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By measuring a battery of cytological and biochemical biomarkers in adult female perch (Perca fluviatilis), the city of Stockholm (Sweden) was investigated as a point source of anthropogenic aquatic pollution. The investigation included both an upstream gradient, 46 km westwards through Lake Mälaren, and a downstream gradient, 84 km eastwards through the Stockholm archipelago. Indeed, there was a graded response for most of the biomarkers and for the muscle concentrations of ΣPBDE, four organotin compounds and PFOS in the perch. The results indicated severe pollution in central Stockholm, with poor health of the perch, characterised by increased frequency of micronucleated erythrocytes, altered liver apoptosis, increased liver catalase activity, decreased brain aromatase activity, and decreased liver lysosomal membrane stability. Some biomarker responses were lowest in the middle archipelago and increased again eastwards, indicating a second, partly overlapping, gradient of toxic effects from the Baltic Sea., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Modern chemical legislation requires measuring the bioconcentration factor (BCF) of large numbers of chemicals in fish. The BCF must be corrected for growth dilution, because fish growth rates vary between laboratories. Two hypotheses were tested: (1) that BCFs of multiple chemicals can be measured simultaneously in one experiment, and (2) that internal benchmarking using a conservative test substance in the chemical mixture can be used to correct for growth dilution. Bioconcentration experiments were conducted following major elements of the OECD 305 guideline. Fish were simultaneously exposed to 11 chemicals selected to cover a range of BCFs and susceptibility to biotransformation. A method was developed to calculate the growth-corrected elimination rate constant from the concentration ratio of the analyte and a benchmarking chemical for which growth dilution dominated other elimination mechanisms. This method was applied to the experimental data using hexachlorobenzene as the benchmarking chemical. The growth dilution correction lowered the apparent elimination rate constants by between 5% and a factor of four for eight chemicals, while for two chemicals the growth-corrected elimination rate constant was not significantly different from zero. The benchmarking method reduced the uncertainty in the elimination rate constant compared to the existing method for growth dilution correction. The BCFs from exposing fish to 10 chemicals at once were consistent with BCF values from single-chemical exposures from the literature, supporting hypothesis 1., (Copyright © 2012 SETAC.)

The application of in-tissue passive sampling to quantify chemical kinetics in fish bioconcentration experiments was investigated. A passive sampler consisting of an acupuncture needle covered with a PDMS tube was developed together with a method for its deployment in rainbow trout. The time to steady state for chemical uptake into the passive sampler was >1d, so it was employed as a kinetically limited sampler with a deployment time of 2 h. The passive sampler was employed in parallel with the established whole tissue extraction method to study the elimination kinetics of 10 diverse chemicals in rainbow trout. 4-n-nonylphenol and 2,4,6-tri-tert-butylphenol were close to or below the limit of quantification in the sampler. For chlorpyrifos, musk xylene, hexachlorobenzene, 2,5-dichlorobiphenyl and p,p'-DDT, the elimination rate constants determined with the passive sampler method and the established method agreed within 18%. Poorer agreement (35%) was observed for 2,3,4-trichloroanisole and p-diisopropylbenzene because fewer data were obtained with the passive sampling method due to its lower sensitivity. The work shows that in-tissue passive sampling can be employed to measure contaminant elimination kinetics in fish. This opens up the possibility of studying contaminant kinetics in individual fish, thereby reducing the fish requirements and analytical costs for the determination of bioconcentration factors., (Copyright © 2012 Elsevier Ltd. All rights reserved.)