Search

A paper-based colourimetric assay for the Point-of-Care Testing (PoCT) of bilirubin has been developed based on the formation of a green-coloured copper-bilirubin complex from a blue-coloured tetraamminecopper(II) sulphate complex. The reaction was studied and optimized by UV-Visible absorption spectroscopy and translated onto a paper strip. Hydrophobic circular well patterns on Whatman chromatography paper were created by wax printing. The tetraamminecopper(II) sulphate complex was drop cast and dried on the reagent zones in the wax-patterned paper. The images of reagent zones captured using a scanner were analyzed using ImageJ software. Bilirubin spiked blood serum was tested in the concentration range of 1.2 to 950 µM. The PAD exhibited sensitivities of 0.4197 a.u/μM and 0.1040 a.u/μM for concentration ranges of bilirubin 1.2 to 96 μM and 105 to 950 μM respectively and a low detection limit of 0.799 µM. The method is highly selective to bilirubin, even in the presence of other biomarkers in serum. A plasma separation membrane incorporated PAD was fabricated for the final testing and quantification of bilirubin from whole blood.

The treatment of pulp and paper mill wastewater by combining an ultrafiltration (UF) membrane and advanced oxidation processes (AOPs) was investigated at a bench scale. In the present study, the effects of impressive parameters on membrane fouling such as CaCl2 (mg/L), pH, and temperature (°C) were studied using response surface methodology (RSM). According to the results yielded, at the temperature of 45°C, pH of 10 and CaCl2 concentration of 400 mg/L, the fouling reached its minimum (32%). Therefore, scanning electron microscopy (SEM) analyses showed that the average thickness of cake layer on the UF surface decreased from approximately 75.37 µm to 11.38 µm by optimizing the operating conditions. The results showed the UF permeate quality is not sufficient. Thus, AOPs applied for permeate. In this way, the performance of sulfate and hydroxyl radicals, generated by the activation of oxidants, such as persulfate () and H2O2, by Fe(II) for removal efficiencies was examined. Accordingly, under the o...

We studied the avoidance behaviour of the earthworm Eisenia fetida towards Cd, Cu, and Zn, trace elements (TEs) tested as chloride, nitrate and sulphate salts. Sub adults were exposed individually using dual-cell chambers at 20+2°C in the dark. Recordings were realised at different dates from 2h to 32h. We used filter paper and extruded water agar gel as exposure media to evaluate the contribution of the dermal and the digestive exposure routes on the avoidance reactions. Exposures to Cu or Cd (10mgmetal ionL(-1)) resulted in highly significant avoidance reactions through the exposure duration. Worms avoided Zn poorly and reactions towards Zn salts varied along the exposure. Worm sensitivity towards TEs differed between salts and this could result from differential toxicity or accessibility of these TE salts to earthworms. The anion in itself was not the determinant of the avoidance reactions since exposures to similar concentrations of these anions using calcium salts did not result in significant avoidance worm behaviour. Avoidance responses towards TEs were higher in the case of water agar exposures than in filter paper exposures. Thus, dermal contacts with TE solutions would elicit worm avoidance but signals from receptors located inside the digestive tract could reinforce this behaviour. The use of extruded water agar gels as the substrate allows checking the real sensitivity of earthworm species towards TEs since the TE concentrations leading to significant avoidance reactions were below those reported in the literature when using TE-spiked soils.

Mixed sludge from a pulp and paper mill was hydrothermally carbonized at 180–260 °C for 0.5–5 h with the use of HCl or NaOH for determining the effect of acid and base additions during sludge carbonization. Based on the results carbonization was mainly governed by dehydration, depolymerization and decarboxylation of sludge components. Additive type had a statistically significant effect on hydrochar carbon content and carbon and energy yield, of which especially energy yield increased through the use of HCl. The theoretical energy efficiencies of carbonization increased with decreasing reaction temperature, retention time and the use of HCl and suggested that the energy requirement could be covered by the energy content of attained hydrochar. The BOD5/COD-ratios of analyzed liquid samples indicated that the dissolved organic components could be treated by conventional biological methods.

In this work, pulp mill wastewater was treated using a novel copolymer flocculant with a high water-solubility, which was synthesized through grafting (2-methacryloyloxyethyl) trimethyl ammonium chloride (DMC) onto chitosan initiated by potassium persulphate. The experimental results demonstrate that the two main problems associated with the utilization of chitosan as a flocculant, i.e., low molecular weight and low water-solubility, were concurrently sorted out. The physicochemical properties of this flocculant were characterized with Fourier-transform infrared spectroscopy, 1H nuclear magnetic resonance spectroscopy, X-ray powder diffraction and field emission scanning electron microscopy. Reaction parameters influencing the grafting percentage, such as temperature, reaction time, initiator concentration and monomer concentration, were optimized using an orthogonal array design matrix. With an increase in grafting percentage, the water-solubility of the flocculant was improved, and it became thoroughly soluble in water when the grafting percentage reached 236.4% or higher. Its application for the treatment of pulp mill wastewater indicates that it had an excellent flocculation capacity and that its flocculation efficiency was much better than that of polyacrylamide. The optimal conditions for the flocculation treatment of pulp mill wastewater were also obtained.

The aim of this work is to study the possibilities of effluent recycling in a bleached Kraft pulp mill, for a better water management. To avoid problems associated with effluent recycling (corrosion, odors, loss in pulp and paper quality), wastewaters have to be treated before recycling. This study is particularly focused on organic matter removal. Several treatments are applied on a biological secondary effluent: adsorption on activated carbon, coagulation with ferric chloride or alum sulfate, precipitation with lime, ozonation and catalytic ozonation. These techniques are compared in terms of COD (Chemical Oxygen Demand) removal. Catalytic ozonation is finally chosen as the most effective solution to achieve 50% of COD removal in the effluent. The characteristics of the effluent treated according to this technique are then used to simulate the impact of its reuse in the process for pulp production. The study is focused on the changes in these parameters in the various stages of bleaching and final washing when water is replaced by the wastewater treated or directly issued from the wastewater treatment plant. The simulation demonstrates the need of a tertiary treatment to eliminate COD in order to avoid possible reactant overconsumption and decrease in pulp brightness. Chloride and sulfate ions which could cause corrosion should also be removed.

The efficiency of a bioelectrochemical treatment system (BET) to treat complex paper and pulp wastewater at two different pH conditions (6 and 7) in comparison with conventional anaerobic treatment process (AnT) was evaluated. Among the operating conditions, BET showed good treatment efficiency at pH 7 in terms of COD (BET/AnT: 55%/51%), nitrates (33.5%/19.1%), phosphates (33%/19%) and sulfates (58%/41%) in removal. The effluent obtained from BET system was subjected to coagulation for further treatment which showed good COD removal (BET/AnT, 95%/69%) and color (100%/68%). Bioelectrochemical analysis revealed higher catalytic currents in BET than AnT specific to oxidation and reduction. Besides, derivative of cyclic voltammetric scans (DCV) also supported the involvement of various membrane bound electron transferring complexes like FAD(H) bound enzymes, ubiquinone, NADH(+)/H(+) bound enzymes, etc. Experimental results demonstrated that BET system can be a viable platform to treat complex wastewaters with simultaneous energy recovery in integrated approach.

International audience; To better understand the degradation of cellulose upon the formation of a tideline at the wet–dry interface when paper is suspended in water, the production of chemical species involved in oxidation reactions was studied. The quantitation of hydroperoxides and hydroxyl radicals was carried out in reverse phase chromatography using triphenylphosphine and terephthalic acid, respectively, as chemical probes. Both reactive oxygen species were found in the tideline immediately after its formation, in the range of micro-moles and nanomoles per gram of paper, respectively. The results indicate that hydroxyl radicals form for the most part in paper before the tideline experiment, whereas hydroperoxides appear to be produced primarily during tideline formation. Iron sulfate impregnation of the paper raised the production of hydroperoxides. After hygrothermal aging in sealed vials the hydroxyl radical content in paper increased significantly. When aged together in the same vial, tideline samples strongly influenced the degradation of samples from other areas of the paper (multi-sample aging). Different types of antioxidants were added to the paper before the tideline experiment to investigate their effect on the oxidation reactions taking place. In samples treated with iron sulfate or artificially aged, the addition of Irgafos 168 (tris(2,4-ditert-butylphenyl) phosphate) and Tinuvin 292 (bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate) reduced the concentration of hydroperoxides and hydroxyl radicals, respectively. Tinuvin 292 was also found to considerably lower the rate of cellulose chain scission reactions during hygrothermal aging of the paper.

Associations between various malignancies and work in the pulp and paper industry have been reported but mostly in analyses of mortality rather than incidence. We aimed to study cancer incidence by main mill pulping process, department and gender in a Swedish cohort of pulp and paper mill workers. The cohort (18,113 males and 2,292 females, enrolled from 1939 to 1999 with >1 year of employment) was followed up for cancer incidence from 1958 to 2001. Information on the workers’ department and employment was obtained from the mills’ personnel files, and standardized incidence ratios (SIRs) were calculated using the Swedish population as reference. Overall cancer incidence, in total 2,488 cases, was not increased by work in any department. However, risks of pleural mesothelioma were increased among males employed in sulphate pulping (SIR, 8.38; 95 % CI, 3.37–17) and maintenance (SIR, 6.35; 95 % CI, 3.47–11), with no corresponding increase of lung cancer. Testicular cancer risks were increased among males employed in sulphate pulping (SIR, 4.14; 95 % CI, 1.99–7.61) and sulphite pulping (SIR, 2.59; 95 % CI, 0.95–5.64). Female paper production workers showed increased risk of skin tumours other than malignant melanoma (SIR, 2.92; 95 % CI, 1.18–6.02). Incidence of pleural mesothelioma was increased in the cohort, showing that asbestos exposure still has severe health consequences, and highlighting the exigency of strict asbestos regulations and elimination. Testicular cancer was increased among pulping department workers. Shift work and endocrine disruptors could be of interest in this context.

In anaerobic wastewater treatment, the occurrence of biological sulfate reduction results in the formation of unwanted hydrogen sulfide, which is odorous, corrosive and toxic. In this paper, the role and application of bacteria in anaerobic and aerobic sulfur transformations are described and exemplified for the treatment of a paper mill wastewater. The sulfate containing wastewater first passes an anaerobic UASB reactor for bulk COD removal which is accompanied by the formation of biogas and hydrogen sulfide. In an aeration pond, the residual CODorganic and the formed dissolved hydrogen sulfide are removed. The biogas, consisting of CH4 (80¿90 vol.%), CO2 (10¿20 vol.%) and H2S (0.8¿1.2 vol.%), is desulfurised prior to its combustion in a power generator thereby using a new biological process for H2S removal. This process will be described in more detail in this paper. Biomass from the anaerobic bioreactor has a compact granular structure and contains a diverse microbial community. Therefore, other anaerobic bioreactors throughout the world are inoculated with biomass from this UASB reactor. The sludge was also successfully used in investigation on sulfate reduction with carbon monoxide as the electron donor and the conversion of methanethiol. This shows the biotechnological potential of this complex reactor biomass.

Final effluent from a pulp and paper kraft mill was exposed to power ultrasound at 357 kHz with the aim of reducing color, turbidity, and chemical oxygen demand (COD). Absorbance measurements showed a bleaching of the effluent at wavelengths above 250 nm, indicating loss of aromatic chromophores. Effluent turbidity also decreased. Surprisingly, there was no observable decrease in COD, within experimental error. This is attributed to the presence of bicarbonate and sulfate ions in the final effluent, which react with hydroxyl radicals and effectively block the oxidation of organics in the effluent. This was demonstrated by sonicating solutions of potassium hydrogen phthalate (KHP) containing chloride, bicarbonate, or sulfate ions, which are the major inorganic ions in the final effluent studied. A solution containing only 2.3 mM KHP showed a 19% reduction in COD after 6 h of sonication. An identical solution with 200 ppm chloride also showed a 19% COD reduction. However, solutions with 700 ppm sulfate and 400 ppm bicarbonate showed COD reductions of 11% and 3%, respectively.

A novel sulfate-reducing bacterium, strain HB1(T), was isolated from an upflow anaerobic sludge blanket (UASB) reactor treating paper-mill wastewater operated at 37 degrees C. Cells of strain HB1(T) were oval to rod-shaped, 1-1.3 microm wide and 2.6-3.5 microm long and Gram-negative. The optimum temperature for growth was 28-30 degrees C. In the presence of sulfate, the isolate was able to grow on H(2)/acetate, formate, ethanol, propionate, fumarate, succinate, butyrate, crotonate, catechol, benzoate, 4-hydroxybenzoate, palmitate and stearate. The isolate only grew on H(2) when acetate was added as a carbon source; when grown on formate, acetate was not required. Growth was also possible on pyruvate and crotonate without an electron acceptor. The isolate showed very poor growth on acetate. Thiosulfate and sulfate were used as electron acceptors. Phylogenetic analysis of 16S rRNA gene sequences revealed that strain HB1(T) represents a novel lineage within the Deltaproteobacteria; sequence similarities between strain HB1(T) and members of other related genera were less than 91%. Strain HB1(T) was also distinguished from members of related genera based on differences in several phenotypic characteristics. It is a member of the family Desulfobacteraceae. The major cellular fatty acids of strain HB1(T) were C(16:0), iso-C(15:0), anteiso-C(15:0) and C(14:0). beta-Hydroxy fatty acids were also present in the range of C(14:0) to C(18:0), of which C(16:0) was the most abundant. The G+C content of the DNA was 55.1 mol%. Based on physiological, biochemical and chemotaxonomic traits together with results of comparative 16S rRNA gene sequence analysis, strain HB1(T) is considered to represent a novel species in a new genus, for which the name Desulfatirhabdium butyrativorans gen. nov., sp. nov. is proposed. The type strain of Desulfatirhabdium butyrativorans is HB1(T) (=DSM 18734(T) =JCM 14470(T)).

Denitrification is applied in the tertiary treatment of wastewater to reduce nitrogen pollution. Fluorescence in situ hybridization (FISH), catalyzed reporter deposition (CARD)-FISH, cloning, and scanning electron microscopy (SEM) were applied to follow the evolution of the microbial composition and structure of granular sludge in chemolithotrophic denitrifying bioreactors fed with nitrate and thiosulfate. FISH oligonucleotide probes for the chemolitoautotrophic denitrifiers Thiobacillus denitrificans and Thiomicrospira denitrificans were designed and their utility tested. CARD-FISH and cloning data showed that bacterial diversity in the biofilms changed during the reactor operation. Chemoorganotrophic fermentative Gram-positive strains in the phyla, Actinobacteria and Firmicutes, were dominant in the methanogenic inoculum, both in terms of biodiversity and in number. Other significant phyla were Bacteroidetes and Chloroflexi. After 6 months of operation, Proteobacteria became dominant (83% of the clones). The diversity of Gram-positive bacteria was partially maintained although their abundance decreased notably. After 110 d of operation, the abundance of Tb. denitrificans cells increased considerably, from 1% to 35% of total DAPI-stained cells and from no isolated clones to 15% of the total clones. Tm. denitrificans only represented a minor fraction of the microorganisms in the sludge (1-4% of the DAPI-stained cells). These findings confirm that Tb. denitrificans was the dominant chemolitoautotrophic denitrifying microorganism in the bioreactors. The Archaeal diversity remained almost unchanged and it was represented mostly by Methanosaeta soehngenii. SEM results indicated a considerable loss in the integrity of the sludge granules during the operation, with risk of sludge buoyancy.

The usefulness of microwave muffle furnaces for increasing the efficiency of sulfated ash determination through automation was investigated. Substances critical in their behavior were selected as model substances for this purpose: megestrol acetate and a phthalazine derivative as substances with high foaming indices and azelaic acid as a substance with a high spatter index. The selection of an optimal temperature sequence in conjunction with quartz crucibles and/or with a spatter guard made of quartz filter paper made it possible to handle even these critical substances. The analysis results were comparable and reproducible in terms of classical pharmacopeia methodology.

This study concerned the anaerobic treatment of five different industrial wastewaters with a diverse and complex chemical composition. The kinetics of biotransformation of this wastewater at different chemical oxygen demand (COD) were studied in a batch reactor. Wastewater from an amino acid producing industry (Fermex) and from a tank that received several types of wastewaters (collector) contained 0.83 g l(-1) and 0.085 g l(-1) sulfate, respectively. During the study period of 20 days, methane formation was observed in all types of wastewaters. Studies on COD biodegradation showed the reaction velocity was higher for Fermex wastewater and lower for collector wastewater, with values of 0.0022 h(-1) and 0.0011 h(-1), respectively. A lower methanogenic activity of 0.163 g CH4 day(-1) g(-1) volatile suspended solids (VSS) and 0.20 g CH4 day(-1) g(-1) VSS, respectively, was observed for paper producing and brewery wastewater. Adapted granular sludge showed the best biodegradation of COD during the 20-day period. The sulfate-reducing activity in pharmaceutical and collector wastewater was studied. A positive effect of sulfate-reducing activity on methanogenic activity was noted for both types of wastewaters, both of which contained sulfate ions. All reactions of methane generation for the tested industrial wastewaters were first-order. The results of this study suggest that the tested wastewaters are amenable to anaerobic treatment.

Objectives This study investigated whether previous findings of an increased risk of gliomas among workers in some pulp and paper mills could be confirmed for all Swedish pulp and paper mill workers and whether the increase could be attributed to certain occupational groups. Methods The study was based on the Swedish Cancer Environment Register, which links the incidence of cancer from 1971 to 1990 and the 1960 and 1970 census data on codes of occupation and industry for the whole population. Standardized incidence ratios (SIR) were used to estimate the risks for men in different occupations in pulp (N=28 142) and paper (N=39 169) mills in 1960, 1970 or both years as compared with those of all gainfully employed men in Sweden. Results Maintenance workers employed in pulp or paper mills in 1960, 1970 or both years, as well as pulp workers, showed an increased incidence of gliomas in 1971-1990 [SIR 1.5, 95% confidence interval (95% CI) 1.1-2.1 and SIR 1.5, 95% CI 1.0-2.2, respectively], whereas the incidence among process workers in paper mills was lower than expected (SIR 0.6, 95% CI 0.3-0.9). Taken together, all employed men in the pulp mill industry had an increased incidence of gliomas (SIR 1.3, 95% CI 1.0-1.7). Conclusions Pulp mill workers, but not paper mill workers, were found to have more gliomas in 1971-1990 than expected. There was an increased risk of gliomas among maintenance workers in both pulp and paper mills. Few risk factors for brain tumors are recognized, and the causes of the increase are not obvious.

In this paper we describe an alternative flow-chart for full treatment of wastewaters rich in organic substrates, ammonia (or organic nitrogen), and sulfate, such as those generated in fish cannery industries. Biogas generated during anaerobic pretreatment of these wastewaters is rich in hydrogen sulfide that needs to be removed to enable application of the biogas. Nitrogen elimination is traditionally achieved by subsequent nitrification and denitrification of the effluent of the anaerobic reactor. Alternatively, the hydrogen sulfide in the biogas can be applied as an electron donor in an autotrophic post-denitrification step. In order to study whether sufficient hydrogen sulfide containing biogas for denitrification was produced in the anaerobic reactor, the biogas composition as a function of the anaerobic reactor-pH was estimated based on a typical wastewater composition and chemical equilibrium equations. It is demonstrated that typical sulfate and nitrogen concentrations in fish cannery wastewater are highly appropriate for application of autotrophic post-denitrification. A literature review furthermore suggested that the kinetic parameters for autotrophic denitrification by Thiobacillus denitrificans represent no bottleneck for its application. Initial experimental studies in fixed-film reactors were conducted with sodium sulfide and nitrate as an electron donor-acceptor couple. The results revealed that only moderate volumetric treatment capacities (1 g-NO3- N l(-1) day(-1)) could be achieved. Mass balances suggested that incomplete sulfide oxidation to elemental sulfur occurred, limiting biomass retention and the treatment capacity of the reactor. Future research should clarify the questions concerning product formation from sulfide oxidation.

Stringent environmental laws in Europe and Northern America lead to the development towards closure of the process water streams in pulp and paper mills. Application of a "zero-discharge" process is already a feasible option for the board and packaging paper industry, provided in-line treatment is applied. Concomitant energy conservation inside the mill results in process water temperatures of 50-60 degrees C. Thermophilic anaerobic treatment complemented with appropriate post-treatment is considered as the most cost-effective solution to meet re-use criteria of the process water and to keep its temperature. In the proposed closed-cycle, the anaerobic treatment step removes the largest fraction of the biodegradable COD and eliminates "S" as H2S from the process stream, without the use of additional chemicals. The anaerobic step is regarded as the only possible location to bleed "S" from the process water cycle. In laboratory experiments, the effect of upward liquid velocity (Vupw) and the specific gas loading rate (Vgas) on the S removal capacity of thermophilic anaerobic bio-reactors was investigated. Acidifying, sulphate reducing sludge bed reactors were fed with partly acidified synthetic paper mill wastewater and were operated at 55 degrees C and pH 6. The reactors were operated at organic loading rates up to 50 g COD.l-1.day-1 at COD/SO4(2-) ratios of 10. The effect of Vupw was researched by comparing the performance of a UASB reactor operated at 1.0 m.h-1 and an EGSB reactor, operated at 6.8 m.h-1. The Vupw had a strong effect on the fermentation patterns. In the UASB reactor, acidification yielded H2, acetate and propionate, leading to an accumulation of reducing equivalents. These were partly disposed of by the production of n-butyrate and n-valerate from propionate. In the EGSB reactor net acetate consumption was observed as well as high volumetric gas (CO2 and CH4) production rates. The higher gas production rates in the EGSB reactor resulted in higher S-stripping efficiencies. The effect of Vgas was further researched by comparing 2 UASB reactors which were sparged with N2 gas at a specific gas loading rate of 30 m3.m-2.day-1. In contrast to the regular UASB reactors, the gas-supplied UASB showed a more stable performance when the organic loading rates were increased. Also, the H2S stripping efficiency was 3-4 times higher in the gas-supplied UASB, reaching values of 67%. Higher values were not obtained owing to the relatively poor sulphate reduction efficiencies.

Measurement of oxalate in urine is important for the diagnosis of primary hyperoxaluria (McKusick 259900) and the secondary forms produced by excessive intake or abnormal intestinal absorption of oxalate (1). Determination of glycolic acid is essential for the diagnosis of primary hyperoxaluria type 1. Finally, to estimate the risk of stone formation in calcium oxalate urolithiasis and nephrocalcinosis, simultaneous determination not only of calcium but also of citrate (a potent inhibitor of calcium oxalate and calcium phosphate crystallization) and other constituents (electrolytes, phosphate and sulfate) is required to calculate urinary calcium saturation (2). Ion-chromatography HPLC (3)(4) and specific enzymatic assays (5)(6) are available only in specialized laboratories. In addition, preservation and storage of liquid samples may influence the stability of oxalate and glycolate (7). Use of urinary filter spots is a practical alternative for the collection and safe transport of samples to be analyzed for many metabolic disorders. To evaluate the age-related changes of oxalate, glycolate, citrate, and sulfate in a pediatric population, we developed an automated ion-chromatography system for the simultaneous measurement of these anions in urine and established their reference values for liquid urine samples as well as for dried urine on filter paper. We studied 20 individuals from each age group ( 16 years), all without renal or metabolic disease, all on a routine food intake at the time of study. The urines were preserved with 6 mol/L HCl at pH 1–2 to prevent nonenzymatic conversion of ascorbate to oxalate. Filter paper strips (3 × 5 …

The effect of 22 technological waste water samples and of some standards was tested on bacteria, fungi, chlorococcal algae, flagellata, plant cells, cells of Tubifex tubifex, hamster cells V79 and the fish Lebistes reticulatus. Of these 22 samples, some inhibition of cell life processes was displayed by the black liquor formed in the production of paper pulp and viscose pulp, by the waste solution produced during the preparation of bleaching agents for paper pulp and viscose pulp, and by the residual liquor after hypochlorite treatment of paper pulp.

Toxic effects of unbleached (sulfate or sulfite) and bleached (sulfate) paper mill effluents were studied in a primary culture of rainbow trout liver cells. The effluents and control water from a clean area were extracted with diethyl ether and added to the cultures dissolved in dimethyl sulfoxide. Plasma membrane integrity was studied by measuring lactate dehydrogenase (LDH) leakage. The cellular content of glutathione (GSH) was used as an indicator of oxidative stress and the formation of reactive intermediates. Dose-response studies indicated that unbleached effluents contained more potent toxic substances than bleached effluents. Both unbleached and bleached effluents contained organic diethyl ether-extractable substances which increased cytochrome P450-dependent 7-ethoxyresorufin-O-deethylase (EROD) activities. The inducing effects were seen at concentrations substantially lower than those decreasing GSH content and increasing LDH leakage. Possible EROD inducing substances in bleached effluents are chlorinated organic compounds. Inducing compounds in unbleached effluents are yet to be identified. Furthermore, at higher concentrations the effluents contained substances that inhibited the cytochrome P450 system. The results show that the trout primary hepatocyte cultures afford a convenient in vitro method for screening cytochrome P450 inducing components extracted from industrial effluents to investigate mechanisms by which wastewaters cause injury in cells.