an accumulation of 66.68 ± 0.43 μg/g and DMSA treatment reduces the arsenic content to 17.96 ± 0.19 μg/g. In conclusion, this study gives clear evidence that the use of FT-IR spectroscopy is a powerful approach to achieve more insight into the protein alterations caused by arsenic.

Trace Metal Concentrations in Sediments and Fish in the Vicinity of Ash Lagoon Discharges from Coal-Combustion Plants in New Brunswick and Nova Scotia, Canada

Metals that originate from coal-combustion residue (ash) deposited in water-filled lagoons are eventually released into the environment. This study measured metal concentrations in sediment and fish obtained in the vicinity of two coal-combustion ash-lagoon outfalls on the East River (Nova Scotia) and Grand Lake (New Brunswick), Canada. Of the 34 metals analysed, this study demonstrated that sediment in the immediate vicinity of the ash lagoon discharge in New Brunswick had statistically significant greater concentrations of thallium, arsenic, and antimony than did the sediment obtained from background areas. Tissue arsenic concentrations were increased in fish obtained near the lagoon discharge in New Brunswick but not statistically greater than that of fish obtained from background areas. Neither sediment nor fish obtained near the ash-lagoon discharge in Nova Scotia had significantly greater concentrations of any of the metals measured.

Therapeutic efficacy of silymarin and naringenin in reducing arsenic-induced hepatic damage in young rats

We investigated the effects of silymarin and naringenin in counteracting arsenic-induced hepatic oxidative stress post exposure. Male wistar rats were chronically exposed to sodium arsenite for eight months followed by oral treatment with silymarin and naringenin (50 mg/kg each) for 15 consecutive days to evaluate hepatic damage and antioxidant potential. Our results demonstrate a significant decrease in hepatic GSH levels, SOD and catalase activities and an increase in GST and TBARS levels after arsenic administration. Silymarin or naringenin administration increased GSH levels and was beneficial in the recovery of altered SOD and catalase activity besides significantly reducing blood and tissue arsenic concentration. Our results point to the antioxidant potential of these flavonoids, which might be of benefit in the clinical recovery of subject exposed to arsenic. These flavonoids can be incorporated into the diet or co-supplemented during chelation treatment, and thus may afford a protective effect against arsenite-induced cytotoxicity.

The European maximum level for cadmium in bovine kidneys is in Belgium only realistic for cattle up to 2 years of age

The effect of animal age on concentrations of cadmium, lead, arsenic, copper and zinc in bovine tissues (meat, kidney and liver) sampled from animals reared in contaminated areas or reference regions in Belgium was investigated. For cadmium concentrations in meat samples analysis of variance (ANOVA) showed an increasing trend with age. In addition, a significant positive linear relation (p < 0.05) was found between animal age and renal (R 2 = 0.56) or hepatic (R 2 = 0.39) cadmium levels. Lead concentrations in kidneys and liver also increased with age, but the effect was blurred, likely due to the internal remobilization of lead. For the other trace elements (arsenic, copper, zinc) no relationship could be found between their concentration in meat, kidneys or liver and animal age. Renal cadmium concentrations were predicted for bovines at different ages by using the slope of the linear regression equation, and by taking into account its 95% confidence interval. Calculations for 2-year-old animals from reference areas showed that in this group the European maximum level of 1 mg kg−1 for cadmium in kidneys would be exceeded in zero to 5% of cases. If a general rejection percentage of maximum 5% would be desirable for kidneys sampled in the reference areas (according to the ALARA principle–‘as low as reasonably achievable’–of European Union policy), then (1) kidneys from animals older than 2 years from the reference areas should a priori not be considered suitable to be placed on the market, or (2) the maximum level for cadmium in kidneys should be increased to 3 mg kg−1. The latter would bear negligible risks for the general population and the majority of high-level kidney consumers. On the other hand, bovine kidneys from the most contaminated areas are not suitable to be brought into the food chain because it is predicted that the maximum level is already exceeded by more than 5% of the 1-year-old animals.

The fate of arsenic in soils adjacent to an old mine site (Bustarviejo, Spain): mobility and transfer to native flora

The mobility of arsenic in soils and its transfer to other environmental components present significant environmental risks. The management of polluted land is determined by the availability, mobility, and transfer of inorganic pollutants to different ecosystem compartments. In this paper, the fate of arsenic at this mining site has been evaluated to determine future management practises to minimise such risk. In a field study carried out in the area adjacent to a mining site at Bustarviejo (North Madrid, Spain), samples of soils, plants, and water were collected from areas adjacent to the core of the former mining activity. The following parameters were investigated in soil samples: pH, organic matter, pseudo-total As, P, and Fe, and labile As and P, and a sequential extraction procedure was performed to investigate As speciation in soil. Plant materials were analysed for both As and P. Arsenic concentrations in water samples (surface and soil pore water collected in the field) were also measured. Results are considered in tandem with previous data on metal concentrations in soils and plants from this site. Despite high As concentrations in soils impacted by former mining activities (spoil accumulation and drainage from spoil heaps resulted in concentrations of up to 3,000 mg kg−1), it was not present in a labile form. Sequential extraction revealed that arsenic was mainly retained by Al- and Fe-(oxihydr)oxides (up to 80%). Therefore, only a small proportion of the total soil pool was potentially available for plant uptake (0.3% and 7% extracted by (NH4)2SO4 and NH4H2PO4, respectively). There was very limited transfer of arsenic from soil to plants, and concentrations of arsenic in shoot tissues were relatively low (<8 μg g−1). There was no evidence of phytotoxic effects in the flora that had colonised this site, indicating that a sustainable ecosystem had been established. High levels of arsenic occur at this site, but arsenic mobility appears to be primarily controlled by the presence of amorphous and crystalline Fe and Al hydrous oxides. Although a low labile As fraction was extracted, concentrations of arsenic in both surface and soil pore water are of concern. The risk of arsenic remobilisation by plant uptake or transfer to the food chain via plant consumption is relatively low in these soils. Large amounts of metals and arsenic remain at the site, and potential risks need to be monitored. Some possible remediation strategies that take into account the presence of both arsenic and heavy metals will be suggested. Natural attenuation and phytostabilisation processes are taking place in several parts of the study area. These natural processes could be enhanced by application of both compost and a suitable Fe-based amendment. This augmentation of the re-vegetation of the affected area could act to promote both arsenic and metal stabilisation in mine tailings with additional benefits for further vegetation establishment.

Effect of Spirulina on Biochemical Parameters and Reduction of Tissue Arsenic Concentration in Arsenic Induced Toxicities in Ducks

The present study was undertaken for the effect of spirulina on biochemical parameters and reduction of tissue arsenic concentration in arsenic induced toxicities in ducks. One hundred and seventy 5 ducklings were divided into five equal groups separately. One group (T ) of ducklings was kept as control. 0 One group (T ) of ducklings were given arsenic trioxide @ 100 mg/L drinking water and rest three groups of 1 ducklings (T , T and T ) were given arsenic trioxide @ 100 mg/L plus spirulina in three different doses i.e. 2 3 4 30, 60 and 120 mg/L in drinking water daily for 90 days starting from day 15. Five birds were sacrificed from each group in every 15 day intervals and biochemical parameters were determined. All the biochemical parameters (SGPT, SGOT, ALP, LDH and ACP) were significantly (p<0.01) elevated in arsenic treated groups. However, the elevation of these parameters was less in arsenic plus spirulina treated groups (T , T and T ). 2 3 4 The distribution of arsenic concentration was highest in liver and lowest in faeces. Maximum reduction of arsenic was recorded in all organs following highest doses of spirulina (120 mg/L). The present study reveals that spirulina may be helpful for reducing the tissue burden of arsenic in ducks.

Partitioning Species Variability from Soil Property Effects on Phytotoxicity: ECx Normalization Using a Plant Contaminant Sensitivity Index

Soil properties mitigate hazardous effects of contaminants through soil chemical sequestration and should be considered when evaluating ecological risk from terrestrial contamination. Empirical models that quantify relationships between soil properties and toxicity to ecological receptors are necessary for site-specific adjustments to ecological risk assessments. However, differential sensitivities of test organisms in dose-response studies may limit the utility of such models. We present a novel approach to toxicity estimation that partitions the effect of differential sensitivities of test organisms from that of soil chemical/physical properties. Five soils that ranged in selected properties were spiked with five concentrations of sodium arsenate. Bioassays were conducted where above ground dry matter growth and the corresponding tissue arsenic concentrations were evaluated for three terrestrial plants (Alfalfa, Medicago sativa L.; Perennial ryegrass, Lolium perrene L.; and Japanese millet, Echinochloa crusgalli L.). Estimates were combined into a plant contaminant sensitivity index (PCSI) and used to normalize phytotoxicity parameters to the most sensitive species (i.e., alfalfa) where necessary. Simple linear regression and ANCOVA indicated a 36.5% increase in the explanatory power of the modifying effects of soil properties on phytotoxicity when differential arsenate sensitivities were accounted for by PCSI (r(2) = 0.477-0.833). Normalization of ecotoxicity parameters by PCSI is a seemingly effective approach to quantify the modifying effects of soil properties on phytotoxicity endpoints when it is of interest to consider multiple plant species (or varieties within a species) with differential sensitivities to experimental contaminants.

Comparison of electrothermal and hydride generation atomic absorption spectrometry for the determination of total arsenic in broiler chicken

The purpose of this study was to estimate total arsenic concentration in different tissues (leg, breast, liver and heart) of broiler chicken by hydride generation atomic absorption spectrometry (HGAAS) and graphite furnace atomic absorption spectrometry (GFAAS), prior to microwave assisted acid digestion. The accuracy of the techniques was evaluated by using certified reference material DORM-2. The percentage recoveries of total As were observed as 100.6% and 99.4% for HGAAS and GFAAS, respectively. The precision of the techniques, expressed as relative standard deviation, was observed as 1.71% and 4.18% for HGAAS and GFAAS measurements, respectively. The limits of detection for HGAAS and GFAAS were 0.025 μg/g and 0.052 μg/g, respectively. The concentrations of total arsenic in different tissues of broiler chicken were found in the range of 2.19–5.28, 2.15–5.22, 2.97–7.17 and 2.68–6.36 μg/g for leg, breast, liver and heart tissues, respectively. At a mean level of chicken consumption (60 g/person/day), people may ingest in the range of 72.0–85.1 μg arsenic/person/day from chicken alone.

Heavy Metal Distribution in Tissues of Six Fish Species Included in Human Diet, Inhabiting Freshwaters of the Nature Park “Hutovo Blato” (Bosnia and Herzegovina)

The aim of the study was to quantify heavy metal (mercury, lead, cadmium, and arsenic) concentration in tissues (muscles, liver, kidney, gills, and gonads) of six fish species (carp: Cyprinus carpio, tench: Tinca tinca, pumpkinseed: Lepomis gibosus, prussian carp: Carassius auratus gibelio, hasselquist: Salmo dentex, eel: Anguilla anguilla) from the freshwaters of the Nature Park Hutovo Blato, Bosnia and Herzegovina, and determine whether they are potentially harmful for human health if included in the diet. Fish were angled from the Svitava Lake in the second part of August of the year 2003, and fish tissues were stored at -18 degrees C until analysis. Heavy metal concentration was determined by atomic absorption spectrophotometry in the Veterinary Institute Brno, Czech Republic, and expressed as mg.kg(-1) of wet tissue. Concentration of mercury, lead, and arsenic in most tissues of all analyzed fish types is lower than the maximal allowed concentration (MAC) in most countries. Cadmium concentration is also low in muscles and gonads, but kidney, liver, and gill concentrations exceed MAC value in most countries. Hasselquist, an endemic type for that region, differs from other fish types in the fact that it has very low cadmium concentration in liver and kidney, but the highest concentration of arsenic in most tissues, especially muscles. In muscles and gonads of all fish types analyzed, Pb is present in higher concentration than Cd, whereas in liver, gills, and particularly kidney, the situation is opposite, suggesting diverse metabolic pathways and unequal bioaccumulation of these two metals in different fish tissues. Although the region of the Nature Park Hutovo Blato in Bosnia and Herzegovina is not an agricultural territory, the intensive agricultural activities in the neighboring regions already result in high cadmium concentration in inner organs of fish species analyzed. Therefore, fish types in the freshwaters of the Park may be included in the human diet, but without inner organs and gills (or the whole head).

Arsenic accumulation and speciation in freshwater fish living in arsenic-contaminated waters

Environmental context. Inorganic arsenic, a well-known human carcinogen, represents a major worldwide environmental problem because contaminated water supplies have lead to widespread human exposure. This study investigates the arsenic content of freshwater fish from arsenic-contaminated and non-contaminated sites in Thailand, and reports high arsenic concentrations and significant amounts of inorganic arsenic in the edible muscle tissue. The data suggest that freshwater fish may represent a significant source of inorganic arsenic to some human populations. Abstract. Striped snakehead (Channa striata), carnivorous freshwater fish that serve as popular food in Thailand, were collected from a reference site (1.4 µg As L–1) and from two arsenic-contaminated ponds (Pond A, 550 µg As L–1; Pond B, 990 µg As L–1) in southern Thailand and analysed for arsenic by inductively coupled plasma mass spectrometry (ICPMS) and for arsenic species by HPLC-ICPMS performed on aqueous methanol extracts of muscle, liver and gill (n = 3 fish from each site). Mean total arsenic concentration in muscle tissue of C. striata collected from the reference site was 1.9 µg As g–1 (dry mass) while fish from the contaminated sites contained 13.1 µg As g–1 (Pond A) and 22.2 µg As g–1 (Pond B). Liver and gill tissues showed similar increasing arsenic concentrations on going from the reference site to Ponds A and B, with Pond B showing the highest levels. Speciation analysis on the three tissues showed that, although arsenate was the major extractable arsenical in reference fish (e.g. 0.73 µg As g–1 in muscle tissue), dimethylarsinate was by far the dominant arsenic species in fish from the two contaminated sites. Three non-carnivorous fish species (Danio regina, Rasbora heteromorpha and Puntius orphoides), collected from Pond B only, had lower arsenic concentrations (7.9–11.3 µg As g–1 in muscle tissue) than did C. striata, and contained appreciable amounts of trimethylarsine oxide together with two other major arsenicals, arsenate and dimethylarsinate, and smaller quantities of arsenite and methylarsonate. The study shows for the first time a clear effect of water arsenic concentrations on natural fish tissue arsenic concentrations, and is the first report of a freshwater fish species attaining arsenic concentrations comparable with those found in marine fish species. Furthermore, the high concentrations of toxic inorganic arsenic (predominantly arsenate) in the muscle tissue of the edible fish C. striata have human health implications and warrant wider investigations.

Concomitant administration of Moringa oleifera seed powder in the remediation of arsenic‐induced oxidative stress in mouse

Contamination of ground water by arsenic has become a cause of global public health concern. In West Bengal, India, almost 6 million people are endemically exposed to inorganic arsenic by drinking heavily contaminated groundwater through hand-pumped tube wells. No safe, effective and specific preventive or therapeutic measures for treating arsenic poisoning are available. We recently reported that some of the herbal extracts possess properties effective in reducing arsenic concentration and in restoring some of the toxic effects of arsenic in animal models. Moringa oleifera Lamarack (English: Horseradish-tree, Drumstick-tree, Hindi: Saijan, Sanskrit: Shigru) belongs to the Moringaceae family, is generally known in the developing world as a vegetable, a medicinal plant and a source of vegetable oil. The objective of the present study was to determine whether Moringa oleifera (M. oleifera) seed powder could restore arsenic induced oxidative stress and reduce body arsenic burden. Exposure to arsenic (2.5 mg/kg, intraperitoneally for 6weeks) led to a significant increase in the levels of tissue reactive oxygen species (ROS), metallothionein (MT) and thiobarbituric acid reactive substance (TBARS) which were accompanied by a decrease in the activities in the antioxidant enzymes such as superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) in mice. Arsenic exposed mice also exhibited liver injury as reflected by reduced acid phosphatase (ACP), alkaline phosphatase (ALP) and aspartate aminotransferase (AST) activities and altered heme synthesis pathway as shown by inhibited blood delta-aminolevulinic acid dehydratase (delta-ALAD) activity. Co-administration of M. oleifera seed powder (250 and 500 mg/kg, orally) with arsenic significantly increased the activities of SOD, catalase, GPx with elevation in reduced GSH level in tissues (liver, kidney and brain). These changes were accompanied by approximately 57%, 64% and 17% decrease in blood ROS, liver metallothionein (MT) and lipid peroxidation respectively in animal co-administered with M. oleifera and arsenic. Another interesting observation has been the reduced uptake of arsenic in soft tissues (55% in blood, 65% in liver, 54% in kidneys and 34% in brain) following administration of M. oleifera seed powder (particularly at the dose of 500 mg/kg). It can thus be concluded from the present study that concomitant administration of M. oleifera seed powder with arsenic could significantly protect animals from oxidative stress and in reducing tissue arsenic concentration. Administration of M. oleifera seed powder thus could also be beneficial during chelation therapy with a thiol chelator.

Effects of combined administration of captopril and DMSA on arsenite induced oxidative stress and blood and tissue arsenic concentration in rats

We compared the therapeutic efficacy of captopril and a thiol chelating agent, meso 2,3-dimercaptosuccinic acid (DMSA) either individually or in combination against arsenite induced oxidative stress and mobilization of metal in rats. Animals were exposed to 100 ppm arsenite as sodium arsenite in drinking water for six weeks followed by treatment with DMSA (50 mg/kg, orally), captopril (50 mg/kg, intraperitoneally) either alone or in combination, once daily for 5 consecutive days. Arsenite exposure led to a significant depletion of blood δ-aminolevulinic acid dehydratase (ALAD) activity, glutathione and platelet levels while significantly increased the level of reactive oxygen species (in RBCs). Hepatic reduced glutathione (GSH) level showed a significant decrease while, thiobarbituric acid reactive substances (TBARS) levels increased on arsenite exposure indicating arsenite induced hepatic oxidative stress. Kidney GSH, GSSG, catalase and TBARS remained unchanged on arsenite exposure. Treatment with DMSA was effective in increasing ALAD activity while, captopril was ineffective when given alone. Captopril when co-administered with DMSA also provided no additional beneficial effect on blood ALAD activity but significant brought altered platelet counts back to the normal value. In contrast, administration of captopril alone provided significant beneficial effects on hepatic oxidative stress, and in combination with DMSA provided a more pronounced recovery in the TBARS level compared to the individual effect of DMSA and captopril. Renal biochemical variables remained insensitive to arsenite and any of the treatments. Interestingly, combined administration of captopril with DMSA had a remarkable effect in depleting total arsenic concentration from blood and soft tissues. These results lead us to conclude that captopril administration during chelation treatment had some beneficial effects particularly on the protection of inhibited blood ALAD activity, and depletion of arsenic level. The study supports our earlier conclusion that a co-administration of an antioxidant is more beneficial than monotherapy with the chelating agents, in order to achieve optimal effects of chelation in arsenite toxicity.

Total arsenic concentrations in toenails quantified by two techniques provide a useful biomarker of chronic arsenic exposure in drinking water

Accurate quantitation of any contaminant of interest is critical for exposure assessment and metabolism studies that support risk assessment. A preliminary step in an arsenic exposure assessment study in Nevada quantified total arsenic (TAs) concentrations in tissues as biomarkers of exposure. Participants in this study ( n = 95 ) were at least 45 years old, had lived in the area for more than 20 years, and were exposed to a wide range of arsenic concentrations in drinking water (3–2100 ppb). Concentrations of TAs in blood, urine, and toenails determined by hydride generation-atomic fluorescence spectrometry (HG-AFS) ranged from below detection to 0.03, 0.76, and 12 ppm, respectively; TAs in blood rarely exceeded the limit of detection. For comparison, TAs in toenails determined by neutron activation analysis (NAA) ranged from below detection to 16 ppm. Significant ( P < 0.0001 ) positive regressions were seen between the TAs concentration in toenails and in drinking water (adjusted r 2 = 0.3557 HG-AFS, adjusted r 2 = 0.3922 NAA); TAs concentrations in urine were not described by drinking water As (adjusted r 2 = 0.0170 , P = 0.1369 ). Analyses of TAs in toenails by HGAFS and NAA yielded highly concordant estimates ( r = 0.7977 , P < 0.0001 ). These results suggest that toenails are a better biomarker of chronic As exposure than urine in the current study, because the sequestration of As in toenails provides an integration of exposure over time that does not occur in urine.

Therapeutic Value ofHippophae rhamnoidesL. Against Subchronic Arsenic Toxicity in Mice

The present study was planned to investigate the therapeutic efficacy of Hippophae rhamnoides L. against the toxic effects of arsenic in mice. H. rhamnoides L. is used as an herbal remedy for gastric ulcers, burns, and some skin and allergic diseases. Twenty-five Swiss albino mice were exposed to arsenic (25 ppm) in drinking water for 3 months. After 3 months different fruit extracts of H. rhamnoides L. (500 mg/kg for 10 days) were administered, the animals were sacrificed, and blood and tissues were assayed for various biochemical indicators of oxidative stress and whether arsenic was removed from tissues. Treatment with different fruit extracts of H. rhamnoides L. showed significant protection from arsenic inhibition of blood delta-aminolevulinic acid dehydratase activity and restored blood reduced glutathione levels. Other hematologic variables like white blood cell counts, hemoglobin, and hematocrit were partially protected by supplementation with a water extract of H. rhamnoides L. (HF-WRT). Significant protection was also observed in altered hepatic, renal, and brain reduced/ oxidized glutathione ratio and thiobarbituric acid-reactive substances levels. The aqueous extract of H. rhamnoides L. (HF-WRT) also provided protection against parameters indicative of liver injury such as aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase activities. There was also no effect on blood and tissue arsenic concentrations observed except some moderate depletion of blood arsenic concentrations, suggesting that the drug has no ability to chelate intracellular arsenic. It can be concluded from these results that post-treatment with an aqueous extract of H. rhamnoides L. (HF-WRT) significantly protects against arsenic-induced oxidative stress but does not chelate arsenic, suggesting it may have a beneficial role as a supplementing agent during chelation of arsenic by other means.

Arsenic bioaccumulation and species in marine polychaeta

Published whole tissue arsenic concentrations in polychaete species tissues range from 1.5–2739 µg arsenic/g dry mass. Higher mean total arsenic concentrations are found in deposit-feeding polychaetes relative to non-deposit-feeding polychaete species collected from the same locations. However, mean arsenic concentrations at some of the locations are skewed by the high arsenic concentrations of Tharyx marioni. There appears to be no direct correlation between sediment arsenic concentrations and polychaete arsenic concentrations. Arsenic bioaccumulation by polychaetes appears to be more controlled by the physiology of the polychaetes rather than exposure to arsenic via ingested material or the prevailing physiochemical conditions. Arsenic concentrations in polychaete tissues can vary greatly. Most polychaete species contain the majority of their arsenic as arsenobetaine (57–98%), with trace concentrations of inorganic arsenic (<1%) and other simple methylated species (<7.5%). However, this is not always the case, with unusually high proportions of arsenite (57%), arsenate (23%) and dimethylarsinic acid (83–87%) in some polychaete species. Arsenobetaine is probably accumulated by polychaetes via organic food sources within the sediment. The presence of relatively high proportions of phosphate arsenoriboside (up to 12%) in some opportunistic omnivorous Nereididae polychaete species may be due to ingestion of macroalgae, benthic diatoms and/or phytoplankton. Consideration of the ecology of individual polychaete species in terms of their habitat type, food preferences, physiology and exposure to arsenic species is needed for the assessment of arsenic uptake pathways and bioaccumulation of arsenic. Future research should collect a range of polychaete species from a wide variety of uncontaminated marine habitats to determine the influence of these ecological factors on total arsenic concentrations and species proportions. Copyright © 2005 John Wiley & Sons, Ltd.

Arsenic Content in Tissues of Fish from the River Elbe

âelechovska O., Z. Svobodova, T. Randak: Arsenic Content in Tissues of Fish from the River Elbe. Acta Vet. Brno 2005, 74: 419-425. The aim of the study was to evaluate arsenic content in tissues (muscle, liver, kidneys, gonads) of fish caught in selected localities along the River Elbe and its tributary the Vltava in 1999, 2002 and 2003, and in pools of the River Elbe in 2000. A total of 118 bream and 151 perch were examined by AAS. The highest muscle tissue arsenic concentrations were found in Zelain in bream in 2003 (0.17 ± 0.08 mg·kg -1 ) and in perch in 2002 (0.084 ± 0.012 mg·kg -1 ). The highest arsenic concentrations in perch were found in the kidneys, followed by the liver, milt, muscle tissue and eggs. An increase (P < 0.01) in arsenic concentrations in 2003 (after floods) compared with 2002 was found in bream muscle tissues in Zelain and in perch muscle tissues in Podoli; a decrease in arsenic concentrations was demonstrated in perch musculature in Verdek, Numaice, Hfiensko (P < 0.01) and in bream musculature in Hfiensko (P < 0.05). Arsenic contamination in the localities under study does not pose a major environmental or health risk.

Arsenic antagonism studies with monoisoamyl DMSA and zinc in male mice

Administration of zinc either alone or in combination with monoisoamyl dimercaptosuccinic acid (DMSA) during and post-arsenic exposure was investigated in male mice. The animals were administered 2 mg kg −1 arsenic as sodium arsenite, intraperitoneally, once daily for 5 days either alone or in combination with 10 mg kg −1, zinc (as zinc acetate, orally), 50 mg kg −1 monoisoamyl dimercaptosuccinic acid (MiADMSA) given orally (p.o.), 2 h after arsenic administration. Another group of arsenic treated animals was given both zinc (10 mg kg −1) and MiADMSA (50 mg kg −1, p.o.). Animals were sacrificed 24 h after the last dose. In another set of experimentation, arsenic pre-exposed mice (2 mg kg −1, i.p. for 5 days) were treated with saline, zinc, MiADMSA or zinc plus MiADMSA for next 3 days and sacrificed thereafter. Exposure to arsenic led to a significant inhibition of blood δ-aminolevulinic acid dehydratase (ALAD), depletion of glutathione (GSH) level and marginal elevations of zinc protoporphyrin (ZPP). Arsenic exposure caused a significant decrease in hepatic and renal GSH level and an increase in liver oxidized glutathione (GSSG) and liver and kidney thiobarbituric acid reactive substance (TBARS) levels. Concomitant administration of zinc with arsenic provided significant protection to blood ALAD activity while, GSH and ZPP levels remained unaltered. Co-administration of MiADMSA with arsenic significantly prevented accumulation of arsenic in blood, liver and kidney while, zinc had no effect on tissue arsenic concentration. Combined administration of zinc and MiADMSA had no major additional beneficial effects over their individual effects. Interestingly, post-arsenic exposure treatment with MiADMSA provided significant recovery in blood ALAD activity while, zinc supplementation alone had no effect. The best results however, were obtained when MiADMSA was administered along-with zinc. Most of the biochemical variables indicative of hepatic oxidative stress responded favorably to MiADMSA treatment while, zinc administration had no effect. Administration of MiADMSA significantly depleted arsenic concentration from the soft tissues while, combined zinc and MiADMSA had no additional beneficial effect over the individual effect of MiADMSA. The results thus lead us to conclude that in order to achieve best effects of chelation therapy, co-administration of zinc with chelator might be preferred. However, detailed experimental studies with variable doses and after chronic arsenic exposure are required.

Mean total arsenic concentrations in chicken 1989-2000 and estimated exposures for consumers of chicken.

The purpose of this study was to estimate mean concentrations of total arsenic in chicken liver tissue and then estimate total and inorganic arsenic ingested by humans through chicken consumption. We used national monitoring data from the Food Safety and Inspection Service National Residue Program to estimate mean arsenic concentrations for 1994-2000. Incorporating assumptions about the concentrations of arsenic in liver and muscle tissues as well as the proportions of inorganic and organic arsenic, we then applied the estimates to national chicken consumption data to calculate inorganic, organic, and total arsenic ingested by eating chicken. The mean concentration of total arsenic in young chickens was 0.39 ppm, 3- to 4-fold higher than in other poultry and meat. At mean levels of chicken consumption (60 g/person/day), people may ingest 1.38-5.24 microg/day of inorganic arsenic from chicken alone. At the 99th percentile of chicken consumption (350 g chicken/day), people may ingest 21.13-30.59 microg inorganic arsenic/day and 32.50-47.07 microg total arsenic/day from chicken. These concentrations are higher than previously recognized in chicken, which may necessitate adjustments to estimates of arsenic ingested through diet and may need to be considered when estimating overall exposure to arsenic.

Arsenic speciation in the earthwormsLumbricus rubellusandDendrodrilus rubidus

Two species of earthworm, Lumbricus rubellus Hoffmeister and Dendrodrilus rubidus (Savigny) collected from an arsenic-contaminated mine spoil site and an uncontaminated site were investigated for total tissue arsenic concentrations and for arsenic compounds by liquid chromatography-mass spectrometry (LC-MS) and liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS). For L. rubellus, whole-body total tissue arsenic concentrations were 7.0 to 17.0 mg arsenic/ kg dry weight in uncontaminated soil and 162 to 566 mg arsenic/kg dry weight in contaminated soil. For D. rubidus, whole-body tissue concentrations were 2.0 to 5.0 mg arsenic/kg dry weight and 97 to 321 mg arsenic/kg dry weight, respectively. Arsenobetaine was the only organic arsenic species detected in both species of earthworms, with the remainder of the extractable arsenic being arsenate and arsenite. There was an increase in the proportion of arsenic present as arsenobetaine in the total arsenic burden. Lumbricus rubellus and D. rubidus have similar life styles, both being surface living and litter feeding. Arsenic speciation was found to be similar in both species for both uncontaminated and contaminated sites, with dose-dependent formation of arsenobetaine. When L. rubellus and D. rabidus from contaminated sites were incubated in arsenic-free soils, the total tissue burden of arsenic diminished. Initially, L. rubellus from the tolerant populations (from the contaminated site) eliminated arsenic in the first 7 d of exposure before accumulating arsenic in tissues, whereas nontolerant populations (from the uncontaminated site) accumulated arsenic linearly. The tolerant and nontolerant L. rubellus eliminated tissue arsenic linearly over 21 d when incubated in uncontaminated soil.

Effects on levels of glutathione and some related enzymes in tissues after an acute arsenic exposure in rats and their relationship to dietary protein deficiency.

Arsenic is a potent toxin, carcinogen and modulator of antioxidant defense system. In this study, male rats of Wistar strain, maintained on either 18% or 6% protein (casein) diet, received an acute i.p. exposure to sodium arsenite (As3+) at its LD50 dose (15.86 mg/kg body weight). One hour after the arsenic exposure, glutathione (GSH) concentration was significantly depleted and lipid peroxidation was increased. A relationship between any two of tissue arsenic concentrations, GSH levels and lipid peroxidation values was observed only for liver when the proportional changes of respective parameters in either of the dietary groups of animals were compared. This suggests that, in liver, arsenic metabolism appears dependant upon the GSH concentration. Acute arsenic exposure significantly increased the glutathione peroxidase (GPx) activity in liver of both dietary groups and in kidney of only the 18% protein-fed group of animals. The glutathione-S-transferase (GST) activity significantly decreased in liver of the 18% protein-fed animals while GST increased in kidney of both the 18% and the 6% protein-fed groups. No significant change in glutathione reductase (GR) or glucose-6-phosphate dehydrogenase (G6PDH) activity was observed. In the present investigation, liver as a whole seems to be more affected in terms of GSH level and GST activity. The mode of responses of GPx and GR activities as well as the unaltered G6PDH activity might result in arsenic-induced GSH depletion and increase in lipid peroxidation. The animals of the 6% protein-fed group, appeared to be affected less in terms of tissue arsenic concentration, GSH level and GST activity. lipid peroxidation,