Concentrations of Metals in Water,Sediment, Biofilm,Benthic Macroinvertebrates,and Fish in the Boulder River Watershed,Montana, and the Role of Colloids in Metal Uptake

To characterize the partitioning of metals in a stream ecosystem, concentrations of trace metals including As, Cd, Cu, Pb, and Zn were measured in water, colloids, sediment, biofilm (also referred to as aufwuchs), macroinvertebrates, and fish collected from the Boulder River watershed, Montana. Median concentrations of Cd, Cu, and Zn in water throughout the watershed exceeded the U.S. EPA acute and chronic criteria for protection of aquatic life. Concentrations of As, Cd, Cu, Pb, and Zn in sediment were sufficient in the tributaries to cause invertebrate toxicity. The concentrations of As, Cu, Cd, Pb, and Zn in invertebrates from lower Cataract Creek (63, 339, 59, 34, and 2,410 μg/g dry wt, respectively) were greater than the concentrations in invertebrates from the Clark Fork River watershed, Montana (19, 174, 2.3, 15, and 648 μg/g, respectively), that were associated with reduced survival, growth, and health of cutthroat trout fed diets composed of those invertebrates. Colloids and biofilm seem to play a critical role in the pathway of metals into the food chain and concentrations of As, Cu, Pb, and Zn in these two components are significantly correlated. We suggest that transfer of metals associated with Fe colloids to biological components of biofilm is an important pathway where metals associated with abiotic components are first available to biotic components. The significant correlations suggest that Cd, Cu, and Zn may move independently to biota (biofilm, invertebrates, or fish tissues) from water and sediment. The possibility exists that Cd, Cu, and Zn concentrations increase in fish tissues as a result of direct contact with water and sediment and indirect exposure through the food chain. However, uptake through the food chain to fish may be more important for As. Although As concentrations in colloids and biofilm were significantly correlated with As water concentrations, As concentrations in fish tissues were not correlated with water. The pathway for Pb into biological components seems to begin with sediment because concentrations of Pb in water were not significantly correlated with any other component and because concentrations of Pb in the water were often below detection limits.     

Oxidative Stress Biomarkers in the Digestive Gland of Theba pisana Exposed to Heavy Metals

The in vivo toxic effects of sublethal treatment of 40 and 80% of 48-h LD₅₀ of topically applied trace metals [copper (Cu), lead (Pb), and zinc (Zn)] on oxidative stress biomarkers in the digestive gland of Theba pisana were examined. Oxidative individual perturbations were assessed by measuring nonenzymatic (glutathione; GSH) and enzymatic (catalase, CAT; glutathione peroxidase, GPx; and glutathione-S-transferase, GST) antioxidants in digestive gland of the snails. Lipid peroxidation (LPO) was also evaluated as a marker of cell damage. The results indicated that the copper ion was the most potent metal against this snail, followed by zinc and lead, for which the corresponding LD₅₀ values were 37.88, 261.72, and 652.55 μg/snail, respectively. The no-observed effect concentration (NOEC) values for Cu, Zn, and Pb were 10, 50, and 500 μg/snail, respectively, and the corresponding lowest-observed effect concentration (LOEC) values were 50, 100, and 1000 μg/snail. All trace metals resulted in a significant increase in the level of LPO, whereas a significant decline in the content of GSH was observed when compared with untreated controls. Treatment with both sublethal doses of the metals caused significant increase in CAT activity, except in the case of 40% LD₅₀ Zn and 80% LD₅₀ Cu, which exhibited no alteration in CAT when compared to control animals. GPx was significantly increased in snails exposed to 40% LD₅₀ Cu and Pb as well as 80% LD₅₀ Cu. However, an opposite effect was observed in snails exposed to 80% LD₅₀ Pb and in either 40 or 80% LD₅₀ of Zn-intoxicated animals. Treatment with Pb at two sublethal doses significantly increased GST activity, whereas treatment the animal with Cu caused significant inhibition in this enzyme. Snails exposed to 40% LD₅₀ Zn showed significant enhancement of GST, whereas snails exposed to 80% LD₅₀ showed ignificantly reduced GST activity. Biphasic responses were observed for CAT, GPx, and GST activities in snails exposed to Cu, Pb, and Zn, respectively. This study suggests that upregulation of the antioxidant enzyme activities, elevation of LPO, and the reduction in GSH content is related to oxidative stress in this species that could be useful as biomarkers for the evaluation of contaminated terrestrial ecosystems.     

Dose-dependent effects of dietary Pb and Zn on feeding and growth rates of the landsnail Helix engaddensis

Dose-dependent effects of dietary lead and zinc on feeding and growth rates of adult Helix engaddensis snails were studied over a 1-month period followed by a 2-week recovery period. Snails were fed on an artificial diet containing the following lead or zinc concentrations= 0, 20, 100, 500, 2500, and 12,500 microg/g dry food. At the end of the 6 weeks, mortality rate among snails fed on Pb-contaminated diet was 18.3% (11/60) and the respective value for Zn-contaminated diet was 50% (30/60). Both metals significantly reduced growth and feeding rates. Snails were found to be sensitive to zinc but tolerant to lead. During the recovery period, snails fed on Zn-contaminated diet failed completely to feed or grow normally, whereas snails fed on Pb-contaminated diet showed signs of slow improvement in terms of feeding and growth rates. The NOEC and LOEC for lead were 100 and 500 microg/g (-1), respectively, while the respective concentrations for zinc were 20 and 100 microg/g (-1).     

Contamination of Metals in Tissues of <Emphasis Type="Italic">Ctenopharyngodon idella</Emphasis> and <Emphasis Type="Italic">Perca fluviatilis</Emphasis>, from Anzali Wetland,Iran

The objective of the present study was to investigate the levels of metals (Cd, Cu, Zn, Pb and Cr) in muscle, gill, liver, kidney and intestine of two freshwater fish, Ctenopharyngodon idella and Perca fluviatilis, in Anzali Wetland, Iran. The concentrations were different between the fish species as well as among the tissues of fish. Results showed that the metal concentrations in both fish species were in descending order of Zn > Cu > Pb > Cr > Cd. Results also showed that the Cd, Cu, Zn, and Pb concentrations in the muscle of both fish from Anzali Wetland are below levels of concern for human consumption.     

Decennary Variations of Dissolved Heavy Metals in Seawater of Bohai Bay,North China

Characteristics of the spatial and temporal distributions of selected dissolved heavy metals (Cu, Zn, Pb, Hg and Cd) in Bohai Bay, north China was investigated. Water samples from 22 sites were collected and analyzed for the selected metals with atomic absorption spectrometry from the year of 1996 to 2005. Relatively high concentrations of Cu, Zn, Pb and Hg were detected, with maximum concentrations in the 10-year period of 16.30, 422.00, 40.40, 0.23 μg/L respectively. The concentrations of Cd in all samples were quite low, with maximum level of 0.89 μg/L. The spatial distribution of dissolved Cu, Zn and Pb was analogous, where their average concentrations generally descended from the coastline to the central areas of the bay. Differently, for Hg and Cd, relatively high concentrations occurred not only in inshore but also in offshore areas. Measured data of heavy metals were compared with sea water quality standard of China (SWQSC). Cd concentrations in all samples were below SWQSC Grade-I. The percentages of Cu, Zn, Pb, and Hg at Grade-III levels in Bohai Bay were 2.67%, 30.00%, 30.43% and 0.36%, respectively, suggesting the severe contamination of Zn and Pb in this area. Terrestrial inputs via different rivers and sewages may be the important source for the heavy metals contamination.     

Lead and Copper in Pigeons (<Emphasis Type="Italic">Columbia livia</Emphasis>) Exposed to a Small Arms–Range Soil

Small arms–range (SAR) soils can be contaminated with metals from spent copper (Cu)-jacketed bullets. Avian species are particularly at risk because they are exposed to lead (Pb) through ingestion of grit, soil intake from preening, or ingestion of contaminated food near ranges. Examination of the effects of Pb on birds at ranges have mainly focused on intake and toxicity of Pb shot pellets or fragments; however, Pb in soils may be an important pathway of exposure. To evaluate the uptake and effects of Pb from an actual range, the soil fraction (<250 μm) from a contaminated SAR soil was used to dose pigeons (Columbia livia) for 14 days at low (2700 μg Pb and 215 μg Cu/d) and high (5400 μg Pb and 430 μg Cu/d) doses. At the end of the study, blood Pb and erythrocyte protoporphyrin were determined, and tissues were analyzed for Pb and Cu. Results showed that Pb was absorbed in a dose–response manner in blood, tissues, and feathers, and erythrocyte protoporphyrin, a biomarker of early Pb effect, was increased at blood Pb levels >50 μg/dL. Four tissues showed differential retention of Pb, with kidney having the highest concentration followed by liver, brain, and heart, whereas Cu levels were not changed. To examine possible interactions with other metals, amendments of either Cu or tungstate were made to the soil sample. Although these amendments seemed to decrease the absorption of Pb, the results were ambiguous compared with sodium chloride controls. Overall, this study showed that intake of SAR soils contaminated with Pb and Cu causes an increase in Pb body burdens in birds and that the response can be modulated by amending soils with salts of metals.     

Effects of dietary Cd and Cu on feeding and growth rates of the landsnail Helix engaddensis

Effects of dietary cadmium and copper on feeding and growth rates of adult Helix engaddensis snails were studied for a 1-month period. The concentrations of cadmium were 0, 50, 100, 200, 400, and 800 microg Cd/g dry food, while those of copper were 0, 4, 20, 100, 500, and 2500 microg Cu/g dry food. Both metals inhibited feeding and growth rates significantly after 1 week and 3 weeks of exposure to Cd and Cu, respectively. Inhibition caused by Cd was found to be irreversible, which indicates toxicity, while that of Cu was reversible, indicating starvation because snails identified and refused to consume contaminated food. After 4 weeks of exposure, the NOEC of Cd was 50 microg/g and the LOEC was 100 microg/g, while those for Cu were 20 and 100 microg/g, respectively. EC50,75,90,100 (growth and feeding) values were calculated, and indicated that H. engaddensis snails are suitable for short-term toxicity bioassays.     

Effects of Sublethal Chronic Copper Exposure on the Growth and Reproductive Success of the Florida Apple Snail (Pomacea paludosa)

Florida apple snails (Pomacea paludosa) were exposed to three concentrations of copper (Cu), in water (8 μg/L, 16 μg/L, 24 μg/L), for one generation to examine uptake and the effects on survival, growth, and reproduction of the F₀ generation and survival, growth, and whole body Cu of the F₁ generation. During a 9-month Cu exposure, apple snails exposed to 8–16 μg/L Cu had high Cu accumulation (whole body, foot, viscera, and shell) and significantly reduced clutch production (8–16 μg/L) and egg hatching (16 μg/L). Apple snails exposed to the 24 μg/L Cu had low survival and the treatment was therefore terminated. Concentrations of minerals (Na⁺, K⁺, Mg²⁺, Ca²⁺) in tissues were maintained regardless of Cu exposure, but the distribution of Cu in the body of snails differed, depending on exposure concentrations. Higher exposure concentrations resulted in a greater percentage of Cu accumulated in the viscera of the snail. Copper exposure to the F₀ generation did not affect the survival, growth, or whole body Cu concentrations in the F₁ generation. These finding are significant, given the importance of the Florida apple snail in the Everglades food chain. Changes in the abundance of apple snail populations, as a result of Cu exposure, could ultimately affect foraging success of predators.     

Growth-Related Changes in Heavy Metal Accumulation in Green Turtle (Chelonia mydas) from Yaeyama Islands, Okinawa, Japan

Concentrations of nine heavy metals (Fe, Mn, Zn, Cu, Pb, Ni, Cd, Co, and Hg) were determined in liver, kidney, and muscle of 50 green turtles (Chelonia mydas) collected from Yaeyama Islands, Okinawa, Japan, to elucidate growth-related changes in heavy metal accumulation during different growth stage. Considerably high Cu concentrations were found in the liver of smaller turtles. Mean hepatic concentration of Cu was 50.2 μg/g wet weight which varied widely (4.27–113 μg/g wet weight). Cadmium concentrations decreased with increasing the carapace length. The juvenile green turtles in the pelagic ocean are likely feed on zooplankton, while adult coastal inhabiting green turtles mainly feed on sea grasses and seaweeds. Concentrations of Cd in sea plants are lower than those in zooplankton. The specific accumulation of Cd found in the green turtle seems to be attributable to their feeding habit, which is a shift from carnivore to herbivore at different growth stages. Received: 13 September 1999/Accepted: 29 March 2000     

Bulk and Bioavailable Heavy Metals (Cd,Cu, Pb,and Zn) in Surface Sediments from Mazatlán Harbor (SE Gulf of California)

This work evaluates current metal concentrations (Cd, Cu, Pb and Zn) and the operational bio-available chemical extraction fraction in surface sediments in Mazatlán Harbor in Northwest México. Sediment samples were also analyzed for organic carbon, carbonates and particle size. Ranges of bulk metal were as follows: Cd from 3.1 to 3.3 μg/g, Cu from 31.9 to 44.9 μg/g, Pb from 49.6 to 54.0 μg/g, and Zn from 217.8 to 323.5 μg/g. In terms of biological effects, metals concentrations in the sediments lie between the low and median ranges of the mean quality guideline criteria. Comparatively, the metals concentrations increased from 1983 to 1994 and then for 2006, except Pb and Cd that decreased in the last period of time. The bio-available fraction of metals increased from 1983 to 1994, but only bio-available Cu increased from 1994 to 2006, due to mobilization of this metal from the organic matter–sulfide phase.     

Metals in Water from the River Nile Tributaries in Egypt

The objective of this study was to evaluate the levels of Zn, Cu, Pb, Fe and Cd metals in water samples collected from different tributaries of the Nile River in Egypt. Samples were taken from El-Sarsawia, El-Bagoria, Bahr Shebin canals, in addition to three drainage canal sites El-Embaby, El-Menofi and Miet-Rabiha drain. According to the data, Fe has the highest concentration, followed by Pb, Zn, Cd and Cu. The mean Pb concentration ranged from 8.678 to 21.948 μg/L, in water samples collected from El-Sarsawia canal and El-Embaby drain, respectively. The Cu and Cd mean concentrations ranged from 0.67 and 0.500 to 4.908 and 5.650 μg/L, respectively, in water samples collected from Bahr-Shebin canal and El-Embaby drain, respectively. The water samples from all location sites are polluted by Pb according to EPA. Fe and Cu values are within the allowable limits.     

Seasonal variability in cadmium, lead, copper, zinc and iron concentrations in the three major fish species, Oreochromis niloticus, Lates niloticus and Rastrineobola argentea in Winam Gulf, Lake Victoria: impact of wash-off into the lake

Trace metals Cadmium (Cd), Lead (Pb), Copper (Cu), Zinc (Zn) and Iron (Fe) were analyzed in edible portions of three main finfish species namely Lates niloticus, Oreochromis niloticus and Rastrineobola argentea sampled from various beaches of Winam Gulf, Lake Victoria, Kenya, in order to determine any seasonal and site variations and the results showed significantly (p < 0.05) higher mean concentrations of Cd, Cu, Zn and Fe during the wet season compared to the dry season for all the three species indicating the impact of wash-off into the lake during the rainy periods. The overall mean concentrations of the heavy metals (in μg/g dry weight) in all combined samples ranged from 0.17–0.40 (Cd), 0.47–2.53 (Pb), 2.13–8.74 (Cu), 28.9–409.3 (Zn) and 31.4–208.1 (Fe), respectively. It was found that consumption of Rastrineobola argentea can be a significant source of heavy metals especially Zn, to humans, compared with Lates niloticus and Oreochromis niloticus, if only the muscle parts of the latter two are consumed.     

Cadmium, Copper, Lead and Zinc Contents of the Mangrove Oyster, Crassostrea corteziensis, of Seven Coastal Lagoons of NW Mexico

The ranges of concentrations of Cd, Cu, Pb and Zn of the soft tissues of C. corteziensis collected in seven coastal lagoons of NW Mexico were 1.55–7.45, 17.50–166.36, 4.13–9.49 and 245.34–2,304.12 μg/g (dry weight), respectively. Their distributions were not consistent and there were no seasonal trends, indicating different point sources of the metals in each lagoon. The mean Cd and Pb concentrations were 5.34 and 6.30 μg/g (dry weight), which are higher than the values indicative of polluted areas. Our data indicate that only the levels of Cd are a possible health risk in six of these lagoons, and only in the case of regular local consumers. In one, Cu and Zn reach levels of concern.     

A Preliminary Study of the Distribution of Selected Trace Metals in the Besut River Basin,Terengganu, Malaysia

This paper presents a preliminary result carried out in the Besut River basin, Terengganu, Malaysia to determine the selected trace metal concentrations. Concentrations of dissolved Pb, Cu, and Fe during the present study were in the range of 3.3–8.3 μg/L Pb, 0.1–0.3 μg/L Cu, and 1.1–12.3 μg/L Fe. For the particulate fraction concentrations of Pb, Cu, and Fe ranged from 1.0 to 3.6 μg/L, 0.3 to 2.8 μg/L, and 114 to 1,537 μg/L, respectively. The concentrations of metals in this study area, in general, were lower than those reported for other study areas. Higher metal concentrations measured in the wet monsoon season suggest that the input was mainly due to terrestrial runoff.     

Levels of Toxic Metals in Multisectoral Samples from Winam Gulf of Lake Victoria

In this study, the distribution and sources of inputs of trace metals including Cd, Cu, Zn and Pb from various sources as well as Fe which is widely used in the construction industry, into Winam Gulf of Lake Victoria were investigated. The sampling sites were located up streams and down streams of four rivers (Sio, Nyamasaria, Nyando and Sondu-Miriu), in four beaches along the lake (Port Victoria, Kisumu Car Wash, Dunga and Hippo point beaches) and in three estates (Nyamasaria, Migosi and Nyawita) in Kisumu city, covering potential agrochemical and industrial sources and drinking water points, respectively. The concentrations (in μg/L) of trace metals analysed in the lake and river waters ranged from <1.79 (Cd), <3.83 (Pb), <1.53–3.86 (Cu), 4.37–11.6 (Zn), 11.8–2,440 (Fe). The sediment concentrations (in μg/kg × 10³) ranged from 0.19 to 1.91 (Cd), 6.86–138 (Pb), 18–100 (Cu), 36.2–443 (Zn) and 960–73,200 (Fe), with highest concentrations of all metals being recorded at Kisumu Car Wash area. The study confirmed that the concentrations of the metals accumulate downstream in the rivers both in water and sediment and these rivers are major sources of the heavy metal load into Winam Gulf of Lake Victoria.     

Dietary Pb Accumulation in Juvenile Freshwater Rainbow Trout (Oncorhynchus mykiss)

Three different diets amended with lead (Pb) nitrate Pb(NO₃)₂ (7, 77, and 520 μg Pb/g dry weight) and a Pb-free control diet (0.06 μg Pb/g dry weight) were fed to juvenile freshwater rainbow trout for 21 days. Accounting for measured food consumption, the calculated doses per fish were 0.02, 3.7, 39.6, and 221.5 μg/day, for the control, low, intermediate, and high Pb treatments, respectively. The patterns of Pb accumulation over time were determined in various tissues (gills, liver, kidney, intestine, carcass), red blood cells (RBC), and plasma, as well as feeding, growth, hematological, and ionoregulatory parameters. Pb accumulation occurred in a dose-dependent manner in all tissues except the plasma, where accumulation was minimal. Overall, when fed the highest Pb diet, the intestine exhibited the greatest Pb burden (17.8 μg Pb/g tissue wet weight), with high concentrations also found in the kidney (2.4 μg Pb/g tissue wet weight) and liver (1.9 μg Pb/g) at the highest dietary Pb treatment by day 21. The RBCs accumulated a substantial amount of Pb (1.5 μg Pb/g) when compared to the plasma (0.012 μg Pb/g) in the high treatment group. The percentage of Pb retained in the fish decreased with increasing dietary Pb concentrations. Growth, survival, plasma protein, and hematocrit were not significantly affected by dietary Pb. Plasma Ca²⁺ levels decreased at the beginning of the experiment, whereas Mg²⁺ levels decreased during the middle of the experiment in both the intermediate and high dietary treatments. Both the Ca²⁺ and Mg²⁺ levels stabilized by day 21. Branchial Ca²⁺ and Na⁺ influx rates were not affected by dietary Pb, except on day 8 where Na⁺ influx rates were significantly elevated. The results of this study show that Pb does accumulate internally from the diet when present at levels within the range reported in contaminated benthic invertebrates in nature. We further identify the intestine as a potential target site of chronic toxicity of Pb via the diet, and RBCs as a reservoir of dietary Pb.     

Distribution patterns of metals contamination in sediments based on type regional development on the intertidal coastal zones of the Persian Gulf, Iran

This study was performed to determine the variation of metals concentrations (Pb, Cd, Zn, and Cu) in surface sediments based on type region development from ten sites on the intertidal coastal zone of the Persian Gulf, Iran. The metals concentrations in surface sediments varied from 0.86 to 180.78 μg g⁻¹ for Pb, 0.61 to 6.48 μg g⁻¹ for Cd, 5.99 to 44.42 μg g⁻¹ for Zn, and 3.01 to 43.33 μg g⁻¹ for Cu. The quality of the sediments was evaluated based on sediment quality guidelines (effects range-low (ERL) and effects range-medium (ERM) indexes. Biological effects criteria suggest that metals concentrations in sediments were lower than ERM for all sites, but for some sites metals concentrations in sediments were higher than ERL. The present results support the concept that human activities in each region could be a major source of metals pollution input in the aquatic environment.     

Distribution of Toxic Metals in Organs of Local Cattle, Sheep, Goat and Poultry from the West Bank, Palestinian Authority

Graphite furnace atomic absorption spectrophotometry was used to measure the concentrations of Cu, Cd, Pb, and Zn in muscles and internal organs (liver, kidneys, heart, and lungs) of cattle, sheep goat and poultry sampled from local markets in the West Bank, Palestinian Authority. Mean levels of metals (dry weight basis) during this study were as follows: Cd: 0.34–0.57 μg/g, Pb: 0.2–4.7 μg/g, Cr: 0.44–3.62 μg/g and Cu: 1.03–217.9 μg/g. Muscles and internal organs of each species were found to have statistically different metal levels. Generally, livers and kidneys were found to have the highest levels of metals and muscles the lowest levels. When compared to each other, the four animal groups either did not show any significant differences or no clear trends. Compared to results reported in the literature, our results were comparable to or less than most of the studies reported from clean sites in different countries.     

Heavy Metal Content of Potato Chips and Biscuits from Nagpur City, India

Heavy metals composition of foods is of immense interest because of its essential or toxic nature. In view of this, we determined concentrations of select heavy metals from food items such as, potato chips and biscuits that were obtained from Nagpur City, India. The present study revealed preferred digestion method for different heavy metal recovery. The accumulation trend for Potato chips was in following order Fe > Al > Zn > Ni > Cu > Mn > Co > Cr > Pb and Cd, while for Biscuits it was Al > Fe > Zn > Ni > Mn > Co > Cr > Pb > Cu and Cd.     

Toxicity of Metals to the Bivalve Tellina deltoidalis and Relationships Between Metal Bioaccumulation and Metal Partitioning Between Seawater and Marine Sediments

The Australian benthic bivalve Tellina deltoidalis tolerates a wide range of sediment and water conditions, is easy to handle in the laboratory, and is a useful species for undertaking whole-sediment toxicity tests. The sensitivity of T. deltoidalis to metals was investigated in 10-day metal-spiked sediment exposures for Cd, Cu, Ni, Pb, and Zn and in water-only exposures for Cu and Zn. The survival of T. deltoidalis in 10-day exposures to metal-spiked sediments was 88–100% for Cd, Ni, Pb, and Zn concentrations of 75, 420, 1,000, and 4,000 mg/kg, respectively. The 4-day LC₅₀s for dissolved Cu and Zn were 0.18 and 13 mg/L, respectively. The 8-day LC₅₀ for Cu was 31 (24–34) μg/L. Cu and Zn concentrations in the tissues of T. deltoidalis increase linearly with increasing dissolved exposure concentration. In the Cu-spiked sediment and water exposures, the survival was negatively correlated with the Cu concentration in both the overlying water and in the tissues of T. deltoidalis. In contrast, particulate Cu concentrations were found to be a poor predictor of Cu bioaccumulation and toxicity for Cu-spiked sediments.