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Archives of Environmental Contamination and Toxicology (v.34, #2)
Distribution of Total Mercury and Methyl Mercury in Water, Sediment, and Fish from South Florida Estuaries by K. Kannan; R. G. Smith, Jr.; R. F. Lee; H. L. Windom; P. T. Heitmuller; J. M. Macauley; J. K. Summers (pp. 109-118).
Concentrations of total mercury and methyl mercury were determined in sediment and fish collected from estuarine waters of Florida to understand their distribution and partitioning. Total mercury concentrations in sediments ranged from 1 to 219 ng/g dry wt. Methyl mercury accounted for, on average, 0.77% of total mercury in sediment. Methyl mercury concentrations were not correlated with total mercury or organic carbon content in sediments. The concentrations of total mercury in fish muscle were between 0.03 and 2.22 (mean: 0.31) μg/g, wet wt, with methyl mercury contributing 83% of total mercury. Methyl mercury concentrations in fish muscle were directly proportional to total mercury concentrations. The relationship of total and methyl mercury concentrations in fish to those of sediments from corresponding locations was fish-species dependent, in addition to several abiotic factors. Among fish species analyzed, hardhead catfish, gafftopsail catfish, and sand seatrout contained the highest concentrations of mercury. Filtered water samples from canals and creeks that discharge into the Florida Bay showed mercury concentrations of 3–7.4 ng/L, with methyl mercury accounting for <0.03–52% of the total mercury. Consumption of fish containing 0.31 μg mercury/g wet wt, the mean concentration found in this study, at rates greater than 70 g/day, was estimated to be hazardous to human health.
Concentrations of Metals Associated with Mining Waste in Sediments, Biofilm, Benthic Macroinvertebrates, and Fish from the Coeur d'Alene River Basin, Idaho by A. M. Farag; D. F. Woodward; J. N. Goldstein; W. Brumbaugh; J. S. Meyer (pp. 119-127).
Arsenic, Cd, Cu, Pb, Hg, and Zn were measured in sediments, biofilm, benthic macroinvertebrates, and fish from the Coeur d'Alene (CDA) River to characterize the pathway of metals transfer between these components. Metals enter the CDA Basin via tributaries where mining activities have occurred. In general, the ranking of food-web components from the greatest to smallest concentrations of metals was as follows: biofilm (the layer of abiotic and biotic material on rock surfaces) and sediments > invertebrates > whole fish. Elevated Pb was documented in invertebrates, and elevated Cd and Zn were documented in sediment and biofilm approximately 80 km downstream to the Spokane River. The accumulation of metals in invertebrates was dependent on functional feeding group and shredders-scrapers that feed on biofilm accumulated the largest concentrations of metals. Although the absolute concentrations of metals were the largest in biofilm and sediments, the metals have accumulated in fish approximately 50 km downstream from Kellogg, near the town of Harrison. While metals do not biomagnify between trophic levels, the metals in the CDA Basin are bioavailable and do biotransfer. Trout less than 100 mm long feed exclusively on small invertebrates, and small invertebrates accumulate greater concentrations of metals than large invertebrates. Therefore, early-lifestage fish may be exposed to a larger dose of metals than adults.
Enhanced Heavy Metal Tolerance in Two Strains of Photosynthetic Euglena gracilis by Preexposure to Mercury or Cadmium by S. Devars; R. Hernández; R. Moreno-Sánchez (pp. 128-135).
The effects of different concentrations of Hg, Cd, and Pb on cell growth, oxygen consumption, and production and contents of chlorophyll a and b of Z and B strains of Euglena gracilis was studied. Cell uptake of Cd and Pb was also determined. A greater cell density reached in the presence of Cd2+ correlated with a lower metal uptake capacity in B-strain cells. Cells of Z strain, preexposed to low concentrations of either Hg2+ (1.5 μM) or Cd2+ (50 μM) for several generations showed improved heavy metal tolerance (greater cell density and viability) together with similar metal uptake capacity. Because Cd2+ preadaptation but not Hg2+ pretreatment induced a significant increase in the content of acid-soluble thiols, the data suggest the existence of different mechanisms of heavy metal detoxification in Euglena. The fact that Z-strain cells showed a greater Cd2+ uptake under all the conditions assayed suggests that Z strain would be more suitable for bioremediation of polluted waters.
Integrity of Lichen Cell Membranes in Relation to Concentration of Airborne Elements by J. Garty; N. Kloog; Y. Cohen (pp. 136-144).
This study dealt with the impact of air pollution on the integrity of cell membranes in the lichen Ramalina duriaei. The lichen was transplanted from a relatively unpolluted site in Israel to more polluted sites, adjacent to a 40-year-old town, for a period of 10 months. The concentrations of K, B, Al, Cr, Fe, Si, Ti, Zn, P, Ba, Cu, Mg, Na, Pb, Ca, Mn, Sr, and S in lichen thalli were compared with injury caused to the cell membranes. The study indicates that electric conductivity reflects adequately cellular injury to lichen thalli transplanted to sites near a motorway, an oil-fueled power plant and a rural community (a kibbutz). The concentrations of S, B, Al, Cr, Fe, Si, Ti, and Zn correlated with injury in cell membranes of R. duriaei retrieved from the biomonitoring sites, whereas the concentration of K in the thalli correlated inversely with the electric conductivity parameter. Leakage of K from lichen thalli as a result of air pollutants is suggested. This K leakage correlates positively with concentrations of S and Cr in transplants of R. duriaei to the Ashdod region.
Ecotoxicological Hazard Assessment of Two Polymers of Distinctively Different Molecular Weights by K. M. Jop; J. R. Allaway; P. R. Sampath; P. D. Guiney (pp. 145-151).
Assessment of ecological risks during manufacturing, use, transport, and disposal are becoming increasingly important as planning tools during development of new products. The objective of this study was to establish the potential ecotoxicological hazard associated with two polycarboxylate polymers in water, sludge, sediment, and soil. The concentrations of both polymers were quantified using 14C-radiolabeled synthesis and liquid scintillation counting (LSC). The program included water column acute and chronic exposures with Ceriodaphnia dubia, Pimephales promelas, and Selenastrum capricornutum, sediment exposures with Chironomus riparius, and soil exposures with Eisenia foetida. Sludge treated with either polymer, from a semicontinuous activated sludge unit, was used to evaluate the effect on growth of five plants.The hazard assessment program for both polymers indicated a very low order of toxicity as defined by the U.S. EPA and OECD. Very small fractions of each polymer may not be removed by waste treatment and could accumulate in sediments, but should not pose a significant risk because of their low toxicity to benthic organisms. Terrestrial testing demonstrated that soil needs to be saturated with these chemicals to produce adverse effects. Bioaccumulation potential for both polymers was extremely low. Use of these polymers does not appear to pose a significant risk to the environment, based on their low inherent toxicity.
Comparative Toxicity of Chlordane, Chlorpyrifos, and Aldicarb to Four Aquatic Testing Organisms by M. T. Moore; D. B. Huggett; W. B. Gillespie, Jr.; J. H. Rodgers, Jr.; C. M. Cooper (pp. 152-157).
Laboratory toxicity data contrasting responses of aquatic organisms to insecticides are important for focusing on sensitive species (steepest exposure-response slope) exposed to aqueous concentrations of these insecticides in field studies. These data also allow prediction of expected responses of aquatic species to a range of insecticide concentrations in situ. Aqueous 48-h toxicity tests were performed to contrast responses of Daphnia magna Straus, Hyalella azteca Saussure, Chironomus tentans Fabricius, and Pimephales promelas Rafinesque to acetylcholinesterase-inhibiting insecticides: chlorpyrifos, aldicarb, and chlordane. As expected, invertebrates tested (H. azteca, C. tentans, and D. magna) were ≥ 200 times more sensitive than the vertebrate P. promelas to chlorpyrifos exposures. H. azteca was approximately 3.5 times more sensitive to chlorpyrifos (453% mortality/μg/L) than D. magna (128% mortality/μg/L). For both aldicarb and chlordane, C. tentans was the most sensitive species tested (2.44 and 2.54% mortality/μg/L, respectively). Differences in chlordane potency for test species varied only by a factor of approximately 2–3 (0.88% mortality/μg/L for H. azteca to 2.54% mortality/μg/L for C. tentans). Although point estimates of population responses such as LC50s, NOECs, and LOECs are of some utility for predicting effects of pesticides in aquatic systems, exposure-response slopes are also useful for extrapolation of laboratory data to diverse field situations, especially where sediment sorption may regulate insecticide exposure or bioavailability.
Environmental Assessment of Benthic Impacts Associated with Pulp Mill Discharges. II. Distribution of Sediment EOX in Relation to Environmental Factors by P. K. Sibley; D. G. Dixon; D. R. Barton (pp. 158-166).
Between 1991 and 1992, comprehensive toxicological, chemical, and benthic community structure surveys were conducted at Jackfish Bay, Lake Superior, Ontario, to assess sediment quality below a bleached kraft mill effluent (BKME) outfall. In this report, we describe the spatial distribution and concentration of extractable organic chlorines (EOX) in sediments below the outfall in relation to effluent discharge patterns, sediment deposition, and bioaccumulation potential. Triplicate sediment samples were collected by Ekman grab from 29 and 44 stations in 1991 and 1992, respectively, and from 15 stations in three reference areas not exposed to the effluent. For each sample, organic carbon content, dry weight, and sediment-associated EOX were determined. In addition, sediment traps were used to determine sediment deposition along two tangents transecting the effluent plume and at a reference station located approximately 4,200 m from the outfall. The spatial distribution of sediment EOX consisted of two distinct concentration gradients, each linked to effluent discharge patterns from Blackbird Creek and dominant circulatory patterns in Jackfish Bay: a north–south gradient, extending along the west shore of Jackfish Bay, and a east–west gradient. Sediment EOX ranged from 7,000 mg/kg organic carbon (oc) (2,050 mg/kg dry solids (ds)) in depositional sediments of Moberley Bay to nondetectable at some stations in eastern and outer Jackfish Bay. Reference (background) concentrations ranged from nondetectable to 3,000 mg/kg oc (1–15 mg/kg ds). The attenuation of EOX was significantly correlated with the rate of sediment deposition (r2 = 0.57; p ≤ 0.001). Although the concentration of sediment EOX was strongly correlated with toxicity to some invertebrates (Sibley et al.[1997] Arch Environ Contam Toxicol 32:274–284), bioaccumulation factors were typically <2 based on analysis of oligochaete tissues. The results of this study demonstrate that the spatial distribution of sediment-associated contaminants adjacent to pulp mill effluent outfalls are determined primarily by hydrodynamic and depositional characteristics of the receiving waters and that EOX can be used to accurately delineate areas of contamination.
Tissue-Level Biomarkers in Sentinel Slugs as Cost-Effective Tools to Assess Metal Pollution in Soils by I. Marigómez; M. Kortabitarte; G. B. J. Dussart (pp. 167-176).
In previous laboratory experiments, slugs were shown to be sensitive to metal pollution. Therefore, they might be invaluable instruments for biological assessment of soil pollution. The present investigation was carried out to validate previous laboratory results in a field study. Slugs were collected from an abandoned copper mine (Parys mountain top, PMT), from a site 7 km away from the mine (Parys mountain bottom, PMB), and from a clean site (Snowdonia Cwm Idwal, SCI) in Wales in early July 1994. Whole soft body and digestive gland Cd, Cu, and Zn concentrations were measured by means of atomic absorption spectrophotometry (AAS). The digestive gland was the main tissue for metal accumulation, with significant differences in tissue metal levels between samples from different sites. PMB presented the highest Cd and Zn levels and the highest Cu levels were found at PMT. In addition, metals were demonstrated in situ by autometallography as black silver deposits (BSD) on histological sections of digestive gland tissue. The extent of BSD within lysosomes of digestive cells was closely related to metal levels determined by AAS. Histochemistry revealed that Ca metabolism and structural and reserve connective tissues might be altered in slugs living in metal-polluted soils. Finally, tissue-level biomarkers of biological effect [mean epithelial thickness (MET), mean diverticular radius (MDR), mean luminal radius (MLR), MET/MDR and MLR/MET] were quantified by image analysis of digestive gland histological sections stained with hematoxylin-eosin. MET and MDR values of slugs collected from SCI were high, while slugs from PMB presented low MLR/MET associated with environmental stress induced by metal exposure. We conclude that exposure and effect biomarkers recorded in sentinel slugs could be sensitive, quick, and cheap indices of metal pollution in soils. A Slug Watch monitoring program could be developed similar to the Mussel Watch program, which is currently applied to assess environmental quality in coastal and estuarine areas.
Effects of Dispersant Treatment on the Acute Aquatic Toxicity of Petroleum Hydrocarbons by M. M. Singer; S. George; I. Lee; S. Jacobson; L. L. Weetman; G. Blondina; R. S. Tjeerdema; D. Aurand; M. L. Sowby (pp. 177-187).
The acute effects of both untreated and dispersant-treated Prudhoe Bay crude oil on the early life-stages of three marine species were investigated. Identification of which water-accommodated fraction (undispersed or chemically dispersed) was considered “more toxic” was dependent on species, time, and endpoint (and by inference, test protocol). Generally, the data showed that at roughly equivalent hydrocarbon concentrations untreated oil solutions resulted in higher initial effects (< 1 h) in mysid and topsmelt tests, whereas dispersed oil solutions elicited higher levels of larval abnormality in abalone tests and higher levels of mortality in mysid tests. While differences in test protocols existed among the species tested, topsmelt were the most sensitive species to untreated oil solutions, with mysids being most sensitive to dispersed oil solutions.
Preliminary Observations on Responses of Embryonic and Larval Pacific Herring, Clupea pallasi, to Neutral Fraction Biodegradation Products of Weathered Alaska North Slope Oil by D. P. Middaugh; M. E. Shelton; C. L. McKenney, Jr.; G. Cherr; P. J. Chapman; L. A. Courtney (pp. 188-196).
Weathered Alaska North Slope crude oil (ANS 521) was subjected to biodegradation in vigorously stirred incubations for 14 days at 15 ± 1°C in 20‰ salinity sterilized seawater, amended with nutrients and inoculated with a hydrocarbon-degrading microorganism (EI2V) isolated from an oil-contaminated beach in Prince William Sound, Alaska. A total of 13.7 mg/L water-soluble neutral fraction (WSF) was recovered from the incubation of weathered ANS 521. Toxicity/teratogenicity tests were conducted with WSF recovered from the biodegradation system using embryonic and larval Pacific herring, Clupea pallasi. Exposures were begun at 4, 48, and 96 h postfertilization of herring eggs. Exposure concentrations were 1, 10, and 100% of the original concentration of WSF recovered from incubations (redissolved in 20‰ salinity sterile seawater at 15 ± 1°C). Sterile 20‰ salinity seawater without the addition of redissolved neutral fraction was used as a control. Significant (p ≤ 0.05) embryo mortality or teratogenic responses were observed at WSF concentrations of 10 and 100%. On days 5 through 8 of embryogenesis, counts of heart contraction rates were significantly lower (p ≤ 0.05) at the 100% WSF concentration for embryos exposed beginning at 4 and 48 h postfertilization. Grow-out of larvae from selected exposures was conducted. High mortality was noted in larvae exposed to the 10% WSF concentration beginning at 4 and 48 h postfertilization. Most of these larvae died 5 to 8 days after hatching when they elicited vertebral displacements at a time concurrent with the onset of feeding behavior.
Trace Element Concentrations in Two Subpopulations of Lesser Snow Geese from Wrangel Island, Russia by A. Hui; J. Y. Takekawa; V. V. Baranyuk; K. V. Litvin (pp. 197-203).
Lesser snow geese (Anser c. caerulescens) from the Wrangel Island, Russia breeding colony spend the winter in two widely separated areas: the northern subpopulation in southern British Columbia and northern Washington and the southern subpopulation in the Central Valley of California. We examined 19 trace elements in the eggs and livers of geese from these two subpopulations to examine whether geese from the different wintering areas have similar trace element burdens. Eggs collected at the breeding colony from geese of the southern subpopulation had slightly higher levels of manganese, an element that can cause neurological damage and behavioral changes in chicks, than geese of the northern subpopulation. Livers from adult geese collected on the two wintering areas showed significant differences in trace elements including copper, iron, magnesium, molybdenum, and zinc. Copper concentrations in the livers of geese from the southern subpopulation were much higher than those from the northern subpopulation (x¯ = 116 vs. 46 ppm; dry weight). Elevated levels of copper may induce anemia in birds. The differences in trace element concentrations of these two subpopulations may be related to farming practices in their wintering areas. Geese from the northern subpopulation feed in pastures and coastal marshes and migrate along the coast, but geese from the southern subpopulation feed predominantly in rice fields and migrate over farm land. Copper and manganese are major components of fertilizers and fungicides commonly applied during rice cultivation.
Pre- and Postnatal Exposure to 3,3′,4,4′-Tetrachlorobiphenyl: I. Effects on Breeding Ability and Sperm Fertilizing Ability in Male Mice by A. Huang; D. Powell; K. Chou (pp. 204-208).
This study investigated the effects of 3,3′,4,4′-tetrachlorobiphenyl (TCB) on the reproductive performance and in vitro sperm fertilizing ability of male mice. C57BL/6J female mice (F-0) were fed diets containing 0, 3, or 30 ppm TCB for 2 weeks before pairing with nontreated males for a 10-day breeding period. Females were continued on their treatment diet throughout mating, gestation, and lactation. Male offspring (F-1) were given the same diet as their dams throughout this study. F-1 males at 7 and 17 weeks of age were mated to nontreated B6D2-F1 female mice. Body weight, litter size, and survival indices of offspring sired by F-1 males were recorded. Sperm fertilizing ability of F-1 males at 9 and 19 weeks of age was examined in vitro using eggs collected from nontreated B6D2-F1 females. Sperm motion analysis was performed at the same time. When 7- and 17-week-old F-1 males were mated to nontreated females, no differences in fecundity, litter size, sex ratio, or survival indices among any of the treatments were observed. However, sperm fertilizing ability of 30 ppm–treated F-1 males at 19 weeks of age was less than that of the control mice. Testes weights were greater in 3-week-old, 30 ppm–treated mice.
Pre- and Postnatal Exposure to 3,3′,4,4′-Tetrachlorobiphenyl: II. Effects on the Reproductive Capacity and Fertilizing Ability of Eggs in Female Mice by A. Huang; S. Lin; R. Inglis; D. Powell; K. Chou (pp. 209-214).
This study investigated the effects of 3,3′,4,4′-tetrachlorobiphenyl (TCB) on the reproductive capacity of female mice. Female C57BL/6J mice (F-0) were fed diets containing 0, 3, or 30 ppm TCB for 2 weeks before pairing with nontreated C57BL/6J males for a 10-day breeding period. Females were continued on their treatment diet throughout mating, gestation, and lactation. Female offspring (F-1) were fed the same diet as their dams throughout the study. The reproductive capacity of F-1 females was examined by mating with non-treated B6D2-F1 males. In addition, the fertilizing ability of eggs from F-1 females was examined in vitro by insemination with sperm from nontreated B6D2-F1 males. Fecundity in F-0 females after mating was 80%, 71%, and 47% in the 0, 3, and 30 ppm treatment groups, respectively. Four-day and 21-day survival indices were lower for offspring of 30 ppm TCB-treated F-0 females than for offspring of the control females. Fecundity in F-1 females was the same among all treatment groups, however, all offspring born to 3- and 30-ppm TCB-treated F-1 females died before 4 days of age. Although the litter size at birth was not affected, the in vitro fertilizing ability of eggs in the 3- and 30-ppm treatment groups was lower than in the control group. This decrease in fertilizing ability was associated with an increase in degenerated eggs. F-0 females treated with 30 ppm TCB had enlarged livers during pregnancy and lactation. At 5 and 6 weeks, liver enlargement and thymus atrophy were apparent in F-1 females exposed to 30 ppm TCB. This study demonstrated impaired reproductive capacity and decreased egg fertilizing ability in TCB-treated female mice.
