| 1. |
- Bertling, Sofia, et al.
(författare)
-
Long-term corrosion-induced copper runoff from natural and artificial patina and its environmental impact
- 2006
-
Ingår i: Environmental Toxicology and Chemistry. - 0730-7268 .- 1552-8618. ; 25:3, s. 891-898
-
Tidskriftsartikel (refereegranskat)abstract
- The overall objective of this paper is to present an extensive set of data for corrosion-induced copper dispersion and its environmental interaction with solid surfaces in the near vicinity of buildings. Copper dispersion is discussed in terms of total copper flows, copper speciation and bioavailability at the immediate release situation, and its changes during transport from source to recipient. Presented results are based on extensive field exposures (eight years) at an urban site, laboratory investigations of the runoff process, published field data, generated predictive site-specific runoff rate models, and reactivity investigations toward various natural and manmade surfaces, such as those in soil, limestone, and concrete. Emphasis is placed on the interaction of copper-containing runoff water with different soil systems through long-term laboratory column investigations. The fate of copper is discussed in terms of copper retention, copper chemical speciation, breakthrough capacities, and future mobilization based on changes in copper concentrations in the percolate water, computer modeling using the Windermere Humic Aqueous Model, and sequential extractions. The results illustrate that, for scenarios where copper comes in extensive contact with solid surfaces, such as soil and limestone, a large fraction of released copper is retained already in the immediate vicinity of the building. In all, both the total copper concentration in runoff water and its bioavailable part undergo a significant and rapid reduction.
|
|
| 2. |
- Bertling, Sofia, et al.
(författare)
-
Model studies of corrosion induced copper runoff fate in soil
- 2006
-
Ingår i: Environmental Toxicology and Chemistry. - 0730-7268 .- 1552-8618. ; 25:3, s. 683-691
-
Tidskriftsartikel (refereegranskat)abstract
- Laboratory experiments have been performed with 3-cm soil columns simulating the fate of corrosion-induced copper runoff in contact with soil. The investigation simulates approximately 30 years (assuming an infiltration surplus of 25 cm/year) of continuous percolation of copper containing runoff water of a concentration realistic at the immediate release situation (4.8 mg/L) into four soils representative of urban conditions. Two of the three investigated topsoils reached their breakthrough of copper within the simulated time, while the third topsoil did not show a breakthrough. The subsoil reached a breakthrough after approximately 10 years of simulated exposure. To simulate more realistic outdoor scenarios, the laboratory-obtained breakthrough curves were modeled with Hydrus-1D (R) using a Langmuir-Freundlich model to describe copper sorption, the parameters of which were estimated from soil properties (pH, organic carbon content). The model predicts longer breakthrough times with increasing pH and organic content of the soil and with decreasing concentrations of copper and dissolved organic carbon in the runoff water. The time span for copper in runoff water (at concentrations of 0.01-10 mg/L) to reach a soil depth of 50 cm varied between 170 and more than 8,000 years for the predicted field scenarios.
|
|
| 3. |
- Holm, Lena, et al.
(författare)
-
Embryonic exposure to o,p'-DDT causes eggshell thinning and altered shell gland carbonic anhydrase expression in the domestic hen
- 2006
-
Ingår i: Environmental Toxicology and Chemistry. - 0730-7268 .- 1552-8618. ; 25:10, s. 2787-2793
-
Tidskriftsartikel (refereegranskat)abstract
- The mechanism for contaminant-induced eggshell thinning in wild birds remains to be clarified. It is generally assumed, however, that it results from exposure of the adult laying female. We have reported that embryonic exposure to the synthetic estrogen ethynylestradiol (EE2) results in eggshell thinning in the domestic hen. The objective of this study was to investigate whether eggshell thinning can be induced following in ovo exposure to a bioaccumulating estrogenic environmental contaminant, o,p '-DDT. Ethynylestradiol was used as a positive control. Domestic hens exposed in ovo to o,p '-DDT (37 or 75 mu g/g egg) or EE2 (60 ng/g egg) laid eggs with thinner shells than the control birds. The hens from these exposure groups also had a significantly reduced frequency of shell gland capillaries with carbonic anhydrase (CA) activity, a key enzyme in eggshell formation. The decreased number of capillaries with CA activity suggests that a developmentally induced disruption of CA expression in the shell gland was involved in the eggshell thinning found in this study. Egg laying was not affected in hens exposed embryonically to 37 or 75 mu g o,p '-DDT/g egg, whereas it was inhibited in hens exposed to higher doses. Decreased lengths of the left oviduct and its infundibulum were seen after embryonic treatment with o,p '-DDT or EE2. In addition, o,p '-DDT exposure resulted in right oviduct retention. The results support our hypothesis that eggshell thinning in avian wildlife can result from a functional malformation in the shell gland, induced by embryonic exposure to estrogenic substances.
|
|
| 4. |
- Jacobson, Therese, et al.
(författare)
-
Reproductive effects of the endocirne disruptor fenarimol on a baltic amphipod Monoporeia affinis
- 2006
-
Ingår i: Environmental Toxicology and Chemistry. - 0730-7268 .- 1552-8618. ; 25:4, s. 1126-1131
-
Tidskriftsartikel (refereegranskat)abstract
- An endocrine disruptor, the fungicide fenarimol, was investigated regarding its effects on reproduction and hormone (ecdysteroid) levels in the deposit-feeding amphipod Monoporeia affinis. In addition, the influence of food shortage, both by itself and in combination with fenarimol, on reproduction was examined. Field-collected amphipods were exposed in flow-through microcosms during the period of sexual maturation and mating in four treatment series: Control with low food, fenarimol with low food, control with high food, and fenarimol with high food. Fenarimol was added at a concentration of 0.3 mg/L in two pulses/week. Results show that fenarimol has a negative effect on fertilization rate and male mating ability. Results were supported by a tendency toward delayed male sexual development. Food shortage decreased weight in both sexes and retarded female oocyte development. Higher ecdysteroid levels were recorded in males than in females, and food shortage increased male ecdysteroid levels. No effect of fenarimol exposure on ecdysteroid levels was observed. No synergistic effects of fenarimol and food shortage could be distinguished in any variable examined. Thus, M. affinis was vulnerable to reproductive impairment by fenarimol, with effects on the next generation (i.e., a disturbed sexual development and fertilization ability). Food shortage has negative effects on M. affinis, but it does not enhance the effects of fenarimol.
|
|
| 5. |
- Johansson, Markus, et al.
(författare)
-
Toxicity of six pesticides to common frog (Rana temporaria) tadpoles
- 2006
-
Ingår i: Environmental Toxicology and Chemistry. - 0730-7268 .- 1552-8618. ; 25:12, s. 3164-3170
-
Tidskriftsartikel (refereegranskat)abstract
- Amphibian species inhabiting agricultural areas may be exposed to pesticides during their aquatic larval phase. We tested the toxicity of six commonly used pesticides on Rana temporaria spawn and tadpoles. In acute tests, tadpoles were exposed to relatively high concentrations of azoxystrobin, cyanazine, esfenvalerate, MCPA ([4-chloro-2-methylphenoxyl acetic acid), permethrin, and pirimicarb for 72 h. Chronic exposure tests were performed from fertilization to metamorphosis with azoxystrobin, cyanazine, and permethrin at concentrations similar to those found in surface waters in agricultural areas in Sweden. The most lethal pesticides in the acute exposure were azoxystrobin, permethrin, and pirimicarb. Also, negative effects on the growth of the tadpoles were observed with azoxystrobin, cyanazine, and permethrin. The chronic exposure at lower pesticide concentrations did not result in increased mortality or impaired growth. However, we found a positive effect of permethrin on growth and size at metamorphosis. The results suggest that the examined pesticides can inflict strong negative effects at high concentrations but have no or relatively weak effects on R. temporaria spawn or tadpoles at concentrations found in Swedish surface waters.
|
|
| 6. |
- Wiberg, Karin, et al.
(författare)
-
The fate of chiral organochlorine compounds and selected metabolites in intraperitoneally exposed arctic char (Salvelinus alpinus).
- 2006
-
Ingår i: Environmental Toxicology & Chemistry. - 0730-7268 .- 1552-8618. ; 25:6, s. 1465-73
-
Tidskriftsartikel (refereegranskat)abstract
- The fate of chiral organochlorine compounds (OCs) and selected metabolites in exposed Arctic char (Salvelinus alpinus) was investigated. The contaminants alpha-hexachlorocyclohexane (alpha-HCH), cis-chlordane, 13C4-heptachlor, o,p'-DDT, and the atropisomeric chlorinated biphenyls (CBs) 95, 132, 136, 149, and 174 were solved in peanut oil and injected into the peritoneal cavity. The exposed fish were sampled three times during a five-week period, and the OC residues and detected metabolites (heptachlorexo-epoxide) were quantified in muscle and liver tissues by chiral and achiral gas chromatography-mass spectrometry and gas chromatography-electron-capture detection. Peak concentrations were reached after one to two weeks, and thereafter, the levels declined. At the end of the experiment, liver concentrations had decreased 76 to 92% relative to peak concentrations, whereas muscle concentrations showed a moderate decline (5-38%), with the exception of alpha-HCH (91%). Hydrophobicity and steric hindrance were shown to influence the assimilation process, and a significant linear relationship between the product of the steric hindrance coefficients and the inverse of the octanol-water partition coefficients (Kow) versus peak concentration was found for the CBs (r2 = 0.86, p = 0.02). The assimilation of the contaminants into muscle and liver tissues generally resulted in racemic mixtures, whereas elimination was enantioselective for alpha-HCH, cis-chlordane, o,p'-DDT, CB-132, and CB-136. The chiral heptachlor metabolite 13C4-heptachlor-exo-epoxide was formed in the fish. The enantiomeric composition of the formed metabolite indicated racemic formation, whereas the elimination process appeared to be enantioselective.
|
|
| 7. |
- Öberg, Tomas, 1956-
(författare)
-
Virtual screening for environmental pollutants : structure-activity relationships applied to a database of industrial chemicals
- 2006
-
Ingår i: Environmental Toxicology and Chemistry. - 0730-7268 .- 1552-8618. ; 25:4, s. 1178-1183
-
Tidskriftsartikel (refereegranskat)abstract
- The current risk paradigm calls for individual consideration and evaluation of each separate environmental pollutant, but this does not reflect accurately the cumulative impact of anthropogenic chemicals. In the present study, previously validated structure-activity relationships were used to estimate simultaneously the baseline toxicity and atmospheric persistence of approximately 50,000 compounds. The results from this virtual screening indicate fairly stable statistical distributions among small anthropogenic compounds. The baseline toxicity was not changed much by halogen substitution, but a distinct increase seemed to occur in the environmental persistence with increased halogenation. The ratio of the atmospheric half-lives to the median lethal concentrations provides a continuous scale with which to rank and summarize the incremental environmental impacts in a mixture-exposure situation. Halogenated compounds as a group obtained a high ranking in this data set, with well-known pollutants at the very top: DDT metabolites and derivatives, polychlorinated biphenyls, diphenyl ethers and dibenzofurans, chlorinated paraffins, chlorinated benzenes and derivatives, hydrochlorofluorocarbons, and dichlorononylphenol. Environmentally friendly chemicals that obtained the lowest rank are nearly all hydroxylated and water-soluble. Virtual screening can assist with "green chemistry" in designing safe and degradable products and enable assessment of the efficiency in chemicals risk management.
|
|
| 8. |
- Andersson, Patrik, et al.
(författare)
-
Chemical characterization of brominated flame retardants and identification
- 2006
-
Ingår i: Environmental Toxicology and Chemistry. - 0730-7268. ; 25:5, s. 1275-82
-
Tidskriftsartikel (refereegranskat)abstract
- Three training sets were selected, each consisting of 10 structurally diverse compounds representative of brominated flame retardants (BFRs) that are either in use or have been used. Just three compounds account for nearly all the total production volume of BFRs. In the present study, however, the physicochemical characteristics of a far more structurally diverse set of 65 BFRs was explored using 15 molecular descriptors (including log P, constitutional counts, and semiempirical quantum mechanical parameters) and principal component analysis (PCA). The PCA generated an overview of the structural variation among BFRs, and certain compounds with unique physicochemical properties and specific clusters of compounds with distinct properties were identified. The training-set compounds were selected by applying the condensed information obtained from the PCA and statistical experimental design. The three training sets, which were designated as optimal, practical, and alternative, were selected either to maximize the structural variation (optimal) or to combine structural variation with practical advantages, such as ease of experimental handling and commercial availability (practical and alternative). Inclusion of the suggested compounds in assessments of the persistence, bioaccumulation, and toxicity properties of BFRs and related programs should help to increase our understanding of the effects and environmental fate of these compounds.
|
|
| 9. |
- Granberg, Maria E., 1971, et al.
(författare)
-
Role of sediment organic matter quality and feeding history in dietary absorption and accumulation of pyrene in the mud snail (Hydrobia ulvae)
- 2006
-
Ingår i: Environmental Toxicology and Chemistry. - 0730-7268. ; 25:4, s. 995-1006
-
Tidskriftsartikel (refereegranskat)abstract
- Organic matter (OM) input to marine sediments varies seasonally both in quantity and quality. Because sedimentary OM (SOM) constitutes food for many benthic organisms, its properties should affect the dietary uptake of sediment-associated contaminants. We explored the effect of SOM quality/food value on short- and long-term pyrene accumulation in the mud snail (Hydrobia ulvae) and performed dual-tracer pulse-chase experiments to investigate the feeding mechanisms driving dietary pyrene uptake. The quality of the SOM was manipulated by enriching sediments either with high-quality microalgae or low-quality lignin, adding equal amounts of total organic carbon. Long- and short-term bioaccumulation increased with increasing SOM quality, as did pyrene ingestion rate (IRPYR) which also was affected by feeding history. By feeding selectively, snails concentrated pyrene 10-fold in ingested compared to ambient sediment, independent of SOM quality. Average pyrene absorption efficiency (AE(pyr): similar to 65%) varied inversely with SOM quality and IRPYR,. Both AE(pyr), and gut passage time (alpha I/lRpyr) agreed with theoretical models incorporating the time-dependence of absorption efficiency. Thus, SOM quality moderates dietary contaminant uptake in deposit feeders, and in H. ulvae, this occurs via OM-induced alterations of ingestion rate. Consequently, enhanced sediment-associated contaminant uptake is predicted for deposit feeders following phytoplankton blooms, principally because of OM quality-driven increases in the ingestion rate.
|
|
| 10. |
- Hansson, Maria, et al.
(författare)
-
Polychlorinated biphenyl load, aryl hydrocarbon receptor, and cytochrome P4501A1 induction in a wild population of Atlantic salmon (Salmo salar) from the Baltic Sea
- 2006
-
Ingår i: Environmental Toxicology and Chemistry. - 0730-7268. ; 25:8, s. 2197-2207
-
Tidskriftsartikel (refereegranskat)abstract
- The toxicity induced by several environmental pollutants is mediated by the aryl hydrocarbon receptor (AHR), which controls the expression of many biotransformation genes, such as cytochrome P4501A1 (CYP1A1). Previous studies have indicated that fish populations can evolve tolerance to persistent chlorinated pollutants by down-regulating the AHR pathway. Here, we measure to what extent tissue loads of polychlorinated biphenyl (PCB) congeners and AHR genotypes contribute to biotransformation capacity in wild, foraging Atlantic salmon (Salmo salar L.) from the Baltic Sea. In muscle, the sum of the 21 most common PCB congeners (ΣPCB) was correlated with three extracted AHR agonists (PCBs 77/110, 118/123/149, and 105/132/153). Both the AHR agonists as well as ΣPCB were correlated with lipid content. The ΣPCB, controlled for the effects of sex and lipid content in muscle tissue, did not predict mRNA transcript levels of the measured AHRs (AHR2α, AHR2γ, and AHR2δ) or CYP1A1 in liver. However, all AHR2 mRNA transcript levels were positively correlated with CYP1A1 level. In turn, the CYP1A1 level was negatively correlated with concentration of the muscle-tissue antioxidant astaxanthin, suggesting that astaxanthin is depleted when biotransformation processes (CYP1A1) are activated. No correlation was found between ethoxyresorufin-O-deethylase activity and ΣPCB, CYP1A1, or antioxidant levels. In 5′-flanking regions of the AHR2 genes, we identified multiple allelic variants that were used for genotyping. The mRNA transcript level of AHR2α was significantly associated with the AHR2α 5′-flanking region genotype and with the interaction of the genotype and individual PCB level. These results suggest that in wild Atlantic salmon from the Baltic Sea, active production of AHR2 mRNA by means of PCB exposure may be affected by genetic polymorphisms at the AHR2 loci.
|
|
