| 1. |
- Woin, Per, 1958-, et al.
(författare)
-
Effects of metsulfuron methyl and cypermethrin exposure on freshwater model ecosystems
- 2003
-
Ingår i: Aquatic Toxicology. - Amsterdam : Elsevier. - 0166-445X .- 1879-1514. ; 63:3, s. 243-256
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate the short-term (2 weeks) effects of the herbicide metsulfuron methyl alone and in combination with the insecticide cypermethrin in freshwater enclosures (80 l). We used a factorial design with four levels of herbicide (0, 1, 5, 20 mg/l) and two levels of insecticide (0 and 0.05 mg/l). The root growth of the macrophyte species Elodea canadensis and Myriophyllum spicatum decreased following exposure to the lowest concentration of metsulfuron methyl tested. Metsulfuron methyl exposure resulted in a decreased pH in the aquatic enclosure at the lowest concentration tested, which is most likely a further indication of decreased macrophyte primary production. The biomass of periphytic algae growing on the leaves of M. spicatum increased in the enclosures exposed to metsulfuron methyl. The species composition of the periphytic algae differed significantly from the controls in the enclosures exposed to 20 mg/l of the herbicide. The increased biomass of periphytic algae on the leaves of the macrophytes is probably an indirect effect of the herbicide exposure. The exposure to metsulfuron methyl possibly induced a leakage of nutrients from the macrophyte leaves, which promoted an increased algal growth. The exposure to metsulfuron methyl did not alter the biomass or the species composition of the phytoplankton community. The zooplankton communities in the enclosures were dominated by rotifers, which were not affected by the exposure to cypermethrin. However, a cypermethrin exposure of 0.05 mg/l initially decreased the abundance of copepod nauplii. Ten days after exposure, the abundance of nauplii was significantly higher in the insecticide-exposed enclosures compared with the non-exposed enclosures. This might be an indication of a sub-lethal stress response, which either increased the number of offspring produced or induced an increased hatching of copepod resting stages. No combined effects of the herbicide and insecticide exposure, either direct or indirect, were observed in the enclosure study. Significant effects on the macrophytes were observed following exposure to 1 mg metsulfuron methyl per litre in the enclosure study. Furthermore, a single species laboratory assay indicated that the shoot elongation of E. canadensis decreased following exposure to ]/0.1 mg metsulfuron methyl per litre. These concentrations are well within the range of expected environmental concentrations, thus this study shows that aquatic ecosystems, in particular those which are macrophyte- dominated, may be affected by metsulfuron methyl at concentrations that may well occur in water bodies adjacent to agricultural land.
|
|
| 2. |
- Woin, Per, 1958-, et al.
(författare)
-
Effects of the pyrethroid insecticide cypermethrin on a freshwater community studied under field conditions : II. Direct and indirect effects on the species composition
- 2003
-
Ingår i: Aquatic Toxicology. - Amsterdam : Elsevier. - 0166-445X .- 1879-1514. ; 63:4, s. 373-389
-
Tidskriftsartikel (refereegranskat)abstract
- The effects of cypermethrin, a commonly used pyrethroid insecticide, were studied in small in situ enclosures situatedin an eutrophic lake over an 11-day period. The experimental design used a regression principle that included threeuntreated controls and a gradient of six unreplicated cypermethrin concentrations, ranging from 0.01 to 6 mg/l. Thispaper is the second in a series of two and describes the effects on the species composition of the crustacean, rotifer,periphyton and phytoplankton communities. Multivariate ordination technique (redundancy analysis (RDA) combinedwith Monte Carlo permutation tests) showed that exposure to cypermethrin caused significant changes in the speciescomposition of the communities. Changes in the structure of the communities were observed following exposure to anominal concentration of 0.13 mg cypermethrin per litre above. The direct acute effect of exposure to cypermethrin wasa rapid decrease of many species of crustacean zooplankton. The alterations in crustacean species composition wereprobably due to variations in susceptibility to the direct toxic effects of cypermethrin. No effects concentration (NEC)for individual zooplankton species were calculated using inverse regression and revealed that copepod nauplii were themost sensitive (NEC /0.01 mg/l) of the crustacean groups examined. The observed alterations of the speciescomposition of the autotrophic communities as well as of the rotifers were most likely caused indirectly bycypermethrin, mediated through the direct negative effects of the insecticide on the crustacean grazers. The results ofthis experiment provide further knowledge about the direct and indirect effects of pesticide stress on the ecosystem level.They also show that there is a variation in sensitivity between different species of zooplankton under natural conditionsand thus exemplify the necessity of multispecies approaches in the risk assessment of pesticides.
|
|
| 3. |
- Woin, Per, 1958-, et al.
(författare)
-
Effects of the pyrethroid insecticide, cypermethrin, on a freshwater community studied under field conditions : I. Direct and indirect effects on abundance measures of organisms at different trophic levels.
- 2003
-
Ingår i: Aquatic Toxicology. - Amsterdam : Elsevier. - 0166-445X .- 1879-1514. ; 63:4, s. 357-371
-
Tidskriftsartikel (refereegranskat)abstract
- The effects of the pyrethroid insecticide cypermethrin on a natural freshwater community were studied in small in situenclosures over an 11-day period. The experiment was conducted in a eutrophic lake using a regression design thatincluded three untreated controls and a gradient of six unreplicated cypermethrin concentrations, ranging from 0.01 to6.1 mg/l. This paper is the first in a series of two, and describes the fate of cypermethrin and its effects on the abundanceof crustaceans, rotifers, protozoans (cilliates and heterotrophic nanoflagellates (HNF)) and bacteria and the biomass ofperiphytic and planktonic algae. The concentration of cypermethrin decreased quickly during the experiment, with ahalf-life of 48 h for the total and 25 h for the dissolved fractions of cypermethrin, respectively. Cypermethrin proved tobe acutely toxic to crustaceans in enclosures receiving nominal cypermethrin concentrations of ]/0.13 mg/l. No EffectConcentration (NEC) and median Effect Concentration (EC50) for the total crustacean community and cladoceran andcopepod subgroups ranged between 0.02 /0.07 and 0.04 /0.17 mg/l, respectively, with copepods being less sensitive thancladocerans. The abundance of rotifers, protozoans and bacteria and the chlorophyll-a concentration of planktonic andperiphytic algae was significantly related to the concentration of cypermethrin. All groups proliferated within 2 /7 daysafter the cypermethrin application in those enclosures where the abundance of crustaceans was seriously affected bycypermethrin (i.e. ]/0.13 mg/l). We hypothesise that the proliferation of rotifers, protozoans, bacteria and algae was dueto a reduced grazer control from crustaceans and thereby mediated indirectly by cypermethrin. The results of thisexperiment provide knowledge on how an entire microplankton community may respond to pyrethroids in nature, andthe indirect effects observed on the community clearly demonstrates the necessity of multispecies field experiments inecotoxicological risk assessment
|
|
| 4. |
- Bjerselius, R, et al.
(författare)
-
Male goldfish reproductive and physiology are severely affected by exogenous exposure to 17b-estradiol
- 2001
-
Ingår i: Aquatic Toxicology. - 0166-445X .- 1879-1514. ; 53:2, s. 139-152
-
Tidskriftsartikel (refereegranskat)abstract
- Mature male goldfish were exposed to different concentrations of the natural hormone 17beta-estradiol (E2). Two methods of exposure were employed, via ingestion at 0, 1, 10 and 100 microg/g food and via the water at 0, 1 and 10 microg/l. The fish were exposed for 24-28 days during the spawning period. The males were then paired with an artificially induced, spawning female and their sexual behaviour was observed during a 15 min period. The physiological status of the fish was also examined with respect to GSI, presence of milt and spawning tubercles and the blood plasma concentration of E2. Despite the relatively short exposure period, exposure to physiological levels of E2 was shown to severely affect the male goldfish reproductive behaviour and physiology. In conclusion, the results from this study and the ability to interpret the effects on this well-studied species, show that the effects of E2, and possibly other estrogenic EDCs, have severe effects at several vital levels of male goldfish reproduction. The results also suggests that the hormone E2 can act as an endocrine disrupting chemical (EDC) in the environment.PMID: 11311390 [PubMed - indexed for MEDLINE]
|
|
| 5. |
- Bjerselius, Rickard, et al.
(författare)
-
Male goldfish reproductive behaviour and physiology are severely affected by exogenous exposure to 17 beta-estradiol
- 2001
-
Ingår i: Aquatic Toxicology. - 0166-445X .- 1879-1514. ; 53:2, s. 139-152
-
Tidskriftsartikel (refereegranskat)abstract
- Mature male goldfish were exposed to different concentrations of the natural hormone 17 beta -estradiol (El). Two methods of exposure were employed, via ingestion at 0, 1, 10 and 100 ug/g food and via the water at 0, 1 and 10 mug/l. The fish were exposed fur 74-28 days during the spawning period. The males were then paired with an artificially induced, spawning female and their sexual behaviour was observed during a 15 min period. The physiological status of the fish was also examined with respect to GSI. presence of milt and spawning tubercles and the blood plasma concentration of E-2. Despite the relatively short exposure period. exposure to physiological levels of E-2 was shown to severely affect the male goldfish reproductive behaviour and physiology. In conclusion, the results from this study and the ability to interpret the effects on this well-studied species, show that the effects of E-2, and possibly other estrogenic EDCs have severe effects at several vital levels of male goldfish reproduction. The results also suggests that the hormone E-2 can act as an endocrine disrupting chemical (EDC) in the environment.
|
|
| 6. |
|
|
| 7. |
- Engwall, Magnus, 1965-, et al.
(författare)
-
Cytochrome P450IA induction by a coplanar PCB, a PAH mixture, and PCB-contaminated sediment extracts following microinjection of rainbow trout sac-fry
- 1994
-
Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 30:4, s. 311-324
-
Tidskriftsartikel (refereegranskat)abstract
- The 7-ethoxyresorufin-O-deethylase (EROD)-inducing potencies of a coplanar polychlorinated biphenyl (PCB) (3,3',4,3',5-pentachlorobiphenyl, IUPAC No. 126), a mixture of five polycyclic aromatic hydrocarbons (benzo(k)fluoranthene, benz(a)anthracene, benzo(a)pyrene, indeno(1,2,3-cd)pyrene and chrysene), and lipophilic compounds extracted from the sediments in a PCB-contaminated lake and from sediments in lakes up- and downstream, were studied in rainbow trout sac-fry in a 43-day study. The compounds/extracts were injected into the yolk sacs of newly hatched sac-fry and hepatic EROD activities and mortality rates were measured at various times after the injections. Five livers from each group were also examined by transmission electron microscopy. All the compounds/extracts induced hepatic EROD activities in the sac-fry. Ten days after injection the EROD activity caused by PCB No. 126 (1.3 ng per embryo) was 40-fold compared to the control activity. This was the highest induction rate observed in the experiment. For the sediment extracts, the highest induction rates were observed at the first sampling occasion, which for these groups was on day 24. The extract from the Lake Jarnsjon sediment was more potent as an EROD inducer than the extracts of sediments from the lakes up- and downstream from Lake Jarnsjon. None of the sediment extracts caused any significant mortality. In sac-fry injected with the PAH mixture, EROD was only slightly induced. The highest dose of PAHs (10 mu g per embryo) caused about 90% mortality by 24 days after injection. When the livers were examined by transmission electron microscopy, morphological alterations (e.g. hepatocyte degeneration and hypertrophy) were seen in the groups injected with Lake Jarnsjon sediment extract, PCB No. 126 and the highest dose of the PAH mixture (10 mu g per embryo).
|
|
| 8. |
|
|
| 9. |
- Larsson, D. G. Joakim, 1969, et al.
(författare)
-
Ethinyloestradiol – an undesired fish contraceptive?
- 1999
-
Ingår i: Aquatic Toxicology. - 0166-445X .- 1879-1514. ; 45:2-3, s. 91-97
-
Tidskriftsartikel (refereegranskat)abstract
- Environmental oestrogens are natural or synthetic substances present in the environment, which imitate the effects of endogenous oestrogen. Oestrogenic substances were identified by gas chromatography/mass spectrometry in effluent water from a Swedish sewage treatment works receiving mainly domestic wastewater. Substances found include the synthetic oestrogen used in contraceptives 17 alpha-ethinyloestradiol (4.5 ng l(-1)), the natural oestrogens oestrone (5.8 ng l(-1)) and 17 beta-oestradiol (1.1 ng l(-1)), and the weaker non-steroidal oestrogens 4-nonylphenol (840 ng l(-1)) and bisphenol A (490 ng l(-1)). Ethinyloestradiol exceeded levels shown to be oestrogenic to fish by 45 times. The oestrogenicity of the effluent water was investigated by introducing juvenile rainbow trout (Oncorhynchus mykiss) in cages downstream of the sewage treatment works. After 2 weeks, all oestrogens indicated were present in the bile of the fish, and the oestrogen inducible protein, vitellogenin, was found in large amounts in the plasma (1.5 mg ml(-1)), as determined by enzyme-linked immunosorbent assay and Western blotting. Thus, a widely used synthetic oestrogen affects the endocrine systems of fish exposed to sewage effluent water.
|
|
| 10. |
- Skarpheoinsdottir, H, et al.
(författare)
-
Tissue differences, dose-response relationship and persistence of DNA adducts in blue mussels (Mytilus edulis L.) exposed to benzo[a]pyrene
- 2003
-
Ingår i: Aquatic Toxicology. - 0166-445X .- 1879-1514. ; 62:2, s. 165-177
-
Tidskriftsartikel (refereegranskat)abstract
- Baltic Sea blue mussels Mytilus edulis) were experimentally exposed to the genotoxic model substance benzo[a]pyrene (B[a]P) to study DNA adduct formation. The specific aims were (a) to examine where in the mussels the DNA adducts were formed, in gills or digestive glands (b) to study the dose-response relationship between B[a]P exposure and DNA adduct formations and (c) to examine the persistence of the formed adducts. A Scope for growth (SFG) study was also run to compare physiological responses of the mussels with the degree of DNA adduct formation. In an initial dose-response experiment, the mussels were exposed to 0.5, 50, and 100 mug/l of tritium labelled B[a]P under semi-static conditions for 4 days, and thereafter the bioaccumulation of B[a]P and DNA adduct formation in different tissues was determined using liquid scintillation counting and P-32-postlabelling analysis. respectively. In a following exposure-depuration experiment, mussels were exposed to 17 mug/l of radiolabelled B[a]P under semi-static conditions for 6 days. B[a]P accumulation and DNA adduct formation were determined during the exposure, and B[a]P elimination and persistence of DNA adducts were studied during 28 days of depuration in uncontaminated water, The results revealed large tissue differences in DNA adduct formation. DNA adduct levels were not elevated in the digestive gland of the mussels at any exposure concentration (0-100 mug/l). even though the highest B[a]P tissue concentrations were found in the digestive gland (1.0+/-0.1 mg B[a]P/g tissue dry wt at 100 mug/l, mean+/-SE. n = 12). DNA adducts were on the other hand formed in the gills, with the highest levels found in mussels exposed to 50 and 100 mug B[a]P/l. and a dose dependent increase in adduct levels (from 1.6 to 5.9 nmol adducts/mol nucleotides) from 0 to 50 mug B[a]P/l, In gills, DNA adduct levels increased with time during the 6-day exposure period in the exposure-depuration experiment, and then persisted for at least 2 weeks after exposure cessation while B[a]P tissue levels exhibited a rapid decrease (half-life of 8 days). No significant differences were observed in SFG between the control and exposed groups. Since DNA adducts exhibited a relatively high persistence in gills compared to B[a]P tissue concentrations, they seem to be a more integrated measure of genotoxic exposure than only chemical analysis of the contaminant bioaccumulation. The results also suggest that if using analysis of DNA adducts in H. edulis for monitoring purposes. analysis of gills in addition to the more commonly used digestive gland should be taken into consideration.
|
|
