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Archives of Environmental Contamination and Toxicology (v.34, #4)
The Extent of Benthic Impacts of CCA-Treated Wood Structures in Atlantic Coast Estuaries by J. S. Weis; P. Weis; T. Proctor (pp. 313-322).
To ascertain the extent of impacts from CCA-treated wood bulkheads, we sampled sediments along 10-m transects from these bulkheads and from reference sites (either bulkheads made of other materials or unbulkheaded areas nearby) and analyzed the fine fraction for metals. We ascertained metal content in resident biota, and analyzed species richness, Shannon-Wiener diversity index, and biomass of the benthic community. We found accumulation of metals in the fine-grained portion of nearby sediments and reduction in the biotic community nearby (generally at 0 and 1 m); such gradients were generally not seen in reference transects. At two of the sites there was evidence for secondary reduction of the community out further to 3 or 10 m, where the metals in the fines were lower but the percent fines was greatly increased. At all the other sites, impacts were generally limited to 0 and 1 m. The lack of reduction at further distances at the other sites is attributed to factors such as the age of the bulkheads, high energy of the environment, or nature of the sediments at those sites.
The Fate of Elements in Residential Composters by G. J. Evans; P. V. Tan (pp. 323-329).
An investigation into the fate of elements during residential composting was conducted by studying an Envirocycle residential-type aerobic composter unit that was set up and operated at the University of Toronto's greenhouse facility. Source materials consisting of various fruits and vegetables were combined with Metropolitan Toronto Works Department's finished leaf compost (MWFLC), and composted over a 2-month period. Instrumental neutron activation analysis (INAA) was used to determine the concentrations of Al, As, Ba, Ca, Co, Cr, Fe, K, Mg, Mn, Na, Sb, Sr, Ti, V, and Zn in the source materials and the 2-month greenhouse finished compost (GHFC). Results indicate that the ratio of final element mass to input element mass was approximately 1, suggesting that elements are conserved during the composting process. One tailed t tests (0.05 level of significance) on element concentrations between the MWFLC and GHFC revealed that supplementing MWFLC with fruits and vegetables does not significantly change concentrations >25%. One-way analyses of variances conducted on Toronto residential compost samples revealed good homogeneity within an individual composter, although significant elemental variances occurred between separate composters. Incidentally, it was noticed that several of the Toronto residential compost samples had Cr levels that exceeded Ontario Ministry of Environment and Energy guideline values for municipal compost.
Lead Content in Edible Wild Mushrooms in Northwest Spain as Indicator of Environmental Contamination by M. A. García; J. Alonso; M. I. Fernández; M. J. Melgar (pp. 330-335).
Lead content was determined in wild growing mushrooms collected from two different areas in the Province of Lugo (NW Spain). It has been analyzed by graphite furnace atomic absorption spectrometry in 95 samples of 13 species (7 mycorrhizals and 6 saprophites). In an assessment of lead concentrations, the following factors have been considered: species and ecology, morphological portion, and traffic pollution. The average lead concentration of the samples was 1 ppm dry weight (dw). Saprophite species presented higher levels than mycorrhizal ones (<1 ppm), Coprinus comatus reaching the maximum mean concentration with 2.06 and 2.79 ppm of dw in the hymenophore and the rest of the fruit body. Morphological portion, statistically, did not show significant difference between the two portions; however, Macrolepiota procera always presented lead high levels in the hymenophore in all samples. The effect due to traffic pollution has been specially observed in Coprinus comatus, presenting the highest concentration with values of 6.51 and 10.43 ppm, respectively, in samples collected in the city center. This species, as other researchers have indicated, could be considered as an indicator by lead contamination. The contribution of mushrooms to the weekly intake of lead was calculated and the posible health risk for the consumer is pointed out. These data are of great importance in view of toxicology and partly environmental protection.
In Situ Investigation of Trace Metal Availability in Industrial Effluents Using Transplanted Aquatic Mosses by J. Mersch; M. Reichard (pp. 336-341).
Three species of aquatic mosses, Rhynchostegium riparioides, Fontinalis antipyretica, and Cinclidotus danubicus, were collected from the same reference location and exposed in five industrial effluents. The purpose was to test their suitability for assessing trace metal contamination under adverse and contrasted environmental conditions. Two distinct experiments of 16 and 11 days were conducted. In spite of short residence times in the effluents, the bryophytes were considerably affected at several sites, showing a light green to yellowish color, brown-edged leaves, and even dead strands. Cinclidotus danubicus was the most resistant whereas Fontinalis antipyretica was the most sensitive species. The observed physiological damage had no obvious incidence on the accumulation capacity of the mosses. The biomonitors provided time-integrated patterns of trace metal bioavailability (copper, chromium, nickel, lead, and zinc) in the effluents with a clear discrimination between poorly, moderately, and heavily polluted sites. Compared to water analyses, these more reliable indications could be obtained with a considerably reduced sampling design. When substantial accumulation occurred in mosses, the highest concentrations were systematically found in Rhynchostegium riparioides and the lowest in Cinclidotus danubicus. As only quantitative, not qualitative, differences were observed, all investigated moss species can be recommended for the assessment of trace metals in effluents at their discharge into the natural environment.
Inertia and Resilience in the Responses of the Aquatic Bryophyte Fontinalis antipyretica Hedw. to Thermal Stress by A. Carballeira; S. Díaz; M. D. Vázquez; J. López (pp. 343-349).
The physiological responses of the aquatic bryophyte Fontinalis antipyretica Hedw. to high temperatures, ranging from 16°C (control) to 34°C, were investigated experimentally. Plant samples were maintained at the temperature under study for up to 25 days with regular determination of physiological variables (pigment ratio and photosynthetic and respiratory rates). Physiological responses to temperature did not differ significantly between mosses collected from a normal river site and from a river site with abnormally high temperature due to input from a hot spring. Simple curve-fitting procedures and summary statistics analogous to those used in toxicological research were employed to compare responses as revealed by the different physiological variables. In a second series of experiments, the capacity of F. antipyretica to recover from high-temperature stress was investigated by maintaining samples at 30°C for 2, 4, or 10 days, then transferring the samples to normal conditions (16°C) for 40 days. Physiological variables were again monitored at regular intervals throughout both phases of the experiment. In general, good recovery was observed even after exposure to high temperatures for 10 days. The results of these assays allow quantification of the relationship between a pigment ratio and net photosynthesis rate.
Ecotoxicity Assessment of Contaminated Dredged Material with the Marine Amphipod Corophium volutator by S. Ciarelli; W. A. P. M. A. Vonck; N. M. van Straalen; J. Stronkhorst (pp. 350-356).
The incorporation of toxicological data from bioassays can improve the present system of sediment quality criteria in the Netherlands. The use of acute lethality toxicity tests alone does not however provide sufficient discrimination and sensitivity for predicting ecological effects of slightly and moderately contaminated dredged material. Sublethal endpoints are needed for the assessment of environmental hazards of such dredged material. In this study, two approaches were used to identify toxicity of marine sediments collected from 16 locations classified as “slightly and moderately contaminated” on the basis of chemical data: (1) a comparison of growth vs. mortality as different endpoints in the marine amphipod Corophium volutator (Pallas); (2) an investigation on the use of sediment dilutions to characterize the degree of toxicity. The influence of sediment storage time on toxicity was also evaluated. In four out of 16 locations, mortality over 10 days of exposure ranged 80–100%; in two out of 16 locations mortality ranged 40–60%. In the other 10 locations, mortality was below 15%. Results on growth showed that in all locations final dry weight values were significantly lower (a factor of 1.5 to 3) than in controls. Results of dilution experiments showed that if sediments were diluted with a reference sediment of similar physicochemical characteristics, total concentrations of metals, mineral oil, and PAHs decreased as expected and so did the effects on C. volutator. In the 100% contaminated sediments growth was reduced by 32–60% compared to controls. The dilution rate necessary to reduce toxicity to the EC10 value for growth of C. volutator was considered an appropriate endpoint for the evaluation. When sediments were stored for a period of 3–5 months at 4°C and retested, effects on mortality and growth decreased, although some effects on growth were still measured after 5 months of storage. The experiments illustrate the usefulness of ecotoxicity assessment to evaluate contaminted dredged material.
Bioassays Using the Midge Chironomus riparius and the Zebra Mussel Dreissena polymorpha for Evaluation of River Water Quality by S. C. Stuijfzand; A. Drenth; M. Helms; M. H. S. Kraak (pp. 357-363).
To evaluate if the water quality of the river Meuse affects macrofauna species, the impact of water from this river on two representative species was tested under controlled conditions. Short-term bioassays with reference populations of the midge Chironomus riparius and the zebra mussel Dreissena polymorpha were performed simultaneously, using growth and filtration rate as sublethal parameters, respectively. Filtration rates of mussels seemed to be slightly inhibited by Meuse water in 1994 and 1995, although this was only significant in the first year. Apparently, although this species is inhabiting the river Meuse, the water quality still causes sublethal effects. In contrast to the mussel, midges were less sensitive to Meuse water in laboratory experiments; growth inhibition was never observed, while in some experiments growth was even enhanced. In the period of testing, it was not possible to relate effects on macrofauna species in laboratory tests to individual substances in polluted river systems. Because the response of the test species was marginal, it is recommended to include more sensitive species as tested in the present study, especially in view of a general improvement of the water quality in the river Meuse.
Paraquat Tolerance and Alteration of Internal Gill Structure of Scinax nasica Tadpoles (Anura: Hylidae) by R. C. Lajmanovich; M. F. Izaguirre; V. H. Casco (pp. 364-369).
Paraquat acute tolerance, and histological and ultrastructural response analysis of gills were evaluated in Scinax nasica tadpoles at stages 25–26. The treated tadpoles were able to survive with a mortality rate similar to the controls in media containing 6.48 to 10.80 mg PQ/L. At 18.00 mg PQ/L survival rate was about 85%; at 30.00 and 50.00 mg PQ/L an incremented mortality rate was detected. Their internal gills appear to have a critical role in adaptation to exposure to PQ. The LC-50 values found helped us conclude that increasing time of exposure to PQ produces a decrease of tadpole survival rate. With light microscopy, the apical ramification gill tufts exhibited a dose response increase of the total volume. At the ultrastructural level, an increase in the intercellular spaces and alteration in gill epithelium organization were the most notable changes. Furthermore, the capillaries showed enlarged endothelial cells, irregular nuclei, and numerous cytoplasmatic projections.
Comparative Toxicity of Diuron on Survival and Growth of Pacific Treefrog, Bullfrog, Red-Legged Frog, and African Clawed Frog Embryos and Tadpoles by G. S. Schuytema; A. V. Nebeker (pp. 370-376).
The effects of the herbicide diuron on survival and growth of Pacific treefrog (Pseudacris regilla), bullfrog (Rana catesbeiana), red-legged frog (Rana aurora), and African clawed frog (Xenopus laevis) embryos and tadpoles were determined in static-renewal tests. P. regilla and X. laevis embryos had reduced growth and developed increased deformities in diuron concentrations over 20 mg/L. Hindlimb bud and forelimb development were retarded in R. aurora following 14 days exposure to diuron concentrations of > 7.6 mg/L. Mean 14-day LC50s for P. regilla and X. laevis tadpoles were 15.2 and 11.3 mg/L diuron, respectively. The 21-day LC50 for R. catesbeiana tadpoles was 12.7 mg/L diuron. The 14-day LC50 for R. aurora tadpoles was 22.2 mg/L. The lowest NOAELs calculated in embryo tests were 14.5 mg/L for P. regilla (10 days) and 7.6 mg/L diuron for X. laevis (4 days). The lowest NOAELs calculated in tadpole tests were: P. regilla, 14.5 mg/L (14 days); R. catesbeiana, 7.6 mg/L (21 days); R. aurora, 7.6 mg/L (14 days); and X. laevis, > 29.1 mg/L (14 days). Diuron concentrations having an effect on survival, growth, and malformation in the laboratory were much higher than those found in normal field spray situations; field studies would be needed to determine the hazard to amphibians in areas of localized pooling of recently applied herbicide in the environment.
Effects of Subchronic Exposure to Cadmium Chloride on Endocrine and Metabolic Functions in Rainbow Trout Oncorhynchus mykiss by A. C. Ricard; C. Daniel; P. Anderson; A. Hontela (pp. 377-381).
Adult and juvenile rainbow trout, Oncorhynchus mykiss, were exposed for 30 days to CdCl2 in water (10 and 25 μg Cd/L for adults, and 1 and 5 μg Cd/L for juveniles) to investigate effects of subchronic exposures to Cd on the hypothalamo-pituitary-interrenal and the hypothalamo-pituitary-thyroid axis, and on metabolic status. Liver size and glycogen content and body mass gain were significantly reduced in the exposed adult fish and similar changes were detected in the juveniles. Plasma cortisol levels increased after exposure to the lower dose but decreased at the higher dose. Plasma T3 and T4 tended to decrease in the exposed adult fish. No significant differences in plasma glucose or cholesterol levels were detected between the controls and the exposed fish, plasma calcium levels were lower in the exposed fish. The results indicate that long-term exposures to Cd at sublethal doses have adverse effects on the physiological status of the fish and that these effects are mediated partly through alterations of endocrine function.
Trace Elements in Egg Contents and Egg Shells of Slider Turtles (Trachemys scripta) from the Savannah River Site by J. Burger; J. W. Gibbons (pp. 382-386).
In this paper we examine the levels of trace elements in the egg contents and egg shells of slider turtles (Trachemys scripta) from the Savannah River Site, near Aiken, South Carolina. Trace elements have seldom been examined in the tissues or eggs of reptiles, although some turtles and large snakes occupy a high trophic level. Lead, mercury, cadmium, selenium, chromium, and manganese levels were examined in one egg and its egg shell collected from each of 16 females that laid in late May and June 1996. We were interested in determining background levels, whether certain metals were sequestered in the egg shells, and whether levels were higher in contents or shells. Concentrations were higher in egg contents than in shells for lead, mercury, and selenium, while chromium was higher in the shell. There were no differences for cadmium and manganese. Compared to eggs from other reptiles, levels in slider turtles were generally similar for cadmium and selenium, lower for chromium and lead, and higher for manganese.
Accumulation Features of Polychlorinated Biphenyls and Organochlorine Pesticides in Resident and Migratory Birds from South India by S. Tanabe; K. Senthilkumar; K. Kannan; A. N. Subramanian (pp. 387-397).
Persistent organochlorines such as DDT and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), chlordane compounds (CHLs), hexachlorobenzene (HCB), and polychlorinated biphenyls (PCBs) were determined in whole-body homogenates of resident and migratory birds collected from South India. Organochlorine contamination pattern in birds varied depending on their migratory behaviour. Resident birds contained relatively greater concentrations of HCHs (14–8,800 ng/g wet wt) than DDTs and PCBs concentrations. In contrast, migrants exhibited elevated concentrations of PCBs (20–4,400 ng/g wet wt). The sex differences in concentrations and burdens of organochlorines in birds were pronounced, with females containing lower levels than males. Inland piscivores and scavengers accumulated greater concentrations of HCHs and DDTs while coastal piscivores contained comparable or greater amounts of PCBs. Global comparison of organochlorine concentrations indicated that resident birds in India had the highest residues of HCHs and moderate to high residues of DDTs. It is, therefore, proposed that migratory birds wintering in India acquire considerable amounts of HCHs and DDTs. Estimates of hazards associated with organochlorine levels in resident and migratory birds in India suggested that Pond Heron, Little Ringed Plover, and Terek Sandpiper may be at risk from exposure to DDTs.
Dietary Exposure to Mercury in Nestling Wood Storks (Mycteria americana) in Georgia by J. C. Gariboldi; C. H. Jagoe; A. L. Bryan, Jr. (pp. 398-405).
The United States breeding population of the wood stork (Mycteria americana) was listed as endangered in 1984; the U.S. Fish and Wildlife Service has listed the determination of potential contaminant hazards as a task important to the recovery of the species. Storks nest in colonies and adult storks forage over wide areas and return with prey items to feed to nestlings. The most recently consumed prey items are usually regurgitated by nestlings when they are handled. In 1995, over 200 food items from four wood stork colonies were collected while banding nestlings between 20 and 40 days old, and total mercury determined in individual food items. Two colonies were located on the Atlantic coast and two in inland areas. Overall dietary mercury concentration for each colony was calculated based on the biomass of each type of food item within the diet. Freshwater prey items had higher mercury concentrations than saltwater items most frequently chosen by storks. Daily Hg doses were estimated for a range of nestling sizes and daily food consumption rates. Risk factors were calculated based on two lowest observable adverse effect concentrations (LOAECs) from previous avian mercury ingestion studies. Based on one LOAEC, all four colonies in this study were at risk of sublethal effects due to mercury in the diet of nestling wood storks. More extensive studies of sublethal effects in avian species from mercury contamination are necessary for more accurate risk assessment.
Organochlorine and Heavy Metal Contaminants in Wild Mink in Western Northwest Territories, Canada by K. G. Poole; B. T. Elkin; R. W. Bethke (pp. 406-413).
The mink (Mustela vison) is a top trophic level species that readily bioaccumulates environmental pollutants and is considered to be a sensitive indicator of ecosystem health. Spatial trends in levels of organochlorine and heavy metal contaminant burdens were determined from 1991 to 1995 for wild mink from western Northwest Territories (NWT), Canada. Tissue samples from 207 mink from seven communities were analyzed for residues of 63 organochlorines and 10 heavy metals. All groups of organochlorines were detected in mink livers at relatively low levels; maximum community means were 9.52 ng/g ΣDDT and 73.07 ng/g ΣPCB (sum of 43 congeners). There was a general trend of decreasing organochlorine burdens along a northerly or westerly gradient for some groups of compounds, primarily ΣDDT, ΣPCB, Σchlordane and dieldrin. Toxic equivalents (TEQs) of mink liver tissue were low, with the maximum community mean of 0.28 pg/g wet weight (5.5 pg/g lipid weight). Levels of heavy metal burdens in liver and kidney tissues were found to be relatively low, with the exception of Hg, which was found at moderate levels. There was no obvious geographic trend to the pattern of heavy metal burdens. The available evidence suggests that long-range atmospheric transport is the main source of the organochlorine contaminants observed. Local conditions (geology, water and soil chemistry, diet, etc.) may determine heavy metal burdens. Levels of contaminants in NWT mink appear to be one to two orders of magnitude lower than levels observed to cause reproductive impairment, reduced survival of kits, or lethality in adult mink. In the western NWT mink may be the best indicator to assess trends in environmental contaminants and ecosystem health; periodic monitoring is recommended.
Polychlorinated Naphthalenes and Other Organochlorine Contaminants in Swedish Human Milk, 1972–1992 by Å. Lundén; K. Norén (pp. 414-423).
The concentrations of polychlorinated naphthalenes (PCNs) were determined together with polychlorinated biphenyls (PCBs), dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), 1,1-bis-(4-chlorophenyl)-2,2,2-trichloroethane (p,p′-DDT), 2,2-bis(4-chlorophenyl)-1,1-dichloroethylene (p,p′-DDE) and hexachlorobenzene (HCB) in milk, sampled in the course of 1972–92 from mothers living in Stockholm. A previously developed method for multicomponent analysis of organochlorine environmental contaminants was adapted for simultaneous analysis of PCNs. The mean recoveries of seven chlorinated naphthalene (CN) congeners added to milk prior to extraction were 76–99%. Similar recoveries were obtained for the commercial PCN product Halowax 1014. The pattern of PCNs in milk differed to a great extent from that in the commercial PCN products. The dominating congeners in breast milk were 1,2,3,5,7-pentachloronaphthalene (CN-52), 1,2,3,4,6,7- and/or 1,2,3,5,6,7-hexachloronaphthalene (CN-66/CN-67) and one unidentified tetrachloronaphthalene. There was a notable decrease in the concentrations of PCNs as was of the other organochlorine contaminants in milk from 1972 to 1992. During this time period the sum of CN congeners decreased from 3,081 to 483 pg/g milk fat and the sum of toxic equivalents of dioxin and dioxin-like compounds decreased from 100 to 39 pg/g milk fat.