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Archives of Environmental Contamination and Toxicology (v.56, #3)

Influence of Mercury Speciation and Fractionation on Bioaccessibility in Soils by Gerald J. Zagury; Christophe Bedeaux; Bruno Welfringer (pp. 371-379).

Ingestion of contaminated soils by children during hand-to-mouth activities can be a significant exposure pathway to toxic chemicals. Bioaccessibility, which corresponds to the fraction of an ingested contaminant dissolved in the gastrointestinal tract and potentially available for absorption, can be determined by in vitro extractions and gives a conservative value of relative oral bioavailability. The goal of this study was to investigate the validity of the CDM in vitro extraction protocol, developed by Camp Dresser and Mc Kee, by assessing the influence of soil properties and Hg fractionation on bioaccessibility. Mercury bioaccessibility was determined in two pure mercury compounds, two reference materials (a soil and a sediment), and three field-collected contaminated soils. Soils and reference materials were characterized and a sequential extraction procedure was applied to the samples. Bioaccessibility of HgCl₂ was 99.8% in the gastric phase and 88.6% in the intestinal phase, whereas bioaccessibility of HgS was lower than 0.01%. In field-collected soils A, B, M, and, in ERM-CC580, mercury bioaccessibility was lower than 3.2% (below detection). In contrast, CRM 025–050 had a high Hg bioaccessibility (44.3% for gastric phase and 34.7% for intestinal phase). Gastric and intestinal bioaccessibility values were positively correlated with sulfate content in soils (r = 0.99, p < 0.001, for both gastric and intestinal bioaccessibility). In field-collected soils and ERM-CC580, the residual fraction represented near 100% of the mercury recovered, with less than 2% of mercury being in the water-soluble (F1) and CaCl₂-exchangeable (F2) fractions. In contrast, 46% of mercury in the reference material CRM 025-050 was extracted in the CaCl₂-exchangeable fraction. Results of the sequential extractions were in agreement with bioaccessibility values, with the sum of the water-soluble and CaCl₂-exchangeable fractions (F1 + F2) highly correlated with intestinal bioaccessibility values (r = 0.99, p < 0.001). Hence, the sequential extraction procedure used in this study could be a simple means to help validate mercury bioaccessibility.

Respiratory Irritants in Australian Bushfire Smoke: Air Toxics Sampling in a Smoke Chamber and During Prescribed Burns by Annemarie J. B. M. De Vos; Fabienne Reisen; Angus Cook; Brian Devine; Philip Weinstein (pp. 380-388).

Bushfire smoke contains an array of organic and inorganic compounds, including respirable and inspirable particles, aldehydes, and carbon monoxide. These compounds have been found to be a health hazard for firefighters in the United States. Despite the high frequency of bushfires in Australia, analyses of bushfire smoke components are scarce. As part of an occupational health study investigating the respiratory health effects of bushfire smoke in firefighters, air toxics sampling was undertaken in a smoke chamber and during prescribed burns. Levels of formaldehyde and acrolein were demonstrated at respectively 60% and 80% of the Short Term Exposure Limit in the smoke chamber. Carbon monoxide levels exceeded the peak limit of 400 ppm significantly. Although concentrations were lower during the prescribed burns, the study shows that Australian bushfire smoke contains air toxics of concern and provides justification for further research into the levels of air toxics measured at bushfires and the associated health impacts.

Toxicity Testing of Sediment Collected in the Vicinity of Effluent Discharges from Seafood Processing Plants in the Maritimes by Benoit A. Lalonde; Paula Jackman; Ken Doe; Christine Garron; Jamie Aubé (pp. 389-396).

There are over 1100 fish-processing plants in Canada and the majority of them discharge untreated effluents directly to marine or estuarine receiving environments. The purpose of this study was to evaluate chemical and toxicological characteristics of sediments near fish-processing plant effluent discharges to assess potential impacts of seafood-processing effluents on receiving environments. Eighteen sediment samples were collected near effluent discharges of six seafood-processing plant outfalls in New Brunswick, Canada in the winter of 2006. Ammonia levels ranged from <0.2 to 3480 μg/g, sulfide levels ranged from <0.4 to 6970 μg/g, and redox ranged from −255 to 443 mV. Only one sample had a Microtox™ Solid-Phase Test IC₅₀ value below 1000 mg/kg, whereas three samples caused greater than 30% reduction to amphipod survival. Redox, sulfide, and ammonia concentrations were all found to be significantly related to both Eohaustorius estuarius survival and Microto (Vibrio fischeri) IC₅₀. An increase in sulfide (R ² = 0.584; 0.750) and ammonia (R ² = 0.478; 0.552) and a decrease in redox (R ² = 0.485; 0.651) were associated with an increase in toxicity to E. estuarius and Microtox, respectively. The highest toxicity to both test organisms, and the most contaminated sediments based on physical/chemical characteristics measured, was observed in samples from Blacks Harbour.

Treated Wastewater Effluent Reduces Sperm Motility Along an Osmolality Gradient by H. L. Schoenfuss; J. T. Levitt; R. Rai; M. L. Julius; D. Martinovic (pp. 397-407).

Many toxic effects of treated wastewater effluent on organismal and reproductive health have been documented. However, the physicochemical environment of treated wastewater effluent frequently differs considerably from that of its receiving waters and may affect organismal function independently of toxic effects. Teleost sperm, for example, may be affected by the higher osmolality of treated wastewater, as this sperm is activated for a brief period of time following ejaculation due to the sudden decrease in osmolality of its surrounding environment. In this study, we examined the effects of treated wastewater effluent on sperm motility to test the hypothesis that the higher osmolality of effluent compared to river water will adversely affect sperm activation in a concentration-dependent relationship. Treated wastewater effluent was collected on 5 days from the outflow of the Metropolitan Wastewater Treatment Plant, St. Paul, Minnesota, and from an upstream site on the Mississippi River. Milt aliquots collected from goldfish were diluted in an isotonic extender solution and subsequently activated in either deionized water, 100%, 50%, or 10% effluent, a synthetic ion mixture, or river water. Sperm motility and velocity were assessed at 15-s intervals for 1 min using a computer assisted sperm analyzer. Significant differences in performance parameters were found only at 15 s, with sperm motility and velocity declining rapidly at later sampling times. Predictably, deionized water resulted in the greatest activation of sperm motility, while motility exhibited a concentration-dependent decline in 10%, 50%, and 100% treated wastewater effluent. Interestingly, Mississippi River water and a synthetic ion mixture with an osmolality comparable to 50% effluent both resulted in the least amount of sperm activation. However, sperm activation in river water varied between collection days during the study. River water and 100% effluent both had low sperm activation characteristics despite a 10-fold difference in osmolality between these two treatments (1 and 10 mOsmol kg⁻¹, respectively). Results of this study indicate a concentration-dependent decrease in sperm motility in treated wastewater effluent as well as significant fluctuations of sperm activation in Mississippi River water. This study illustrates the complexity of assessing the effects of treated wastewater effluents and the difficulty of determining appropriate reference sites for such studies.

Presence and Fate of Carbamazepine, Oxcarbazepine, and Seven of Their Metabolites at Wastewater Treatment Plants by Marie Leclercq; Olivier Mathieu; Elena Gomez; Claude Casellas; Hélène Fenet; Dominique Hillaire-Buys (pp. 408-415).

Many pharmaceuticals are excreted in wastewater as parent substances or metabolites subsequent to therapeutic or diagnostic application in medical care. This includes the antiepileptic carbamazepine, which is not removed during conventional wastewater treatment and was found to be ubiquitous in the aquatic environment. Some carbamazepine metabolites have also been found in treated wastewater, but only five of them have been studied to date. However, at least 30 carbamazepine metabolites have been identified in humans, including some pharmacologically active or genotoxic compounds. Oxcarbazepine, an antiepileptic which is increasingly used, generates metabolites common to those of carbamazepine. The present work focuses on the presence of carbamazepine, oxcarbazepine, and seven of their metabolites (carbamazepine-10,11-epoxide, 10-hydroxy-10,11-dihydrocarbamazepine, 10,11-dihydro-10,11-trans-dihydroxycarbamazepine, 2-hydroxy-carbamazepine, iminostilbene, acridine, and acridone) at three different treatment plants (conventional activated sludge, trickling filter, and stabilization ponds) selected in France. The main aim of this work was to identify selected compounds in wastewater after therapeutic use and to measure concentrations in influents and effluents at the three wastewater treatment plants. Except for iminostilbene, all of these compounds were detected in wastewater. The metabolite common to carbamazepine and oxcarbazepine, i.e., 10,11-dihydro-10,11-trans-dihydroxycarbamazepine, was detected at a higher concentration than the parent substances in wastewater. The presence of parent molecules was noted in inlet and outlet water samples. Carbamazepine, as expected, was not removed by conventional activated sludge treatment. Nevertheless, in a wastewater treatment plant with a 78-day hydraulic retention time, a 73% decrease in carbamazepine concentration was observed. For the first time, oxcarbazepine was found in environmental samples. A decrease in oxcarbazepine concentrations was observed at the three sewage treatment plants, with removal ranging from 24 to 73%. No metabolite removal was observed after activated sludge treatment. In the two other sewage treatments plants, the fate of the metabolites differed. The concentration of some metabolites, e.g., 10,11-dihydro-10,11-trans-dihydroxycarbamazepine and acridine, increased, possibly via different processes such as cleavage of glucuronide conjugates or biotic and abiotic degradation of parent compounds. The behavior of the studied substances is discussed in terms of the treatment process and hydraulic retention time.

Identification of a Potential Toxic Hot Spot Associated with AVS Spatial and Seasonal Variation by O. Campana; A. Rodríguez; J. Blasco (pp. 416-425).

In risk assessment of aquatic sediments, much attention is paid to the difference between acid-volatile sulfide (AVS) and simultaneously extracted metals (SEMs) as indicators of metal availability. Ten representative sampling sites were selected along the estuary of the Guadalete River. Surficial sediments were sampled in winter and summer to better understand SEM and AVS spatial and seasonal distributions and to establish priority risk areas. Total SEM concentration (ΣSEM) ranged from 0.3 to 4.7 μmol g⁻¹. It was not significantly different between seasons, however, it showed a significant difference between sampling stations. AVS concentrations were much more variable, showing significant spatial and temporal variations. The values ranged from 0.8 to 22.4 μmol g⁻¹. The SEM/AVS ratio was found to be <1 at all except one station located near the mouth of the estuary. The results provided information on a potential pollution source near the mouth of the estuary, probably associated with vessel-related activities carried out in a local harbor area located near the station.

Responses of a Free-Living Marine Nematode Community to Mercury Contamination: Results from Microcosm Experiments by M. Hermi; E. Mahmoudi; H. Beyrem; P. Aïssa; N. Essid (pp. 426-433).

A microcosm experiment was used to examine the effects of mercury contamination on a free-living nematode community in a Tunisian lagoon. Sediments were contaminated with three mercury concentrations (low, 0.084 ppm; medium, 0.167 ppm; and high, 0.334 ppm), and effects were examined after 60 days. Results from multiple-comparison tests showed significant differences between nematode assemblages from undisturbed control and those from mercury treatments. Most univariate measures decreased significantly with increasing level of Hg contamination. Results from multivariate analyses of the species abundance data demonstrated that responses of nematode species to mercury contamination were varied: Araeolaimus bioculatus was eliminated at all the mercury doses tested and seemed to be an intolerant species to mercury contamination; Marylynnia stekhoveni increased at low and medium concentrations and appeared to be an “opportunistic” species at these doses, whereas Prochromadorella neapolitana, which increased at all doses tested (0.084, 0.167, and 0.334 ppm), seemed to be a “mercury-resistant” species.

Effects of Phenanthrene- and Metal-Contaminated Sediment on the Feeding Activity of the Harpacticoid Copepod, Schizopera knabeni by Soraya J. Silva; Kevin R. Carman; John W. Fleeger; Tonya Marshall; Sidney J. Marlborough (pp. 434-441).

The effects of sediments contaminated with sublethal concentrations of phenanthrene (PAH) and metals (Cd, Hg, Pb) were evaluated in relation to their influence on the feeding activity of a harpacticoid copepod, Schizopera knabeni. A metal mixture (at the ratio of 5Pb:3Cd:2Hg) and Cd alone reduced grazing rates of S. knabeni feeding on ¹⁴C-labeled microalgae. Cadmium alone and Cd combined with phenanthrene significantly decreased grazing rates of S. knabeni at Cd concentrations above 49 mg kg⁻¹ dry sediment. No grazing was observed in 98, 106, or 157 mg kg⁻¹ dry sediment Cd alone or in sediment contaminated with phenanthrene (98 mg kg⁻¹ dry sediment) combined with Cd at these concentrations. Phenanthrene alone also caused a significant decrease (55%) in S. knabeni grazing rates. Feeding ceased above 344 mg kg⁻¹ dry sediment of the metal mixture alone and combined with phenanthrene. Results were consistent with an independent effect on feeding when Cd and phenanthrene were combined. When other metals were added (Pb and Hg) to the mixture, results were consistent with an additive influence on feeding rate. Because the underlying mechanisms of toxicity for metals and PAH are probably different, our observations suggest that reductions in grazing probably did not directly contribute to the lethal effects of phenanthrene or metals. The absence of interactive effects on feeding suggests that metal-PAH interactive effects on lethality have a different underlying mechanism and that reductions in grazing probably did not directly contribute to the lethality effects of phenanthrene or metals in S. knabeni.

Effect of Sequential Isoproturon Pulse Exposure on Scenedesmus vacuolatus by Nathalie Vallotton; Rik Ilda Lambertus Eggen; Nathalie Chèvre (pp. 442-449).

Aquatic organisms are typically exposed to fluctuating concentrations of herbicides in streams. To assess the effects on algae of repeated peak exposure to the herbicide isoproturon, we subjected the alga Scenedesmus vacuolatus to two sequential pulse exposure scenarios. Effects on growth and on the inhibition of the effective quantum yield of photosystem II (PSII) were measured. In the first scenario, algae were exposed to short, 5-h pulses at high isoproturon concentrations (400 and 1000 μg/l), each followed by a recovery period of 18 h, while the second scenario consisted of 22.5-h pulses at lower concentrations (60 and 120 μg/l), alternating with short recovery periods (1.5 h). In addition, any changes in the sensitivity of the algae to isoproturon following sequential pulses were examined by determining the growth rate-EC₅₀ prior to and following exposure. In both exposure scenarios, we found that algal growth and its effective quantum yield were systematically inhibited during the exposures and that these effects were reversible. Sequential pulses to isoproturon could be considered a sequence of independent events. Nevertheless, a consequence of inhibited growth during the repeated exposures is the cumulative decrease in biomass production. Furthermore, in the second scenario, when the sequence of long pulses began to approach a scenario of continuous exposure, a slight increase in the tolerance of the algae to isoproturon was observed. These findings indicated that sequential pulses do affect algae during each pulse exposure, even if algae recover between the exposures. These observations could support an improved risk assessment of fluctuating exposures to reversibly acting herbicides.

Effects of Sublethal Chronic Copper Exposure on the Growth and Reproductive Success of the Florida Apple Snail (Pomacea paludosa) by Emily C. Rogevich; Tham C. Hoang; Gary M. Rand (pp. 450-458).

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.

Effects of Copper in Flooded Florida Agricultural Soils on Hyalella azteca by Tham C. Hoang; Lance J. Schuler; Gary M. Rand (pp. 459-467).

This study examined the uptake and effects of copper (Cu) from flooded agricultural soils to epibenthic amphipods (Hyalella azteca) using 10-day sediment toxicity tests. Soils were collected from 10 citrus agricultural sites in South Florida. One sediment toxicity test was conducted with one flooding of the 10 soils, and based on the results of this test a second sediment toxicity test was conducted with 4 of the soils, after four 14-day flooding and four 14-day drying intervals over 4 months. Sediment toxicity tests were conducted under flow-through conditions using U.S. EPA methodology. Effects on survival, dry weight, and whole-body Cu concentrations of H. azteca were determined. Cu concentrations in overlying water and sediment of both sediment toxicity tests exceeded regulatory criteria for aquatic organisms. Although survival of H. azteca was not consistently affected from the first to the second sediment toxicity tests, dry weight was consistently reduced and related to Cu concentrations in soil, overlying water, and pore water. Furthermore, whole-body tissue Cu concentrations were significantly higher in H. azteca in all 10 soil-water treatments in the first sediment toxicity test and in all 4 soil-water treatments in the second sediment toxicity test compared to controls. Whole-body tissue concentrations and effects on dry weight were related to Cu exposures in soil, overlying water, and pore water. In these managed soil-water systems, small fish consuming H. azteca with high concentrations of Cu may be at risk.

Contamination Profiles of Antifouling Biocides in Selected Coastal Regions of Malaysia by Hiroya Harino; Takaomi Arai; Madoka Ohji; Ahmad Bin Ismail; Nobuyuki Miyazaki (pp. 468-478).

The concentrations of butyltins (BTs) in sediment from Peninsular Malaysia along the Strait of Malacca and their spatial distribution are discussed. The concentrations of BTs were high in the southern part of Peninsular Malaysia where there is a lot of ship traffic, because trade is prosperous. The concentrations of monobutyltin (MBT), dibutyltin (DBT), and tributyltin (TBT) in sediment from the coastal waters of Peninsular Malaysia were in the range 4.1–242 μg/kg dry weight (dw), 1.1–186 μg/kg dw, and 0.7–228 μg/kg dw, respectively. A higher percentage of TBT was observed in the area where TBT concentrations were high. The concentrations of monophenyltin (MPT), diphenyltin (DPT), and triphenyltin (TPT) were in the range <0.1–121 μg/kg dw, 0.4–27 μg/kg dw, and 0.1–34 μg/kg dw in sediment from Peninsular Malaysia, respectively. MPT was the dominant phenyltin species. MBT, DBT, and TBT in green mussel (Perna viridis) samples were detected in the range 41–102 μg/kg, 3–5 μg/kg, and 8–32 μg/kg, respectively. A tolerable average residue level (TARL) was estimated at 20.4 μg/kg from a tolerable daily intake (TDI) of 0.25 μg TBTO/kg body weight/day. The maximum value of TBT detected in green mussel samples was the value near the TARL. TPTs were not detected in green mussel samples. The concentrations of Diuron and Irgarol 1051 in sediment from Peninsular Malaysia were in the range <0.1–5 μg/kg dw and <0.1–14 μg/kg dw, respectively. High concentrations of these compounds were observed in locations where the concentrations of TBT were high. Sea Nine 211, Dichlofluanid, and Pyrithiones were not detected in sediment. The concentrations of antifouling biocides in Melaka and the Strait of Johor were investigated in detail. BTs were found in similar concentrations among all sampling sites from Melaka, indicating that BT contamination spread off the coast. However, Sea Nine 211, Diuron, and Irgarol 1051 in the sediment from Melaka were high at the mouth of the river. BT concentrations at the Strait of Johor were higher than those in Peninsular Malaysia and Melaka and were high at the narrowest locations with poor flushing of water. The concentrations of antifouling biocides were compared among Malaysia, Thailand, and Vietnam. A higher concentration and wide variations of TBT and TPT in sediment from Malaysia were observed among these countries. The Irgarol 1051 concentrations in sediment from Malaysia were higher than those in Thailand and Vietnam.

First Evidence of Altered Immune Responses and Resistance to Air Exposure in the Clam Chamelea gallina Exposed to Benzo(a)pyrene by Valerio Matozzo; Marta Monari; Jurgen Foschi; Otello Cattani; Gian Paolo Serrazanetti; Maria Gabriella Marin (pp. 479-488).

Effects of benzo(a)pyrene [B(a)P] (at a nominal concentration of 0.5 mg/L) on immune responses of the clam Chamelea gallina were investigated after 1, 7, and 12 days exposure. Total hemocyte count (THC), hemocyte volume, phagocytic activity, lysozyme-like activity in both hemocyte lysate (HL) and cell-free hemolymph (CFH) were measured. As unexpected alterations in hemocyte adhesion capability were observed in short-term hemocyte cultures for phagocytosis assays after a 1-day exposure, an adhesion test (not included in the original experimental setup) was performed after 7 and 12 days of exposure only. The survival-in-air test was carried out to evaluate general stress conditions in B(a)P-exposed clams. No alterations in THC was observed, whereas exposure for 7 and 12 days to B(a)P significantly decreased phagocytic activity and adhesion capability when compared with controls. Significant decreases in lysozyme activity were observed in CFH and HL, with respect to controls. B(a)P was also shown to alter the resistance to air exposure of clams. The LT₅₀ values fell from 9 days in control clams to 7 days in 1-day-exposed animals, and from 6 days in control clams to 5 days in 7-day-exposed bivalves. No significant variations in LT₅₀ values were recorded after 12 days of exposure. Results highlight a relationship between B(a)P exposure and alterations in hemocyte functionality and suggest that the contaminant induced irreversible immunosuppression in C. gallina, by altering phagocytic activity, adhesion capability, and enzymatic activity. Conversely, reduction in resistance to air exposure was reversible, suggesting that impairment of important physiological functions of clams occurred in the first phases of exposure only.

Relating Disparity in Competitive Foraging Behavior Between Two Populations of Fiddler Crabs to the Subcellular Partitioning of Metals by Jacques N. Khoury; Evelyn Powers; Pradyot Patnaik; William G. Wallace (pp. 489-499).

Behavioral changes in aquatic organisms such as reduced prey capture and decreased mobility have been linked to exposure to contaminants in the field. The purpose of this study was to compare competitive foraging and dominance behaviors of two populations of the fiddler crab, Uca pugnax, and to examine the relationship between tissue metal residues and observed differences in behavior. Foraging behavior (number of total scoops and scoops on a protein-rich patch) and dominance behavior (percentage of successful attacks) of fiddler crabs from an impacted site (Meredith Creek, New York) and a reference site (Tuckerton, New Jersey) were compared in the laboratory. Tuckerton (Tk) crabs were found to have twice the number of total scoops (70 vs. 38 scoops, p < 0.05) and three times the number of scoops on patch (34 vs. 10 scoops, p < 0.05) than Meredith (Me) crabs. No difference was observed between crab populations in the number of successful attacks (i.e., fights over the protein-rich patch). Analyses of total metal body burdens and metals associated with various subcellular fractions showed that, when compared with Tk crabs, Me crabs had higher levels of Ag, Cd, Cu, Ni, and Se in the heat-denatured proteins (HdeP) (i.e., enzymes). Metal bioaccumulation can have inhibitory effects on enzymes, which play an essential role in the regulation of various biochemical, metabolic, and physiological activities in crustaceans. This study suggests that there is a relationship between the accumulation of metals in HdeP (i.e., enzymes) and impairment of competitive foraging behavior in fiddler crabs. Additionally, this study shows that when compared with dominance behavior, foraging behavior is a more sensitive indicator of metal exposure and might be used as an end point in ecotoxicology studies.

Development of a Methodology for Successful Multigeneration Life-Cycle Testing of the Estuarine Sheepshead Minnow, Cyprinodon variegatus by G. M. Cripe; B. L. Hemmer; L. R. Goodman; J. C. Vennari (pp. 500-508).

Evaluation of effects on fish reproduction and development during chemical exposures lasting for multiple generations is sometimes limited by variable reproductive responses and the time required for the exposure. Established testing methods and the short life cycle of the sheepshead minnow, Cyprinodon variegatus, make this species particularly suitable for use in identifying potential impacts of contaminants in estuarine and marine environments. This study describes the refinement of life-cycle exposure methods that increased the reliability of reproduction in sheepshead minnows and reduced the time to maturation for larvae and juvenile fishes. A test of three spawning chamber designs, three sex ratios, and two photoperiods identified conditions that reduced the coefficient of variation in egg production from >100% to as little as 32%. The most reliable results were produced with groups of three female and two male fishes (all of similar size) when they were placed in a rectangular chamber and acclimated for 12 days. A test water temperature of 26.5 ± 2°C and a 14L:10D photoperiod resulted in fish producing a mean of 74 embryos per female per day, with a coefficient of variation of 31.8%. Egg fertility exceeded 90%, with a hatch rate of 95% for normal embryos (≥80% yolk) and a hatch rate of ≤45% for embryos containing ≤77% yolk. The length of time to grow larvae to spawning adult fish was reduced to ~60 days posthatch by feeding them flake food twice daily to satiation for 15 min, and it was observed that size (≥2.7 cm standard length) was critical for spawning readiness. Adult fish were prepared for the spawning assessment by adding frozen brine shrimp to their diet. Results of these experiments provide methods that are of particular interest in assessment of endocrine-disrupting chemicals that are known to affect reproduction.

Concentrations of Cadmium, Cobalt, Lead, Nickel, and Zinc in Blood and Fillets of Northern Hog Sucker (Hypentelium nigricans) from Streams Contaminated by Lead–Zinc Mining: Implications for Monitoring by C. J. Schmitt; W. G. Brumbaugh; T. W. May (pp. 509-524).

Lead (Pb) and other metals can accumulate in northern hog sucker (Hypentelium nigricans) and other suckers (Catostomidae), which are harvested in large numbers from Ozark streams by recreational fishers. Suckers are also important in the diets of piscivorous wildlife and fishes. Suckers from streams contaminated by historic Pb–zinc (Zn) mining in southeastern Missouri are presently identified in a consumption advisory because of Pb concentrations. We evaluated blood sampling as a potentially nonlethal alternative to fillet sampling for Pb and other metals in northern hog sucker. Scaled, skin-on, bone-in “fillet” and blood samples were obtained from northern hog suckers (n = 75) collected at nine sites representing a wide range of conditions relative to Pb–Zn mining in southeastern Missouri. All samples were analyzed for cadmium (Cd), cobalt (Co), Pb, nickel (Ni), and Zn. Fillets were also analyzed for calcium as an indicator of the amount of bone, skin, and mucus included in the samples. Pb, Cd, Co, and Ni concentrations were typically higher in blood than in fillets, but Zn concentrations were similar in both sample types. Concentrations of all metals except Zn were typically higher at sites located downstream from active and historic Pb–Zn mines and related facilities than at nonmining sites. Blood concentrations of Pb, Cd, and Co were highly correlated with corresponding fillet concentrations; log–log linear regressions between concentrations in the two sample types explained 94% of the variation for Pb, 73–83% of the variation for Co, and 61% of the variation for Cd. In contrast, relations for Ni and Zn explained <12% of the total variation. Fillet Pb and calcium concentrations were correlated (r = 0.83), but only in the 12 fish from the most contaminated site; concentrations were not significantly correlated across all sites. Conversely, fillet Cd and calcium were correlated across the range of sites (r = 0.78), and the inclusion of calcium in the fillet-to-blood relation explained an additional 12% of the total variation in fillet Cd. Collectively, the results indicate that blood sampling could provide reasonably accurate and precise estimates of fillet Pb, Co, and Cd concentrations that would be suitable for identifying contaminated sites and for monitoring, but some fillet sampling might be necessary at contaminated sites for establishing consumption advisories.

Endosulfan Application to a Stream Mesocosm: Studies on Fate, Uptake into Passive Samplers and Caged Toxicity Test with the Fish M. ambigua by Fleur Pablo; Ross V. Hyne (pp. 525-535).

A model mesocosm system was used to simulate the effect of endosulfan entering a waterway from episodic events such as accidental overspray or in runoff water containing contaminated sediment following storm events. The fate of technical endosulfan applied to a 24-stream mesocosm was compared in experiments where the pesticide was applied either directly as water contamination or after being pre-bound to sediment. The flow of water through the streams was discontinued for a 10–12 h period following the pesticide application. Following the water application, only approximately 3% of endosulfan remained in the streams after 4 days and then was not detectable after 7 days. In contrast, after application pre-bound to sediment, approximately 33% of the endosulfan remained in the streams after 4 days and 14% after 7 days. Additionally, with the sediment-bound application, the proportion of endosulfan was higher in the substrate (11%) after 7 days than in the overlying water (3%), and approximately 1% was oxidised to the sulphate form. The dissipation of endosulfan in the water column of both experiments followed a two-parameter exponential decay model characterised by a relatively fast first-order single-phase process. In sediment of both experiments and the gravel of the sediment-dosing experiment, the dissipation of endosulfan followed more closely a four-parameter bi-exponential decay model characterised by first-order kinetics of two fractions: the first fraction dissipates quickly, and in the longer term the second fraction dominates the overall dissipation with a slower rate. In the gravel section of the water-dosing experiment, endosulfan dissipation was characterised by relatively very slow two-parameter exponential decay. The overall dissipation rates of the α- and β-endosulfan isomers were significantly higher in the water-dosing than in the sediment-dosing experiment, except in the gravel section of the mesocosm. The uptake of the endosulfan into passive samplers constructed from polyethylene membrane bags containing trimethylpentane solvent (TRIMPS) placed in the overlying water was linear. In contrast, TRIMPS buried in sediment failed to uptake endosulfan from the sediment substrate, indicating that short-term deployment of passive samplers can only be used to determine time-weighted average concentrations of bioavailable chemicals in the water column. A 34-h LC50 of 2.8 μg/l [95% confidence interval (CI) 1.5–4.2 μg/l] for juveniles of the native fish Macquaria ambigua was obtained when exposed during the water-dosing experiment. This study demonstrated that the pulse entry of sediment contaminated with endosulfan into a receiving waterway was more persistent compared with direct aqueous contamination and the endosulfan would be bioavailable to pelagic organisms following a gradual partitioning to the water column.

Diseases of the Chilean Flounder Paralichthys adspersus (Steindachner, 1867) as Biomarkers of Marine Coastal Pollution Near the Itata River (Chile). Part I: In Situ Macroscopic Lesions by Maritza Leonardi; Jeanett Vera; Eduardo Tarifeño (pp. 536-545).

This study evaluated the health of the Chilean flounder Paralichthys adspersus inhabiting the marine coastal area influenced by the Itata River. Flounder were also sampled at two reference sites during the course of 1 year. The pathological examination was done following the ICES protocol: external and internal lesions, condition factor, hepatosomatic and spleen indexes, and number of erythrocytes, lymphocytes, and thrombocytes. The prevalence of fish with lesions differed significantly among sites. The flounder sampled in the Itata area were the most affected. The evaluation of the macroscopic lesions observed on the flounder caught in the Itata area revealed (1) seven different types of macroscopic lesions, (2) a high prevalence of epidermal irritation lesions, and (3) a normal K factor, hepatosomatic index, and blood cell count. Significant differences were found in epidermal irritation lesions between stages and sites and between sexes and sites. Juveniles and adults as well as males and females were affected. A seasonal analysis of the macroscopic lesions on the flounder caught in the Itata area showed significant differences for only the epidermal irritation lesions between the sampled seasons of the year; the flounder caught in winter 2006 had the highest prevalence (77%) of such lesions. These results are discussed in relation to the hydrographic conditions, the contents of inorganic, nutrient and other organic compounds in the water column, and the contents of organic compounds and metals in the sediments of the subtidal environment in the Itata area.

Diseases of the Chilean Flounder, Paralichthys adspersus (Steindachner, 1867), as a Biomarker of Marine Coastal Pollution Near the Itata River (Chile): Part II. Histopathological Lesions by Maritza Leonardi; Eduardo Tarifeño; Jeanett Vera (pp. 546-556).

This study evaluated the histopathological lesions of the Chilean flounder, Paralichthys adspersus, inhabiting the marine coastal area influenced by the Itata River (central Chile) in order to provide an environmental baseline given the plans to discharge effluents from a cellulose plant through a submarine pipe in the area. Flounder were also sampled at two reference sites over the course of 1 year. Pathological examinations and descriptions of histopathological lesions follow the ICES suggested protocol: internal and histopathological lesions, condition factor, and hepatosomatic and spleen indexes. The prevalence of fish with histopathological lesions differed significantly among sites. The flounder sampled in the Itata area were the most affected. Evaluation of histopathological lesions observed on the flounder caught in the Itata area revealed (i) 16 different types of histopathological lesions, (ii) a high prevalence of lesions in gills and epidermal and hepatic tissue, and (iii) a normal K factor and hepatosomatic index. Significant differences were found in epidermal hyperplasia (EH), chronic dermatitis, telangiectasis (TEL), localized edema in the base of lamellae (LE), fusion of secondary lamellae (FSL), foci of cellular alteration (FCA), melanomacrophagic centers (MMCs), and hemosiderin (HEM) lesions among sites and among sites by season of the year. Winter 2006 was the most affected. A seasonal analysis of histopathological lesions on flounder caught in the Itata area showed significant differences for EH, progressive focal invasion of muscle fibers (PFIMF), TEL, LE, FSL, lamellar bifurcation, hepatitis, FCA, MMCs, and HEM lesions between the sampled seasons of the year; flounder caught in winter 2006 had the highest prevalence of these lesions except for PFIMF, which was higher in winter 2007. These results are discussed in relation to the contents of inorganic and organic compounds in the water column and the contents of organic compounds in sediments of the subtidal environment in the Itata area.

Effects of Copper Sulfate on Growth, Development, and Escape Behavior in Epidalea calamita Embryos and Larvae by E. García-Muñoz; F. Guerrero; G. Parra (pp. 557-565).

Epidalea calamita embryos at Gosner stages 3 and 19, and larvae at Gosner stage 25, were exposed to different copper sulfate concentrations, ranging from 0.05 to 0.40 mg Cu L⁻¹, in 96-h acute toxicity tests. Embryonic and larval mortality, development, growth, and larval escape behavior were evaluated. LC₅₀ at 96 h obtained at Gosner stages 3, 19, and 25 were 0.22, 0.08, and 0.11 mg Cu L⁻¹, respectively. Embryonic and larval developments were delayed after 96 h of copper sulfate exposure. Growth was also affected and individuals in control treatments grew to twice the size of those exposed to copper concentrations over 0.2 mg Cu L⁻¹ during the experiments initiated at Gosner stage 19. Escape behavior was altered after 96 h of copper sulfate exposure; larvae showed shorter distances moved and abnormal displacement types. However, after 4 days of recovery process, most of the larvae showed normal escape behavior. For amphibians that develop in temporary wetlands, increased development time, lower size, and altered escape behavior might have repercussions on the number of individuals that can successfully complete metamorphosis and, consequently, on recruitment.

Effects of Single and Combined Embryonic Exposures to Herbicide and Conspecific Chemical Alarm Cues on Hatching and Larval Traits in the Common Frog (Rana temporaria) by Anne-Lise Mandrillon; Philippe Saglio (pp. 566-576).

Recent studies indicate that amphibian embryos can exhibit hatching plasticity in response to chemical cues indicative of a predation risk. However, data are lacking concerning the possible impacts of waterborne contaminants on such a process. To investigate this impact, we raised eggs of the common frog (Rana temporaria) until hatching in water contaminated with sublethal concentrations (0.01, 0.1, and 1 mg/L) of amitrole, a widely used triazole herbicide, either with or without the presence of chemical alarm cues from crushed conspecific tadpoles. Embryonic exposure to conspecific alarm cues resulted in a delay in hatching, reduced growth, and decreased larval activity, regardless of the amitrole concentration present during the incubation. Conspecific cues also induced morphological changes, but only in individuals incubated in water contaminated with the highest amitrole concentration. The herbicide impacts on hatching time were restricted to embryos incubated in the presence of conspecific cues, with individuals exposed to 0.1 and 1 mg/L showing an extended embryonic period compared to controls in uncontaminated water. Whether tested alone or in combination with conspecific cues, amitrole also induced slight morphological changes but did not affect larval growth or behavioral activity. Thus, depending on the trait considered, both chemical stressors exhibited either single or interactive effects. Furthermore, our data indicate that a stressing factor without apparent impact when tested alone could exert effects when combined with another stressor. Such results highlight the importance of considering multiple environmental factors and biological traits when examining stress-induced phenotypic variability.

Metals and Trace Elements in Giant Garter Snakes (Thamnophis gigas) from the Sacramento Valley, California, USA by Glenn D. Wylie; Roger L. Hothem; Darrin R. Bergen; Lisa L. Martin; Robert J. Taylor; Brianne E. Brussee (pp. 577-587).

The giant garter snake (GGS; Thamnophis gigas) is a federally listed threatened species endemic to wetlands of the Central Valley of California. Habitat destruction has been the main factor in the decline of GGS populations, but the effects of contaminants on this species are unknown. To contribute to the recovery of these snakes, the U.S. Geological Survey (USGS) began studies of the life history and habitat use of GGSs in 1995. During a series of investigations conducted from 1995 to the present, specimens of dead GGSs were opportunistically collected from the Colusa National Wildlife Refuge (CNWR), the Natomas Basin, and other sites in northern California. Whole snakes were stored frozen for potential future analysis. As funding became available, we analyzed tissues of 23 GGSs to determine the concentrations of total mercury (Hg) and other trace elements in livers and concentrations of Hg in brains and tail clips. Mercury concentrations (μg/g, wet weight) ranged from 0.08 to 1.64 in livers, 0.01 to 0.18 in brains, and 0.02 to 0.32 in tail clips. In livers, geometric mean concentrations (μg/g, dry weight) of arsenic (25.7) and chromium (1.02) were higher than most values from studies of other snakes. Mercury concentrations in tail clips were positively correlated with concentrations in livers and brains, with the most significant correlations occurring at the Natomas Basin and when Natomas and CNWR were combined. Results indicate the value of using tail clips as a nonlethal bioindicator of contaminant concentrations.

Toxic Element Concentrations in the Razorbill Alca torda (Charadriiformes, Alcidae) in Portugal by A. R. Ribeiro; C. Eira; J. Torres; P. Mendes; J. Miquel; A. M. V. M. Soares; J. Vingada (pp. 588-595).

The present study provides the first data on inorganic element levels (As, Cd, Co, Cr, Cu, Hg, Mn, Pb, Se, and Zn) in juvenile, immature, and adult razorbills (Alca torda) collected along the central coast of Portugal. Element concentrations were assessed by ICP-MS in kidney, liver, muscle, and feathers of 28 razorbills, including 4 juveniles, 17 subadults, and 7 adults. The effect of age and tissue on element accumulation was also assessed. The detected levels in razorbills may indicate a possible contamination risk by Hg and Cr. With respect to bird tissues, higher accumulation of Se and Cd was detected in kidney, Zn and Pb in feathers, and As and Mn in liver. Age was found to affect the accumulation of Cd, Cr, Cu, Hg, and Mn, juveniles presenting higher levels of Cu and Mn than older individuals. In razorbill kidney, Zn–Hg constituted the most significant relationship among metal concentrations. Liver presented the highest number of significant relationships (mostly involving Zn and Co). With regard to feathers, the most significant relationships involved Se, Zn, Cr and Cu concentrations. Positive linear relationships were detected among kidney, liver, and muscle, with emphasis on relationships involving Se and Hg, which may be indicative of similar accumulation/regulation mechanisms in those organs. Element concentrations are discussed in view of possible detoxification mechanisms in seabirds.

Mercury and Other Metals in Feathers of Common Eider (Somateria mollissima) and Tufted Puffin (Fratercula cirrhata) from the Aleutian Chain of Alaska by Joanna Burger; Michael Gochfeld (pp. 596-606).

We analyzed arsenic, cadmium, chromium, lead, manganese, mercury, and selenium in the feathers of common eiders (Somateria mollissima) and tufted puffins (Fratercula cirrhata) from Amchitka and Kiska islands (Aleutians). Between species, puffins had 10 times higher chromium (arithmetic mean = 1820 ppb), 7.5 times higher selenium (mean = 6600 ppb), and 3 times higher mercury (mean = 2540 ppb) than eiders. Eiders had significantly higher levels of manganese than puffins. Puffins are higher on the food chain than eiders, which is reflected in their generally higher levels of metals in their feathers. Interisland differences were generally small, and there were few significant differences as a function of the three nuclear test locations on Amchitka. The only sex-related difference was that female puffins had higher mercury than males (arithmetic mean of 3060 ppb vs. 2270 ppb). Mean levels of metals in the feathers of puffins and eiders from the Aleutians were low compared with comparable studies elsewhere, and the relatively low levels of metals do not indicate the potential for adverse behavioral or reproductive effects in the birds themselves, nor pose concern for other consumers, including subsistence hunters.

Temporal Trends (1992–2007) of Perfluorinated Chemicals in Northern Sea Otters (Enhydra lutris kenyoni) from South-Central Alaska by Kimberly Hart; Verena A. Gill; Kurunthachalam Kannan (pp. 607-614).

Perfluorinated chemicals (PFCs) have been detected in abiotic and biotic matrices worldwide, including the Arctic Ocean. Considering these chemicals’ persistent and bioaccumulative potentials, it was expected that levels of PFCs, like those of many legacy organic pollutants, would respond slowly to the restrictions in production and usage. Temporal trend studies in remote areas, such as the Arctic, can help determine the chronology of contamination and the response of the environment to regulations on PFCs. Prior to this study, temporal trends of PFCs in Alaskan coastal waters had not been examined. In the present study, concentrations of six PFCs were determined in livers of northern sea otters (Enhydra lutris kenyoni) collected from three areas in south-central Alaska (Prince William Sound, n = 36; Resurrection Bay, n = 7; Kachemak Bay, n = 34) from 1992 to 2007. Additionally, previously published profiles and concentrations of PFCs in southern sea otters from California and Asian sea otters from Kamchatka (Russia) were compared to our new data, to determine the geographical differences in PFC profiles among these three regions in the Pacific Ocean. Perfluorooctanesulfonate (PFOS), perfluorooctanesulfonamide (PFOSA), and perfluorononanoate (PFNA) were the predominant PFCs found in the livers of northern sea otters from 1992 to 2007. Other PFCs, such as perfluorooctanoate (PFOA), perfluoroundecanoate (PFUnDA), and perfluorodecanoate (PFDA), were detected less frequently, and at low concentrations. Overall, from 2001 to 2007, a decrease in concentrations of PFOS was found in northern sea otters, suggesting an immediate response to the phase-out in 2000 of perfluorooctanesulfonyl-based compounds by a major producer in the United States. In contrast, concentrations of PFNA in northern sea otters increased by 10-fold from 2004 to 2007. These results indicate that the contribution by PFNA to ΣPFC concentrations is increasing in northern sea otters. The profiles (i.e., composition of individual PFC to ΣPFC concentration) of PFCs in northern sea otters from Alaska were similar to those reported for southern sea otters from California, but were considerably different from the profiles reported for Asian sea otters from Russia, suggesting differences in point sources of exposure.

Prenatal and Early Childhood Exposure to Mercury and Methylmercury in Spain, a High-Fish-Consumer Country by Sergi Díez; Sandra Delgado; Inmaculada Aguilera; Jenaro Astray; Beatriz Pérez-Gómez; Maties Torrent; Jordi Sunyer; Josep M. Bayona (pp. 615-622).

Exposure to mercury, a risk factor for neurodevelopmental toxicity, was assessed in Spanish children (preschool children and newborns, n = 218) in a four-locations survey by performing mercury determination in hair. To assess the prenatal and children’s exposure and its potential risk, total mercury (THg) and methylmercury (MeHg) were analyzed and examined for associations with maternal sociodemographic characteristics and dietary intake through interviews and food frequency questionnaires. The mean THg in hair was 0.94 μg/g, ranging from 0.19 to 5.63 μg/g in preschool children and 1.68 μg/g (0.13–8.43 μg/g) in newborns. Associations between mercury levels in hair and fish consumption frequency were found regardless of the group evaluated. Neither other food item nor maternal covariates were associated with mercury levels in the newborn group. In children, the mean THg values among frequent fish consumers (more than four times per week) were almost threefold higher compared with non-consumers (1.40 vs. 0.49 μg/g). Newborns from mothers who had intake of fish two or more times per week exhibited nearly threefold higher hair levels than those who rarely or never consumed fish (2.26 vs. 0.78 μg/g). Finally, mercury levels in hair exceeded the EPA reference dose (RfD) of 0.1 μg Hg/kg body weight per day (equivalent to 1 μg Hg/g hair) in 42% of the population studied. Overall, we conclude that levels of mercury in Spain are among the highest in the non-exposed populations probably because of the relatively high fish consumption.

Occupational Exposure to Pesticides: Blood Cholinesterase Activity in a Farming Community in Ghana by William J. Ntow; Laud M. Tagoe; Pay Drechsel; Peter Kelderman; Elvis Nyarko; Huub J. Gijzen (pp. 623-630).

A survey was undertaken to establish the extent of pesticide exposure in a farming community. Cholinesterase (ChE) activity in whole blood was used as a marker for assessing exposure to pesticides. Complete data were gathered for 63 farmers at Akumadan (exposed) and 58 control subjects at Tono, both prominent vegetable-farming communities in Ghana, by means of a questionnaire and blood cholinesterase analyses (acetylcholine assay). Although whole-blood ChE was significantly lower in the exposed than the control participants, it was not significantly correlated with either confounders of age, sex, body weight, and height or high-risks practices. The high-risks practices revealed during the survey included lack of use of personal protective clothing, short reentry intervals, and wrong direction of spraying of pesticides by hand or knapsack sprayer. About 97% of exposed participants had experienced symptoms attributable to pesticide exposure. The frequent symptoms were reported as weakness and headache. There is the need to review safety precautions in the use and application of pesticides in Ghana.

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Archives of Environmental Contamination and Toxicology (v.56, #3)