Trophic transfer of pyrene metabolites and nonextractable fraction from Oligochaete (Lumbriculus variegatus) to juvenile brown trout (Salmo trutta)

Cell lines of Etroplus suratensis established in our laboratory were evaluated for their potential use as screening tools for the ecotoxicological assessment of tannery effluent. The cytotoxic effect of tannery effluent in three cell lines derived from eye, kidney and gill tissue of E. suratensis was assessed using multiple endpoints such as Neutral Red (NR) assay, Coomassie Blue (CB) protein assay and Alamar Blue (AB) assay. Acute toxicity tests on fish were conducted by exposing E. suratensis for 96 h to tannery effluent under static conditions. The toxic effect of tannery effluent on the survival of fish was found to be concentration and time dependent. The tannery effluent at the concentration of 15% caused 100% mortality at 96 h whereas the lower concentration (0.5%) caused 13.33% mortality. The cytotoxicity of tannery effluent was found to be similar in the three cell lines tested, independent of the toxic endpoints employed. EC₅₀ values, the effective concentration of tannery effluent resulting in 50% inhibition of cytotoxicity parameters after 48 h exposure to tannery effluent were calculated for eye, kidney and gill cell lines using NR uptake, AB and cell protein assays. Statistical analysis revealed good correlation with r² = 0.95-0.99 for all combinations between endpoints employed. Linear correlations between each in vitro EC₅₀ and the in vivo LC₅₀ data, were highly significant p < 0.001 with r² = 0.977, 0.968 and 0.906 for AB₅₀, NR₅₀, and CB₅₀, respectively.     

Bioaccumulation of paraquat by Lumbriculus variegatus in the presence of dissolved natural organic matter and impact on energy costs, biotransformation and antioxidative enzymes

Dissolved organic matter from natural sources (DNOM) is omnipresent in aquatic ecosystems. Besides affecting bioavailability of substances including xenobiotics, it directly influences physico-chemistry of the habitat and there is increasing evidence for it is interaction with organisms. We investigated direct and interacting effects of DNOM from three sources, Lake Valkea-Kotinen, Svartberget Brook, and Lake Fuchskuhle with the herbicide paraquat on the oligochaete worm Lumbriculus variegatus. Bioavailability of paraquat to L. variegates as well as activities of antioxidative enzymes catalase (CAT) and peroxidase (POD) and biotransformation enzyme soluble glutathione S-transferase (sGST) were assessed without and in the presence of DNOM. Furthermore, metabolic heat dissipation due to the exposure was quantified. Uptake of paraquat into the worms was concentration dependently reduced by DNOM, and with differences concerning the DNOM sources. sGST and CAT responded with increased activities to DNOM (5 and 25 mg C l-1) and paraquat (5.0, 50, and 500 microg l-1) separately. Paraquat at 5.0 microg l-1 and DNOM in combination caused increased activities of sGST, especially at 5 mgC l-1, but inhibition of CAT activities. The latter probably occurred due to saturation of the enzyme. Changes in enzyme activities were independent from the source of DNOM. Increasing DNOM concentrations raised metabolic heat dissipation in L. variegatus with maximum at 3h of exposure. In the combined treatments, metabolic heat dissipation changed more due to the source of DNOM than due to the bioavailability of paraquat.     

Environmental toxins in Finnish Wildlife. A study on time trends of residue contents in fish during 1973–1978

The O.E.C.D. monitoring Wildlife Sampling and Analysis Programme 1973–1975 has been extended at national level in Finland to 1978 by analysing chlorinated hydrocarbon residues in fish at two marine and two freshwater environments and mercury at the latter two freshwater environments. Statistical treatment of the analysis results gave significant decreasing trends in most cases of PCB and DDT residues but in mercury levels no significant change was detected.     

Postmetamorphic Xenopus laevis shows decreased plasma triiodothyronine concentrations and phosphorylase activity due to subacute phytosterol exposure

Postmetamorphic South African clawed frogs (Xenopus laevis) were exposed to a phytosterol mixture (ca. 80% β-sitosterol and less sitostanol, campesterol, and campestanol) for 14 days at 30 μg l⁻¹ in a flow-through system. The effects of phytosterols (PS) on the plasma thyroid hormone (T₃ and T₄), testosterone, leptin-immunoreactive peptide and tissue glycogen concentrations were determined. The following enzyme activities were also analyzed from the liver and muscle: glycogen phosphorylase and lipase, and from the liver only: glucose-6-phosphatase. The plasma T₃ concentration was lower in the PS-exposed female frogs. Both muscle lipase and glycogen phosphorylase activities were also lower in the PS-exposed animals. These results could indicate that the basal metabolic rate and locomotion activity of the frogs were decreased. The effects could not be attributed to the possible estrogenicity of the PS mixture. Further studies will be needed to evaluate the possible significance of these effects.     

Bisphenol A induces yolk-sac oedema and other adverse effects in landlocked salmon (Salmo salar m. sebago) yolk-sac fry

Accumulation and toxicity of waterborne bisphenol A were studied in landlocked salmon (Salmo salar m. sebago) yolk-sac fry. In a short-term (96 h) exposure to five bisphenol A concentrations yolk-sac fry had higher accumulation rates and bioconcentration factors (BCF96) than earlier studies have shown for salmon eggs. Furthermore, the conditional uptake rate constant tended to decrease as exposure concentration increased. Fry were also exposed to bisphenol A for 42 days at three concentrations (10, 100 and 1000 microg/l), and changes in behaviour, morphology and histological structure were observed. After 6 days of exposure, the highest concentration (1000 microg/l) of bisphenol A caused fluid accumulation (oedema) in the yolk sac and haemorrhages in the front part of the yolk sac and in the head around the gill arches. Later on, the fry at 1000 microg/l showed phlegmatic behaviour and had darker skin coloration than the fry in the other treatments. At the two highest concentrations (100 and 1000 microg/l) histological changes were seen in liver cell nuclei, where strongly stained fragments were observed. In the control fry and the fry exposed to 10 microg/l the nucleolus was clearly visible and spherical in shape and no strongly stained fragments were present. This study shows that high concentrations of bisphenol A may have both morphological and histological effects on salmon yolk-sac fry.     

Screening of halogenated aromatic compounds in some raw material lots for an aluminium recycling plant

Four samples of scrap raw materials for an aluminium recycling plant were screened for the occurrence of persistent halogenated aromatic compounds. The samples contained waste from handling of electric and electronic plastics, filter dust from electronic crusher, cyclone dust from electronic crusher and light fluff from car shredder. In our screening analyses, brominated flame retardants were observed in all samples. Polybrominated diphenyl ethers (PBDE) were identified in all samples in amounts of 245-67450 ng/g. The major PBDE congeners found were decabromo- and pentabromodiphenyl ethers. 1,1-bis(2,4,6-tribromophenoxy)ethane, hexabromobenzene, ethyl-pentabromobenzene, tetrabromobisphenol-A, pentabromotoluene and dimethyl tetrabromobenzene were observed in all scrap samples. The concentrations of PCBs, PCNs (polychlorinated naphthalenes) and nona- to undecachlorinated terphenyls in some of these scrap samples were remarkably high.     

Trends of organochlorine compounds in Finnish inland waters

Caged common lake mussels (Anodonta piscinalis) have been used in the monitoring of organochlorine compounds in pulp and paper mill recipient watercourses of Finland annually from 1984 to 1998. Statistically significant decreasing trends of chlorophenols and chloroguaiacols originating from chlorobleaching were observed in all recipients in parallel with the decreasing discharges from the mills. Metabolites of chlorophenols, chloroanisoles and chloroveratroles had no or slightly increasing trends. Elevated PCB concentrations were measured in four watercourses. In two areas, PCBs were found to be significantly increasing, in two other cases they showed no trend. A mill producing recycled paper was apparently responsible for an increase of PCBs and DDE in recipient watercourses. Overall decreases were observed for other chlorohydrocarbons except for DDT. Material flows of chlorohydrocarbons were positively correlated with waterflows (Q) in some cases.     

The effects of solar UV-B radiation on embryonic mortality and development in three boreal anurans (Rana temporaria, Rana arvalis and Bufo bufo).

Many species of amphibians have experienced population and range reductions. It has been hypothesized that sensitivity to UV-B may contribute to the population declines of some amphibian species. We performed field experiments to measure the effects of solar UV-B on the hatching success of three Finnish anuran species, the common frog (Rana temporaria), moor frog (Rana arvalis) and common toad (Bufo bufo). Further, the effects of natural UV-B radiation on survival of the tadpoles of the same three species of anurans were tested. A significant percentage of R. temporaria and B. bufo embryos survived when exposed to and protected from solar UV-B and hatching success was not affected by solar radiation. Elimination of solar UV-B significantly increased the hatching success of R. arvalis, but embryonic mortality was high in both treatments. The data indicates that under natural conditions, solar UV-B radiation influences embryo survival in R. arvalis, but has no effect on R. temporaria and B. bufo. Solar UV-B radiation had no effect on R. temporaria and R. arvalis tadpoles, but elimination of UV-B significantly increased survival of B. bufo tadpoles. It seems that ambient UV-radiation levels have no effect on R. temporaria but may affect R. arvalis and B. bufo at different developmental stages.     

Optimisation of chemical purification conditions for direct application of solid metal salt coagulants: Treatment of peatland-derived diffuse runoff

The drainage of peatland areas for peat extraction,agriculture or bioenergy requires affordable,simple and reliable treatment methods that can purify waters rich in particulates and dissolved organic carbon.This work focused on the optimisation of chemical purification process for the direct dosage of solid metal salt coagulants.It investigated process requirements of solid coagulants and the influence of water quality,temperature and process parameters on their performance.This is the first attempt to provide information on specific process requirements of solid coagulants.Three solid inorganic coagulants were evaluated:aluminium sulphate,ferric sulphate and ferric aluminium sulphate.Pre-dissolved aluminium and ferric sulphate were also tested with the objective of identifying the effects of in-line coagulant dissolution on purification performance.It was determined that the pre-dissolution of the coagulants had a significant effect on coagulant performance and process requirements.Highest purification levels achieved by solid coagulants,even at 30% higher dosages,were generally lower(5%-30%) than those achieved by pre-dissolved coagulants.Furthermore,the mixing requirements of coagulants pre-dissolved prior to addition differed substantially from those of solid coagulants.The pH of the water samples being purified had a major influence on coagulant dosage and purification efficiency.Ferric sulphate(70 mg/L) was found to be the best performing solid coagulant achieving the following load removals:suspended solids(59%-88%),total organic carbon(56%-62%),total phosphorus(87%-90%),phosphate phosphorus(85%-92%) and total nitrogen(33%-44%).The results show that the use of solid coagulants is a viable option for the treatment of peatland-derived runoff water if solid coagulant-specific process requirements,such as mixing and settling time,are considered.