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Archives of Environmental Contamination and Toxicology (v.54, #3)
Inclusion Effect of Alpha-Cyclodextrin on Chemical Degradation of Malathionin Water by Anping Zhang; Weiping Liu (pp. 355-362).
Chemical degradation of malathion in water is one of the important environmental processes of malathion, and plays a critical role in detoxification of malathion. Alpha-cyclodextrin (α-CD), one of the cyclic oligosaccharides different from beta-cyclodextrin (β-CD) in glucose units, solubility, and size of cavity, is capable of producing an environmental effect different from those of the latter CD and its derivatives. This work evaluated the effect of α-CD on chemical degradation of malathion in water in an attempt to further study the effects of different CDs on hydrolysis of malathion and assess the potential applications of α-CD in remediation of malathion contamination. The results showed that α-CD had a remarkable facilitative effect on the hydrolysis of malathion in both buffer solutions and natural surface waters. The facilitative effects of α-CD were an obverse function of pH value and inverse function of temperature. The rate constant of malathion hydrolysis increased with increasing the concentration of α-CD in both types of waters. Urea, a compound widely used in agriculture, decreased the facilitative effect of α-CD at 25°C and pH 9.0. The formation of inclusion complexes between α-CD and malathion was evidenced by nuclear magnetic resonance studies.
Keywords: Cyclodextrin; Inclusion complex; Malathion; Hydrolysis; Urea
Outdoor Air PCB Concentrations in Three Communities Along the Upper Hudson River, New York by Patrick M. Palmer; Erin E. Belanger; Lloyd R. Wilson; Syni-An A. Hwang; Rajinder S. Narang; Marta I. Gomez; Michael R. Cayo; Lorie A. Durocher; Edward F. Fitzgerald (pp. 363-371).
Outdoor air polychlorinated biphenyl (PCB) concentrations were measured in upstate New York as part of a nonoccupational exposure investigation. The adjacent study communities of Hudson Falls and Fort Edward contain numerous sites of current and former PCB contamination, including two capacitor-manufacturing facilities. Outdoor air PCB concentrations in the study municipalities were significantly higher than in the comparison municipality of Glens Falls. Total PCB concentrations in the study area ranged from 0.102 to 4.011 ng/m3 (median: 0.711 ng/m3). For the comparison area, concentrations ranged from 0.080 to 2.366 ng/m3 (median: 0.431 ng/m3). Although our sampling was not designed to identify point sources, the presence of PCB-contaminated sites in the study area likely contributed to this observed difference in concentration. While elevated relative to the comparison area, total PCB concentrations in the study area are lower than those in other communities with known PCB-contaminated sites, and similar to levels reported in other locations from the northeastern United States.
Sediment Concentrations of Trace Metals in the Berre Lagoon (France): An Assessment of Contamination by Alessandra Accornero; Rossella Gnerre; Loredana Manfra (pp. 372-385).
This paper reports the concentrations of eight trace metals (Cr, Zn, Cu, Pb, Ni, As, Cd, and Hg) in the surficial sediments of the Berre lagoon. This is a typical Mediterranean lagoon, seriously affected by human activities since the 1930s, when it became one of the most important industrial sites in France. The overall range of concentrations is 38–428 mg kg−1 for chromium, 50–151 mg kg−1 for zinc, 11–48 mg kg−1 for copper, 18–82 mg kg−1 for lead, 18–56 mg kg−1 for nickel, 4–10 mg kg−1 for arsenic, 0.2–1.6 mg kg−1 for cadmium, and 0.15–0.40 mg kg−1 for mercury. The spatial distribution of concentrations largely mirrors the localization of major impact sources, with the most affected area restricted to a radius of a few kilometers from point sources, due to the environmental conditions of the outfall zone (fine sediments, low hydrodynamic regime, confinement), which favor the in situ accumulation of pollutants. The extent of contamination from trace metals in the lagoon sediments is evaluated through a three-pronged approach: (i) by comparison with other areas (see Table 3 for an up-to-date review of trace metal concentrations in lagoon systems and coastal regions of the world ocean); (ii) by evaluating the metal enrichment in the sediments through the calculation of concentration factors (CF) for each trace metal and by combining the CFs to estimate a Metal Pollution Index (MPI) taking into account the differences in toxicity of trace metals; and (iii) by defining a potential level of biological risk by the use of quality criteria such as the Threshold Effect Level (TEL) and Effects Range–Low (ER-L) benchmarks. On the basis of the calculated CFs, sediments appear as particularly enriched with Pb and Cd throughout the lagoon and with Cr and Zn at some sites. Although no site can be classified as “unpolluted” when looking at the calculated MPIs, two regions—the Vaïne pond and the southwestern area—have been identified as critical points of contamination. Trace metal inputs to the lagoon need to be kept under strict control in the future, with particular regard to Ni, Cr, Pb, and Cu that, on the basis of TEL and ER-L benchmarks, already appear associated with a potential biological risk.
Keywords: Coastal lagoon; Sediments; Trace metals; Metal Pollution Index; TEL and ER-L benchmarks; NW Mediterranean
Organochlorine Pesticides in the Sediment Core of Gwangyang Bay, South Korea by Yun-Seok Kim; Heesoo Eun; Hyeon-Seo Cho; Kyoung-Soo Kim; Toshihiro Sakamoto; Eiki Watanabe; Koji Baba; Takao Katase (pp. 386-394).
The nine organochlorine pesticides (OCPs) in the sediment samples taken from Gwangyang Bay, which is a heavy chemical industrial region in South Korea, are analyzed to evaluate their contaminations during the past 50 years. The vertical distributions of ΣOCPs concentration in the sediment core were in good agreement with the temporal amount of pesticides used in South Korea except for the top sediment layer. The DDTs were predominant, their concentrations ranging from 78.0 to 202 pg/g dry wt and attributed more than 60% to ΣOCPs in all the sediment layers. Based on the ratio of DDT metabolite compositions, the DDT contamination in the top layer might be caused from recent input. This is due to the highest residual concentration of OCPs in the top layer. Although HCB and mirex have been unregistered as pesticides in South Korea, two compounds were detectable in all of the sediment samples in the range from 0.243 to 16.7 pg/g dry wt in the study area. The emission source of HCB in the sediment core could be estimated to be due to incomplete combustion in the industrial chemical processes rather than pesticide application. Regarding horizontal distribution of ΣOCPs, the concentration was slightly higher than for the inner bay than the outer bay. The OCPs in the sediments of Gwangyang Bay were compared with those of other countries by hierarchical cluster analysis and principal component analysis.
Keywords: Persistent organic pollutants; Organochlorine pesticides; Sediment core; Characterization; Gwangyang Bay
Historical Distribution of PCDDs, PCDFs, and Coplanar PCBs in Sediment Core of Ariake Bay, Japan by Yun-Seok Kim; Heesoo Eun; Takao Katase (pp. 395-405).
Persistent organic pollutants, particularly polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), coplanar polychlorinated biphenyls (co-PCBs) and toxic equivalent quantity (pg TEQ g−1) were determined in sediment samples collected from Ariake Bay, Japan. The total concentration of PCDDs/DFs in surface sediment of the Yabe River (17,000 pg g−1 dry wt) was approximately 2.5-fold higher than that of the Chikugo River (7,000 pg g−1 dry wt) which has the highest flow amount of about 40% inputting to the northern Bay. The congener profile suggested that dioxin sources could be close to the study area. The PCDDs concentration (12,000 pg g−1 dry wt) in the sediment layer, which was corresponding to the 1960s, was reflected on the pentachlorophenol (PCP) contamination occurring at that time in Ariake Bay. The reflecting of PCP in the sediment core was significantly considered by hierarchical cluster analysis. Based on isomer-specific analysis, the tetrachlorodibenzo-p-dioxin composition showed a gradual increase from 1978–1982 toward the surface, indicating that the pollution source at that period might be more influenced by chloronitrofen than PCP. This fact was supported, based on the ratio of ΣPCDD to ΣPCDF concentration. The PCDDs/DFs-derived TEQ contributed more than 90% of the ΣTEQ (PCDDs/DFs and co-PCBs) in all the detected sediment layers. The contribution of PCBs to the total TEQ was low; however, an increasing historical trend of concentration was clearly observed.
Keywords: PCDDs/DFs; Coplanar PCBs; Dioxin equivalents; Sediment core; Historical pollution; Ariake Bay
Reductive Dechlorination of Methoxychlor and DDT by Human Intestinal Bacterium Eubacterium limosum Under Anaerobic Conditions by You-Jin Yim; Jiyoung Seo; Su-Il Kang; Joong-Hoon Ahn; Hor-Gil Hur (pp. 406-411).
Methoxychlor [1,1,1-trichloro-2,2-bis(p-methoxyphenyl)ethane], a substitute for 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), is a compound of environmental concern because of potential long-term health risks related to its endocrine-disrupting and carcinogenic potency. In order to determine the metabolic fate of methoxychlor and DDT in the human intestinal gut, Eubacterium limosum (ATCC 8486), a strict anaerobe isolated from the human intestine that is capable of O-demethylation toward O-methylated isoflavones, was used as a model intestinal microbial organism. Under anaerobic incubation conditions, E. limosum completely transformed methoxychlor and DDT in 16 days. Based on gas chromatography–mass chromatography analyses, the metabolites produced from methoxychlor and DDT by E. limosum were confirmed to be 1,1-dichloro-2,2-bis(p-methoxyphenyl)ethane (methoxydichlor) and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD), respectively. This study suggests that E. limosum in the human intestinal gut might be a participant in the reductive dechlorination of methoxychlor to the more antiandrogenic active methoxydichlor.
Keywords: Methoxychlor; DDT; Eubacterium limosum ; Reductive dechlorination
Impact of Heavy Metals (Copper, Zinc, and Lead) on the Chlorophyll Content of Some Mosses by K. Shakya; M. K. Chettri; T. Sawidis (pp. 412-421).
The effects of the heavy metals copper (Cu), zinc (Zn), and lead (Pb) on the chlorophyll content of two mosses Thuidium delicatulum (L.) Mitt. and T. sparsifolium (Mitt.) Jaeg., as well as leafy liverwort Ptychanthus striatus (Lehm. & Linderb.) were examined to understand the impact of metal accumulation on the chlorophyll content of mosses and leafy liverwort, which are found only in uncontaminated sites of the Kathmandu valley. These plants were treated with different concentrations of CuCl2, ZnCl2, and Pb(NO3)2, ranging from 10−10 M to 10−2 M, in isolation and in combination under experimental conditions. Metal accumulation in the plant bodies increased with metal concentrations. Cu accumulation showed a significant inhibitory effect on chlorophyll-a, chlorophyll-b, and total chlorophyll in the mosses and the leafy liverwort. An insignificant decrease in chlorophyll content in both Thuidium species, but a significant decrease in leafy liverwort, was observed after Zn and Pb accumulation. Chlorophyll-a decreased significantly in T. sparsifolium; chlorophyll-b and total chlorophyll decreased significantly in T. delicatulum; and all chlorophyll contents decreased insignificantly in P. striatus after accumulation of Cu+Zn+Pb ions together from mixed metal solution. The ratio of chlorophyll-a to -b decreased more rapidly in both Thuidium species, with higher concentrations occurring when Cu+Zn+Pb ions were together than when Cu, Zn, or Pb ions were alone. This indicated a more destructive effect of Cu metals on the chlorophyll contents of both Thuidium species. High concentrations of Cu are known to activate oxidative damage and alter cell-membrane properties by lipid peroxidation, thereby demonstrating the inhibitory effect on the enzymes involved in chlorophyll production. The greater loss of chlorophyll from heavy-metal accumulation in P. striatus than in T. delicatulum and T. sparsifolium may have been caused by relatively more K+ efflux in leafy liverwort than in the mosses, thus indicating their differences in membrane integrity.
Distribution of Persistent Organohalogen Compounds in Pine Needles from Selected Locations in Kentucky and Georgia, USA by Bommanna G. Loganathan; Kurunthachalam Senthil Kumar; Kosta D. Seaford; Kenneth S. Sajwan; Nobuyasu Hanari; Nobuyoshi Yamashita (pp. 422-439).
Epicuticular wax of pine needles accumulates organic pollutants from the atmosphere, and the pine needle samples have been used for monitoring both local and regional distributions of semivolatile organic air pollutants. One-year-old pine needles collected from residential and industrial locations in western Kentucky and the vicinity of Linden Chemicals and Plastics, a Superfund Site at Brunswick, Georgia, were analyzed for polychlorinated biphenyls (PCBs), major chlorinated pesticides, and polychlorinated naphthalenes (PCNs). Total PCB concentrations in pine needles from Kentucky ranged from 5.2 to 12 ng/g dry weight (dw). These sites were comparatively less polluted than those from the Superfund Site, which had total PCB concentrations in pine needles in the range of 15–34 ng/g dw. Total chlorinated pesticides concentrations in pine needles ranged from 3.5 to 10 ng/g dw from Kentucky. A similar range of concentrations of chlorinated pesticides (7.3–12 ng/g dw) was also found in pine needle samples from the Superfund site. Total PCN concentrations in pine needles ranged from 76 to 150 pg/g dw in Kentucky. At the Superfund Site, total PCN concentrations ranged from 610 pg/g dw to 38,000 pg/g dw. When the toxic equivalencies (TEQs) of PCBs in pine needles were compared, Kentucky was relatively lower (0.03–0.11 pg/g dry wt) than the TEQs at the Superfund Site (0.24–0.48 pg/g dry wt). The TEQs of PCNs from Kentucky (0.004–0.067 pg/g dw) were much lower than the TEQs from locations near the Superfund Site (0.30–19 pg/g dry wt). The results revealed that pine needles are excellent, passive, nondestructive bioindicators for monitoring and evaluating PCBs, chlorinated pesticides, and PCNs.
Growth of Corophium volutator Under Laboratory Conditions by Belinda J. Kater; Johan G. Jol; Mathijs G. D. Smit (pp. 440-446).
Temperature-dependent growth is an important factor in the population model of Corophium volutator that was developed to translate responses in a 10-day acute bioassay to ecological consequences for the population. The growth rate, however, was estimated from old data, based on a Swedish population. Therefore, new growth rates are estimated herein from two experiments using Corophium volutator. To save time, a tool was developed to use image analysis to measure Corophium volutator. The experiments show that Corophium volutator has a low growth rate at low temperatures (5–10°C). At higher temperatures no difference in growth rate between 15°C and 25°C was found. The growth rate from these experiments is comparable to data found in literature. A new relationship between temperature and individual growth was estimated, and incorporated into the Corophium population model. As the model also uses the same temperature relationship for reproduction, the modelled population growth rate at different temperatures changes as a result of the new data. The new growth rate and the updated temperature relationship result in reduced tolerance to external stressors, as previously predicted by the model.
Phenotypic and Behavioral Defects Caused by Barium Exposure in Nematode Caenorhabditis elegans by D.-Y. Wang; Y. Wang (pp. 447-453).
To examine the possible phenotypic defects from barium exposure, a model organism, Caenorhabditis elegans, was chosen to analyze the multiple toxicities in barium-exposed animals. Endpoints of life span, body size, brood size, generation time, head thrash, and body bend were selected for the assessment of barium toxicity. High concentrations (75 μM and 200 μM) of barium exposure caused severe life-span defects. Body sizes of exposed animals were markedly reduced compared to the controls, and high concentrations of barium exposure (75 μM and 200 μM) caused the appearance of vulva abnormality. In addition, barium exposure resulted in severe defects in reproductive capacity and reproductive speed. Body bends and head thrashes were also severely impaired after barium exposure. Furthermore, the stress responses to barium exposure suggest severe barium toxicity. The observed severe locomotion behavior and life-span defects in nematodes might be largely due to the deposition of barium toxicity in the muscle and intestine systems, respectively. Our data suggest that barium exposure could cause multiple biological defects by affecting the life span, development, reproduction, and locomotion behaviors. These multiple biological defects provide a new evaluation system to monitor the toxicity from barium exposure.
Keywords: Barium exposure; Multiple biological defects; Caenorhabditis elegans
Acute Toxicity of Waterborne Cd, Cu, Pb, Ni, and Zn to First-Instar Chironomus riparius Larvae by K. M. Béchard; P. L. Gillis; C. M. Wood (pp. 454-459).
The acute toxicities of waterborne Cd, Cu, Pb, Ni, and Zn were determined in the first-instar larvae (generally considered to be the most sensitive) of Chironomus riparius, under standardized conditions. Toxicity tests were conducted in soft water (hardness, 8 mg/L as CaCO3 equivalents) in the absence of food and were limited to 24 h to avoid control mortality associated with food deprivation. For each metal, a logarithmic range of concentrations was tested between 0 and 25 mg/L. First-instar C. riparius are most sensitive to Pb, with a 24-h LC50 of 0.61 mg/L (CI of 0.26–1.15 mg/L), and to Cu, with a 24-h LC50 of 2.09 mg/L (CI of 1.57–2.96 mg/L). The LC50 for Cd was 9.38 mg/L, while the LC50s for Zn and Ni were both higher than the highest tested concentration of 25 mg metal/L. Our results found that even first-instar chironomid larvae are well protected by both the current CCME Canadian water quality guidelines for the protection of aquatic life and the USEPA Water Quality Criteria, as LC50s were at least 25 times higher than the guideline concentrations.
Keywords: Chironomids; Toxicity; LC50; Cd; Cu; Pb; Ni; Zn
Toxicity of Un-ionized Ammonia, Nitrite, and Nitrate to Juvenile Bay Scallops, Argopecten irradians irradians by James C. Widman Jr.; Shannon L. Meseck; George Sennefelder; David J. Veilleux (pp. 460-465).
Juvenile bay scallops (7.2–26.4 mm) were exposed for 72 h to different concentrations of un-ionized ammonia, nitrite, or nitrate. Using the Trimmed Spearman Karber method, 50% lethal concentrations (LC50) and 95% confidence limits were calculated individually for each. Un-ionized ammonia concentrations above 1.0 mg N-NH3/L resulted in 100% scallop mortality within 72 h. The 72-h LC50 for un-ionized ammonia was calculated at 0.43 mg N/L. At nitrite concentrations of 800 mg N/L or higher 100% mortality was observed. The 72-h LC50 for nitrite was calculated at 345 mg N/L. Nitrate was the least toxic, with 100% mortality observed at a concentration of 5000 mg N/L. The calculated nitrate 72-h LC50 was 4453 mg N/L. Our results indicate that un-ionized ammonia is the most lethal nitrogenous waste component to bay scallops.
Keywords: Bay scallops; Un-ionized ammonia; Toxicity; Nitrite; Nitrate
Acute Toxicity of Aqueous Copper, Cadmium, and Zinc to the Mayfly Rhithrogena hageni by Stephen F. Brinkman; Walter D. Johnston (pp. 466-472).
Heptageniid mayfly nymphs have been suggested as sensitive indicators of metal contamination in streams based on biomonitoring studies, experimentation in situ, and experimentation in microcosm. Laboratory tests were conducted to evaluate the sensitivity of Rhithrogena hageni, a heptageniid mayfly, to waterborne copper, cadmium, and zinc. Tests were conducted with soft water (hardness = 40–50 mg/L) at about 12°C. Toxicity endpoints were survival and moulting (%/day). Median 96 hr lethal concentrations were 0.137, 10.5, and 50.5 mg/L for copper, cadmium and zinc, respectively. The average daily moulting rate of survivors significantly decreased after exposure to these metals in solution.
Spatial and Temporal Trends of Mercury Concentrations in Young-of-the-Year Spottail Shiners (Notropis hudsonius) in the St. Lawrence River at Cornwall, ON by Emily S. Choy; Peter V. Hodson; Linda M. Campbell; Adrienne R. Fowlie; Jeff Ridal (pp. 473-481).
The St. Lawrence River at Cornwall, Ontario is an “Area of Concern” because of mercury (Hg) biomagnification from bottom sediments. To assess the spatial and temporal distribution of Hg in the food web, young-of-the-year (YOY) spottail shiners (Notropis hudsonius) were collected in August 2005 from five sites along the Cornwall waterfront within a Hg-contaminated zone and two reference zones. The results were compared to analyses made between 1979 and 2000 by the Ontario Ministry of the Environment. Total Hg concentrations in spottail shiners from the contaminated zone were significantly higher than in reference zones, confirming previous observations. Within the contaminated zone, there were significant differences in Hg concentrations among three sites spaced about 500 m apart, consistent with a high degree of site fidelity of YOY fish and suggesting a possible internal source of Hg. Hg concentrations in spottail shiners are decreasing regionally, although year-to-year variability was high, particularly in the contaminated zone. Stable isotope analyses of spottail shiners did not reveal any differences in nitrogen isotope composition among zones that would indicate differences in food-web structure and Hg biomagnification. However, carbon sources at an upstream reference zone were not the same as within the Area of Concern. Differences in carbon isotope composition at two sites within the contaminated zone corresponded to differences in Hg concentrations, consistent with a unique internal source of Hg. The variation in Hg contamination of YOY spottail shiners over fine spatial and temporal scales provide important insights about the potential release of Hg from contaminated sediments and the role of climate in regional trends. Sessile YOY fish provide a precise indicator for demonstrating these differences and for assessing their cause.
Keywords: Mercury; Young-of-the-year fish; Stable isotopes; Aquatic food web; Monitoring
Juvenile Tilapia (Oreochromis mossambicus) Strive to Maintain Physiological Functions After Waterborne Copper Exposure by Su Mei Wu; Hui Ru Ding; Li-Yih Lin; Yu-Siang Lin (pp. 482-492).
Juvenile tilapia were acutely exposed to 0.2 and 2 mg/L Cu2+ for up to 144 h. The Na+-K+-ATPase (NKA)-specific activity in the gills of tilapia exposed to 0.2 mg/L Cu2+ significantly decreased over 48–72 h and was restored to the control level after 96 h, but was again depressed during 120–144 h. The whole-body Cl− levels significantly decreased after 48 h, but recovered shortly afterwards and continued to do so until 144 h with 0.2 mg/L Cu exposure. During 48–72 h, the numbers of the wavy-convex type of mitochondria-rich (MR) cells appeared to significantly increase and the cortisol content also significantly increased. Changes in MR cell morphology might be necessary in order to enhance Cl− uptake, and this might be related to changes in cortisol levels. Whole-body Na+ concentrations had significantly decreased by 72 h, but recovered during 96–144 h. Whole-body Cu2+ concentrations also significantly increased compared to the initial concentration during 72–144 h of Cu exposure. All measured parameters (NKA activity, Na+ concentration, and MR cell numbers) significantly decreased in fish exposed to 2 mg/L Cu, and no recovery was observed. These data demonstrate that juvenile tilapia strived to maintain physiological functions after exposure to sub-lethal concentrations of Cu.
Keywords: Copper; Teleost; Sodium pump; Compensation
Bioaccumulation and Hepatic Speciation of Copper in Rainbow Trout (Oncorhynchus mykiss) During Chronic Waterborne Copper Exposure by Collins Kamunde; Ruth MacPhail (pp. 493-503).
To protect cells from toxicity, metal-sensitive cellular compartments must be insulated against essential but toxic metals [such as copper (Cu)] accumulated in excess of metabolic requirements. We measured Cu concentrations at the organ and hepatic subcellular levels in juvenile rainbow trout (Oncorhynchus mykiss) during exposure to sublethal waterborne Cu (40 μg/L) for 21 days. There was a time-dependent accumulation of Cu in the gill, liver, plasma, and carcass, with significant difference in Cu-exposed fish relative to the controls being evident by day 7. This significant accumulation of Cu was not associated with impaired growth. Copper concentrations in purity-tested liver subcellular fractions normalized to the liver protein concentration were in decreasing order: organelles > heat-stable proteins > nuclei-debris > NaOH-resistant granules > heat-labile proteins. As a proportion of the total, the majority of the hepatocellular Cu burden (60–68%) was associated with a metabolically active pool (organelles, nuclei-debris, and heat-stable proteins) and the remainder (32–40%) was associated with a metabolically detoxified pool (heat-stable proteins and NaOH-resistant granules) irrespective of the Cu-exposure regime. Because Cu concurrently accumulated in metabolically active and detoxified pools, we conclude that the spillover hypothesis of metal toxicity did not hold under the exposure conditions employed in this study. Moreover, these data suggest that rainbow trout can withstand significant above-background Cu accumulation in hepatic putative metal-sensitive compartments without chronic toxic effects at the organism level.
Keywords: Copper; Waterborne; Bioaccumulation; Internal speciation; Subcellular distribution; Rainbow trout
Biomagnification of Trace Elements in the Aquatic Food Web in the Mekong Delta, South Vietnam Using Stable Carbon and Nitrogen Isotope Analysis by Tokutaka Ikemoto; Nguyen Phuc Cam Tu; Noboru Okuda; Akihisa Iwata; Koji Omori; Shinsuke Tanabe; Bui Cach Tuyen; Ichiro Takeuchi (pp. 504-515).
In the present study, we report the concentrations of 21 trace elements (V, Cr, Mn, Co, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, Sn, Sb, Cs, Ba, Hg, Tl, Pb, and Bi), as well as the results of the analysis of stable carbon and nitrogen isotopes, of the various biota that make up the food web in the main stream of the Mekong Delta near Can Tho, South Vietnam. A significant trophic level-dependent increase was found in concentrations of Se, Rb, and Hg with increasing δ15N, indicating that an overall biomagnification of these elements occurred. However, the increase of Hg concentration per trophic level was lower than in previous studies. In contrast, the concentration of Mn showed an opposite trend in the food web of the Mekong Delta. In addition to these overall trends, the present study revealed that the biomagnification profiles of trace metals differ between crustaceans and fishes; concentrations of Mn, Cu, Zn, As, Sr, Mo, Ag, Cd, Sb, Cs, Ba, Tl, and Pb were significantly higher in crustaceans, whereas fishes showed higher concentrations of Cr, Rb, and Hg (trophic level determined by δ15N). The differences in the biomagnification profile between the major taxa might be attributed to differences in metal accumulation and in detoxification abilities such as possessing a metal-binding protein, e.g., metallothionein (MT).
Effects of Perchlorate on Growth and Behavior of a Granivorous Passerine, the Zebra Finch (Taeniopygia guttata) by Thomas R. Rainwater; Mary B. Wood; James R. Millam; Michael J. Hooper (pp. 516-524).
Perchlorate (ClO 4 − ) is a thyroid hormone inhibitor and persistent environmental contaminant that has been shown to impair thyroid function and growth in ground-dwelling birds. In this study, we used the zebra finch (Taeniopygia guttata) as a model to examine the effects of environmentally relevant perchlorate concentrations on growth and behavior of a granivorous passerine. On post-hatch days (PHDs) 3–14, finch chicks were orally dosed once per day with either 0, 10, 100, or 1000 μg sodium perchlorate/g body mass, and multiple endpoints of growth and behavior were examined in birds up to 72 days of age. Mean (±SE) body mass and tibiotarsal length were significantly reduced in the 100 and 1000 μg/g dose groups from PHDs 3–14, and this reduction persisted until PHD 40. Mean liver mass (PHD 15) in the 100 and 1000 μg/g dose groups were significantly greater than controls. Mean brain mass and mean nuclear volume of the song control nucleus area X in brains of 72-day-old males did not differ among dose groups. All endpoints of finch behavior were significantly influenced by perchlorate exposure at the highest dose level. Compared to controls, birds in this dose group exhibited a greater begging intensity, decreased motivation for spontaneous movement (e.g., attempts to fly), and reduced capacity to wean themselves from parental care. On PHD 15, flight attempts were also significantly reduced in the 10 and 100 μg/g dose groups, and the proportion of perchlorate-dosed birds attempting flight was less than half that in the control group. This study demonstrates a dose-dependent alteration of multiple growth and behavioral endpoints in zebra finches exposed to environmentally relevant concentrations of perchlorate. Comparable exposures in the wild may also affect normal development and behavior in similarly sensitive avian granivores.
Osprey Distribution, Abundance, Reproductive Success and Contaminant Burdens Along Lower Columbia River, 1997/1998 Versus 2004 by C. J. Henny; R. A. Grove; J. L. Kaiser (pp. 525-534).
The osprey (Pandion haliaetus) population nesting along the lower portion of the Columbia River (river mile 29 to 286) increased from 94 in 1997 to 103 occupied nests in 1998 (9.6% annual rate of increase) to 225 occupied nests in 2004 (13.9% annual rate of increase). The more recent rate of population increase was associated with higher reproductive rates than in 1997/1998, and significantly lower egg concentrations of most organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). A comparison of observed egg residue concentrations in 2004 with effect-level information for ospreys indicated that reproduction at few, if any, nests was adversely affected. As recent as 1997/1998, dichlorodiphenyldichloroethylene (DDE) was still adversely affecting reproductive success for a portion of this population. Mercury was the only contaminant evaluated in both 1997/1998 and 2004 that showed a significant increase in eggs over time, but concentrations in 2004 (0.09 μg g−1 ww) remained below established effect levels for birds (generally reported at 0.50 μg g−1 ww or higher). The significant increase in mercury justifies the need for future monitoring. All contaminants mentioned that biomagnify up food chains can be effectively monitored in osprey eggs. The osprey has been shown to be an excellent sentinel species for long-term monitoring with their many useful traits described.
Keywords: Osprey; Columbia River; Reproduction; Organochlorine pesticides; Dioxins; Furans; Polychlorinated biphenyls; Mercury
Acute and Chronic Effects of Perfluorobutane Sulfonate (PFBS) on the Mallard and Northern Bobwhite Quail by J. L. Newsted; Susan A. Beach; S. P. Gallagher; J. P. Giesy (pp. 535-545).
Perfluorobutane sulfonate (PFBS) can be a final degradation product of perfluorobutane sulfonyl fluoride (PBSF)-based chemicals. Surfactants based on this chemistry are potential replacements for perfluorooctane sulfonate (PFOS)-related products and have many potential applications in industrial and commercial processes and applications. To evaluate the potential hazard that PFBS may pose to avian species, acute dietary studies with juvenile mallards and northern bobwhite quail, as well as a quail dietary chronic study of reproduction were conducted. In the acute studies, 10-day-old mallards and quail were exposed to nominal dietary concentrations of 1,000, 1,780, 3,160, 5,620 or 10,000 mg PFBS/kg feed, wet weight (ww) for 5 days and the birds were then fed an untreated diet and observed for up to 17 days. No treatment-related mortalities were observed in the study up to 10,000 mg PFBS/kg, ww feed. Body weight gains of quail exposed to 5620 or 10,000 mg PFBS/kg feed were statistically less than that of unexposed controls. Weight gain of mallards exposed to 10,000 mg PFBS/kg feed was statistically less than that of controls. There were no statistically significant effects on feed consumption of either species. In the acute studies, no observed adverse effect concentration (NOAEC) for mallards and quail were 5620 and 3160 mg PFBS/kg, ww feed, respectively. In a reproduction study, adult quail were exposed to nominal dietary concentrations of 100, 300, or 900 mg PFBS/kg, ww feed for up to 21 weeks. There were no treatment-related mortalities or effects on body weight, weight gain, feed consumption, histopathology measures, or reproductive parameters evaluated in the study when compared to the control group. Concentrations of PFBS in blood serum, liver, and eggs were dose-dependent but were less than the administered dose, indicating biodiminution. Based on the results from the quail reproduction study, the dietary NOAEC was 900 mg PFBS/kg, ww feed (equivalent to an ADI of 87.8 mg PFBS/kg bw/d).
Total Mercury and Methylmercury Residues in River Otters (Lutra canadensis) from Wisconsin by Sean M. Strom (pp. 546-554).
The Wisconsin Department of Natural Resources (WDNR) collected trapper-caught river otter (Lutra canadensis) from 3 distinct areas of Wisconsin (north, central, and south). Otter carcasses were collected from a total of 12 counties during the trapping seasons of 2003 and 2004. Liver, kidney, muscle, brain, and fur tissue was collected for mercury (Hg) analysis. Analysis of variance identified collection zone as the significant factor for differences in tissue Hg levels, with a pattern of decreasing Hg concentrations from north to south (p < 0.0001). This trend was apparent in all tissue types analyzed. Strong relationships were observed between Hg concentrations in all tissues. Likewise, highly significant (p < 0.0001) relationships were found to exist between Hg concentrations in otter fur and Hg concentrations of internal organs (brain, muscle, kidney, and liver). Although these data suggest that Hg concentrations are related among tissues, they do not suggest uniform distribution of Hg throughout the tissues. The results suggest that Hg accumulates at higher concentrations in fur followed by liver, kidney, muscle, and brain. Analysis of a subset of samples for methylmercury (MeHg) revealed that MeHg made up a greater percentage of total Hg in brain and muscle compared to liver and kidney tissue. Although a gradient in tissue concentrations was observed from north to south, none of the tissue concentrations reached levels known to cause toxicity in either otter or mink.
The Use of Feathers to Monitor Heavy Metal Contamination in Herons, Korea
by Jungsoo Kim; Tae-Hoe Koo (pp. 555-555).