Bleached Kraft Pulp Mill Effluent Research Articles

Use of paired fathead minnow (Pimephales promelas) reproductive test. Part 1: Assessing biological effects of final bleached kraft pulp mill effluent using a mobile bioassay trailer system

Reproductive effects have been recorded in wild fish in waters receiving pulp mill effluent (PME) since the mid to late 1980s. Laboratory assays with fathead minnow (FHM; Pimephales promelas) have been developed to better understand fish responses to PME. However, observations from laboratory studies have been variable, making it difficult to establish cause/effect relationships. A lack of environmental relevance in these laboratory studies may have contributed to the variability observed. The objectives of the present study were, first, to determine the effects of bleached kraft PME (BKME) on FHM under environmentally realistic conditions (i.e., ambient water and effluent quality) and, second, to determine the suitability of pair-breeding FHM to better link BKME-induced changes in indicators at the biochemical, individual, and population levels. A mobile bioassay trailer was situated on-site at a bleached kraft mill for 60 d, allowing supply of both ambient water (Lake Superior, Canada) and final BKME. The reproductive output of FHM was initially assessed for 21 d to obtain baseline data pre-exposure. At the end of the pre-exposure period, selected breeding pairs were exposed to final BKME (100% v/v and 1% v/v) for 21 d. Results demonstrated a stimulatory response pattern at 1% BKME (e.g., increased egg production) compared to control. In the 100% treatment, spawning events were reduced and fewer eggs were produced during the first two weeks of exposure. Exposure to 100% (v/v) BKME also resulted in ovipositor development in males and development of male secondary sex characteristics in females. Obtaining pre-exposure data and use of pair-breeding FHM in this assay gave a sensitive indication of effluent effects and allowed accurate comparisons of endpoints to be made.

Combined effects of pulp and paper effluent, dehydroabietic acid, and hypoxia on swimming performance, metabolism, and hematology of rainbow trout

Experiments were conducted to examine the effects of a thermomechanical (TMP)/bleached kraft pulp and paper mill effluent (BKME), dehydroabietic acid (DHAA), hypoxia, and combinations of hypoxia and effluent on juvenile rainbow trout. In the first two experiments, trout were exposed for 4 weeks to 0%, 10%, 30%, and 70% TMP/BKME or 0, 35, 110, and 250 μg L −1 DHAA, respectively. Endpoints of those dose–response studies included critical swimming speed, oxygen consumption, and hematology. Reduced swimming performance was found for fish exposed to 70% TMP/BKME. Moderate increases in mean cell hemoglobin concentration at 70% TMP/BKME and blood glucose at 30% and 70% TMP/BKME were also seen. The opposite trend for glucose was found for DHAA-exposed fish, where a slight decrease in glucose was seen at 110 and 250 μg L −1 DHAA. The third experiment examined the effects of 15% v/v TMP/BKME exposure at 2.5 and 5.0 mg L −1 dissolved oxygen (DO) for 4 weeks. This experiment found no effect of low DO on swimming ability. An interactive effect between DO and effluent exposure was seen only on hematocrit, where effluent caused an increase in hematocrit at 5 mg L −1 and a decrease at 2.5 mg L −1 DO. Effluent exposure in this experiment resulted in a greater number of smaller red blood cells. The current study demonstrated physiological effects in rainbow trout exposed to varying concentrations (15–70% v/v) of a TMP/BKME and no substantial effects of DHAA exposure. With the exception of the reduced swimming performance in fish exposed to TMP/BKME, the observed effects are considered relatively small in magnitude but are occurring at concentrations of effluent that occur in the receiving environment.

Responses of European eel ( Anguilla anguilla L.) circulating phagocytes to an in situ closed pulp mill effluent exposure and its association with organ-specific peroxidative damage

The effect of bleached kraft pulp mill effluent (BKPME) persistent compounds on phagocyte activities and its organ-specific influence in gill, kidney and liver was studied in European eel (Anguilla anguilla L.). Eels were caged and plunged at 3 different sites—50 m (site 1), 100 m (site 2) and 2000 m (site 3) away from the end of the closed BKPME discharging channel for 8 and 48 h. Gill, head kidney and peritoneum phagocytes oxidative burst activity (OBA) was measured by the nitroblue tetrazolium reduction assay whereas lipid peroxidation (LPO) in eel gill, kidney and liver was measured by thiobarbituric acid reaction. A significant gill OBA induction was found at 8 h on site 2, and on sites 1, 2 and 3 at 48 h exposure. However, in head kidney and peritoneal exudate phagocytes, OBA induction was significant only at sites 2 and 3 after 48 h exposure. In those particular sites, a significant increase in gill, kidney and liver LPO was measured that is assumed to result from OBA induction. Considering OBA and LPO, gill is the most affected tissue compared to kidney and liver. Gill vulnerability towards peroxidative damage was demonstrated at 8 h on site 2 and at 48 h on sites 1, 2 and 3, whereas in kidney was observed at sites 2 and 3 only at 48 h. Liver LPO increased at site 2 only after 48 h exposure. Our results demonstrate that the OBA activation pattern in gill and kidney is associated with the induced peroxidative damage extent in those organ, together with water pollution the exposure route, resulting from previous BKPME effluent sediment contamination which may affect the activation pattern of circulating fish phagocytes.

Detecting p53 family proteins in haemocytic leukemia cells ofMytilus edulisfrom Pictou Harbour, Nova Scotia, Canada

Evaluating patterns of expression of p53-related proteins in cells is a novel approach in defining environmentally linked diseases. We have examined the induction of haemocytic leukemia in Mytilus edulis by municipal and industrial contaminants in Pictou Harbour, Nova Scotia, Canada. We used a murine monoclonal antibody, 1E10, as a diagnostic reagent to detect leukemic cells. We first characterized the reactivity of 1E10 with both normal and leukemic Mytilus haemocytes by confocal microscopy. We then compared p53 gene family expression (p53, p63–p73, and p97) in normal versus leukemic haemocytes using a panel of monoclonal and polyclonal antibodies to p53 family proteins. The immunochemical data demonstrate that haemocytic leukemia cells of M. edulis differentially express p63–p73 and p97–p120 proteins. We subsequently used 1E10 to diagnose haemocytic leukemia in 500 M. edulis previously deployed 6 months earlier in Pictou Harbour. In the field, Mytilus caged near untreated municipal wastewater and bleached kraft pulpmill effluents have a significantly greater chance of developing haemocytic leukemia than do mussels exposed to reference sites.

Gill morphometry and hematology of juvenile chinook salmon chronically exposed to treated (elemental chlorine-free) bleached kraft pulp mill effluent at low temperature to simulate winter exposure

We used an on-site mobile laboratory to assess the effects of pulp mill effluent on juvenile (~0.9 g) chinook salmon, Oncorhynchus tshawytscha (Walbaum in Artedi, 1792), that normally overwinter under ice in the upper Fraser River at Prince George, British Columbia. After a 28-day exposure at 0.4–2.7 °C to secondary-treated bleached kraft mill effluent (TBKME; 0%, 2%, 4%, 8%, or 16%) under both normoxic and hypoxic (~67% air saturation) conditions, hematocrit (Hct), leucocrit (Lct), and differential white blood cell counts were determined and gills were examined for gross and fine morphometry. TBKME had no effect on either Hct or Lct, but the highest TBKME concentration (16%) increased lymphocyte numbers, reduced secondary lamellae numbers, and increased the blood–water diffusion distance of secondary lamellae. Given the relatively high TBKME concentration, compared with actual discharges to the river, and the small physiological changes observed, it appears that chronic winter exposure of juvenile chinook salmon to TBKME under hypoxic winter conditions is unlikely to produce major disturbances to these aspects of the fish's physiology.

Responses of European eel ( Anguilla anguilla L.) in two polluted environments: in situ experiments

European eels ( Anguilla anguilla L.) were caged for 8 and 48 h in two polluted areas to assess the contamination cleanup process in the Vouga River 2 years after the official closing of a bleached kraft pulp mill effluent (BKPME; experiment 1), and to monitor the effects induced by contaminated offward fishing harbor waters (experiment 2). Plasma cortisol, glucose, and lactate were evaluated as stress responses. In experiment 1, plasma cortisol, glucose, and lactate increased after 8 h of exposure in site 3, which is located farthest from the deactivated sewage outlet. However, A. anguilla seemed to adapt after 48 h of exposure in site 3, because all three parameters returned to control levels. Plasma glucose also significantly increased after 8 h of exposure at sites 1, 2, and 3, returning to control levels after 48 h. Plasma lactate levels increased after 8 h of exposure at site 3 and after 48 h of exposure at site 1. In experiment 2, A. anguilla exposed to contaminated harbor waters increased their plasma lactate after 8 and 48 h of exposure, whereas their cortisol and glucose plasma were elevated only after 48 h of exposure. The results demonstrate that even 2 years after the official closing of the BKPME sewage outlet, the river Vouga water remains contaminated by the sediment associated chemicals. Because the fishing harbor induced in A. anguilla the same type of stress responses, it is also an area of concern. The adopted stress parameters allied to a caging strategy are recommended for future environmental monitoring assessments.

Anguilla anguilla L. antioxidants responses to in situ bleached kraft pulp mill effluent outlet exposure

This study assesses the antioxidant enzymes activities viz., catalase, glutathione peroxidase, glutathione S-transferase and nonenzymatic antioxidant molecule such as glutathione in Anguilla anguilla L. gill, kidney and liver in response to 8- and 48-h exposure to bleached kraft pulp mill effluent (BKPME). A. anguilla were caged and plunged at three different sites—50 (Site 1), 100 (Site 2) and 2000 m (Site 3) away from the closed BKPME outlet. A significant gill (8 and 48 h) and kidney (48 h) catalase activity decrease was observed at site 2 exposure whereas liver showed a significant increase in catalase activity after 8 and 48 h to site 1 exposure. Glutathione peroxidase (GPX) activity was significantly decreased in gill after 8-h exposure to site 1 and 48-h exposures to sites 1 and 2, respectively. Concerning gill, kidney and liver glutathione S-transferase (GST) activity, a significant gill GST activity decrease after 8 h at site 2 and 48 h at sites 1 and 2 was observed; in kidney, a significant decrease in its activity was observed after 48 h at sites 1 and 2, respectively, whereas in liver, the decrease was significant only at site 2 after 48-h exposure. The in situ BKPME exposure caused a significant total gill and kidney reduced glutathione (GSH) decrease after 8 h at site 2 exposure and after 48 h at site 1 and 2 exposures, respectively. However, a biphasic response was observed in liver, i.e. initial significant increase after 8 h at site 2 followed by a significant decrease after 48 h to the same site exposure. The enzymatic and nonenzymatic antioxidants pattern in gill and kidney, as observed in this study, was different than liver, demonstrating that the liver was more resistant to oxidative damage than gill and kidney. In addition, A. anguilla gill, kidney and liver antioxidants adaptation potentials may serve as a surrogate biomarker to BKPME exposure.

Spectroscopic characteristics of ultrafiltration fractions of fulvic and humic acids isolated from an eucalyptus bleached Kraft pulp mill effluent

In order to investigate the chemical heterogeneity of fulvic and humic acids previously isolated from a bleached Kraft pulp mill effluent, a sequential ultrafiltration (UF) scheme through four polyethersulphone membranes was applied. The unfractionated fulvic and humic acids and their fractions were characterized by UV-VIS, synchronous fluorescence (with Δ λ=60 nm) and FTIR spectroscopies. The FTIR spectra were compared with those of lignin isolated from Eucalyptus globulus wood and from the black liquor of a Kraft pulping process. The results highlighted that fulvic acids fractions of low molecular sizes contain more lignin derived phenolic units, while those of higher molecular size exhibit a higher content of carbohydrate structures. However, the shift observed in the UV-VIS absorbance and fluorescence intensity towards higher wavelength, suggests a higher degree of conjugation of π-bonds in the fractions of highest molecular sizes. In what concerns the humic acids size fractions, the FTIR spectra did not exhibit major differences but, as observed for the fulvic acids’ fractions, UV-VIS and synchronous fluorescence spectra also suggest a higher degree of conjugation of π-bonds in the fractions with the highest molecular sizes. It was also observed that the fulvic and humic acids fractions of the same molecular size, operationally defined by the UF process, exhibit major differences in their spectroscopic features.

Peroxisome proliferation as a biomarker in environmental pollution assessment.

Peroxisome proliferators comprise a heterogeneous group of compounds known for their ability to cause massive proliferation of peroxisomes and liver carcinogenesis in rodents. In recent years it has become evident that other animals may be threatened by peroxisome proliferators, in particular aquatic organisms living in coastal and estuarine areas. These animals are exposed to a variety of pollutants of industrial, agricultural and urban origin which are potential peroxisome proliferators. Both laboratory and field studies have shown that phthalate ester plasticizers, PAHs and oil derivatives, PCBs, certain pesticides, bleached kraft pulp and paper mill effluents, alkylphenols and estrogens provoke peroxisome proliferation in different fish or bivalve mollusc species. The response appears to be mediated by peroxisome-proliferator activated receptors, members of the nuclear receptor family, recently cloned in fish. Based on these results it is proposed that peroxisome proliferation could be used as a biomarker of exposure to a variety of pollutants in environmental pollution assessment. This is illustrated by a case study in which mussels, used worldwide as sentinels of environmental pollution, were transplanted from reference to contaminated areas and vice versa. In mussels native to an area polluted with PAHs and PCBs, peroxisomal acyl-CoA oxidase (AOX) activity and peroxisomal volume density were 2-3 fold and 5-fold higher, respectively, compared to the reference site. When animals were transplanted to the polluted station, with increased concentration of organic xenobiotics, a concomitant significant increase of AOX was recorded. Conversely, in animals transplanted to the cleaner station, AOX activity and peroxisomal volume density decreased significantly. These results indicate that peroxisome proliferation is a rapid (i.e., two days) and reversible response to pollution in mussels. Before peroxisome proliferation can be implemented as a biomarker in biomonitoring programs, a well-defined protocol should be established and validated in intercalibration and quality assurance programmes. Furthermore, the influence of biotic and abiotic factors, some of which are known to affect peroxisome proliferation (season, tide level, interpopulation and interindividual variability), should be taken into consideration. The possible hepatocarcinogenic effects as well as the potential adverse effects on reproduction, development, and growth of peroxisome proliferators are unknown in aquatic organisms, thus providing a challenge for future investigations.

Identification and confirmation of traces of chlorinated fatty acids in fish downstream of bleached kraft pulp mills by gas chromatography with halogen-specific detection

Methyl esters of threo-9,10-dichlorooctadecanoic, threo-7,8-dichlorohexadecanoic, and threo-5,6-dichlorotetradecanoic acids, present in transesterified extracts of filets, gonad, intestinal fat and carcass of white sucker ( Catostomus commersoni) sampled in receiving waters of bleached kraft pulp mill effluents, were identified by gas chromatography with halogen-specific detection (XSD). Identification was based on (1) a comparison of the retention times of a sample peak with a prospective reference standard on two stationary phases of very different polarities by spiking, and (2) elution behavior of configurational and positional isomers of dichloro fatty acid methyl esters.

Genotoxic and hepatic biotransformation responses induced by the overflow of pulp mill and secondary-treated effluents on Anguilla anguilla L.

Pulp and paper mill effluent compounds pollute the aquatic environment and are responsible for increased biochemical alterations and genotoxicity in aquatic organisms such as fish. Adult eels ( Anguilla anguilla L) were exposed during 8, 16, 24, and 72 h to the following conditions: (1) aerated, filtered, and dechlorinated tap water ( C); (2) 2.5% (v/v) sewage water previously treated with activated sludge ( T); (3) bleached kraft pulp and paper mill effluent collected at the river Vouga, close to an ancient sewage outlet (Portucel), diluted in tap water [25% ( E 25 ) and 50% ( E 50 )]; and (4) bleached kraft pulp and paper mill effluent sediment [water-soluble fraction ( S)]. Liver biotransformation induced by the above conditions was measured as ethoxyresorufin- O-deethylase (EROD), cytochrome P450 (P450) (Phase I), and glutathione- S-transferase (GST) (Phase II). Genotoxicity was also determined as blood/liver DNA strand breaks and erythrocytic nuclear abnormalities (ENA) induced on European eel ( A. anguilla L). Liver EROD activity was significantly increased in eels at 8 and 16 h exposure to E 25 , as well as at 16, 24, and 72 h exposure to E 50 . S exposure induced liver EROD activity only at 24 h. A significant decrease in liver P450 was observed at 72 h exposure to T, whereas a significant P450 increase at 16 h was followed by a significant decrease at 24 h exposure to E 25 . Another P450 significant increase was noticed at 72 h exposure to S. Liver GST activity (Phase II) demonstrated a significant increase at 72 h exposure to E 50 and to S. A significant decrease in blood DNA integrity was observed at 72 h exposure to T and at 24 and 72 h to S. Blood DNA integrity significantly decreased at 16 and 24 h exposure to E 25 , as well as at 8, 16, and 24 h exposure to E 50 . Liver DNA integrity significantly decreased at 72 h exposure to T and at 16 h exposure to S. Moreover , liver DNA integrity was significantly decreased at 24 h exposure to E 25 and E 50 , and 72 h to E 50 . A. anguilla L. increased ENA frequency was detected in T at 16, 24, and 72 h, whereas in E 25 and S it was observed at 8, 16, and 24 h. Furthermore, E 50 ENA frequency increased at 24 h exposure.

Biotransformation, genotoxic, and histopathological effects of environmental contaminants in European eel ( Anguilla anguilla L.)

A prolonged toxicity study was carried out in young European eel ( Anguilla anguilla L.) to evaluate the effects of environmental contaminants, namely, two individual standard compounds, benzo[ a]pyrene (BaP) and dehydroabietic acid (DHAA), and a complex mixture, bleached kraft pulp mill effluent (BKPME). Fish were exposed to BaP (0.22, 0.45, and 0.9 μM) and BKPME (3.12%, 6.25%, and 12.5% (v/v)) for 3, 7, and 30 days and to DHAA (0.07, 0.15, and 0.30 μM) for 3, 7, 30, 90, and 180 days. The biomarkers include biotransformation and genotoxicity indicators, such as total ethoxyresorufin O-deethylase (EROD) activity and frequency of erythrocytic nuclear abnormalities (ENAs), respectively. Hematological dynamics was assessed as frequency of immature erythrocytes (IEs). Histopathological examinations were carried out for the highest concentrations and for 30 days and longer exposures. Total EROD increases significantly only after 180 days of DHAA exposure. However, significant ENA induction was generally observed during exposure to all contaminants tested. Nevertheless, some of the ENA results suggest an altered genotoxic response, which may arise either from short-term exposures to the highest contaminant levels or long-term exposures to the lowest contaminant levels. IE frequency decreased significantly after 30 days of exposure to 0.45 μM BaP and 180 days of exposure to the entire DHAA concentration range. Increased density of pigmented macrophage aggregates in 30-day BaP- and BKPME-exposed fish as well as in 90- and 180-day DHAA-exposed fish confirmed histopathological liver alterations. Bile accumulation in hepatocytes after BaP treatment, cytoplasmic vacuolization and cell atrophy following DHAA exposure, as well as liver loss of parenchymal cells in BKPME-exposed fish, were also detected. Dispersed necrosis and focal inflammation were observed in the livers of all treated groups. Fish exposed to DHAA and BKPME showed skin and gill disruption as well as kidney Malpighian corpuscle alterations. All 30-day-treated groups revealed intense spleen hemosiderosis, indicating increased erythrophagia. This splenic effect may be strongly correlated with the observed disappearance of ENAs. Neoplastic lesions were not found. A multibiomarker strategy, which includes EROD, ENA, and IE assays as well as histopathological studies, contributed to a better understanding of the global toxic process.

Engineering bacterial strains through the chromosomal insertion of the chlorocatechol catabolism tfdI CDEF gene cluster, to improve degradation of typical bleached Kraft pulp mill effluent pollutants

Chloroaromatic pollutants from bleached Kraft pulp mill effluents (BKME) are difficult to degrade, because bacterial strains present in BKME aerobic treatments, only partially degrade these compounds, accumulating the corresponding chlorocatechol intermediates. To improve the catabolic performance of chlorocatechol-accumulating strains, we introduced, by chromosomal insertion, the tfd I CDEF gene cluster from Ralstonia eutropha JMP134 (pJP4). This gene cluster allows dechlorination and channelling of chlorocatechols into the intermediate metabolism. Two bacterial strains, R. eutropha JMP222 and Pseudomonas putida KT2442, able to produce chlorocatechols from 3-chlorobenzoate (3-CB) were used. Acinetobacter lwoffii RB2 isolated from BKME by its ability to grow on guaiacol as sole carbon source and shown to be able to produce the corresponding chlorocatechols from the BKME pollutants 4-, and 5-chloroguaiacol, was also used. The tfd I CDEF gene cluster was inserted in the chromosome of these strains using mini Tn 5-derived vectors that allow expression of the Tfd enzymes driven by the lac I q /P trc or tfd R/P tfd-I regulatory systems, and therefore, responding to the inducers isopropyl-s-D-thiogalactopyranoside (IPTG) or 3-CB, respectively. Crude extracts of cells from strains JMP222, KT2442 or RB2 engineered with the tfd genes, grown on benzoate and induced with IPTG or 3-CB showed Tfd specific activities of about 15% - 80% of that of the strain JMP134. Dechlorination rates for 3-CB or chloroguaiacols correlated with levels of Tfd enzymes. However, none of the strains containing the chromosomal copy of the tfd I CDEF cluster grew on monochloroaromatics as sole carbon source. Experiments with BKME aerobic treatment microcosms showed that the catabolic performance of the engineered bacteria was also lower than the wild-type R. eutropha strain JMP134.

Engineering bacterial strains through the chromosomal insertion of the chlorocatechol catabolism tfdICDEF gene cluster, to improve degradation of typical bleached Kraft pulp mill effluent pollutants

Chloroaromatic pollutants from bleached Kraft pulp mill effluents (BKME) are difficult to degrade, because bacterial strains present in BKME aerobic treatments, only partially degrade these compounds, accumulating the corresponding chlorocatechol intermediates. To improve the catabolic performance of chlorocatechol-accumulating strains, we introduced, by chromosomal insertion, the tfd I CDEF gene cluster from Ralstonia eutropha JMP134 (pJP4). This gene cluster allows dechlorination and channelling of chlorocatechols into the intermediate metabolism. Two bacterial strains, R. eutropha JMP222 and Pseudomonas putida KT2442, able to produce chlorocatechols from 3-chlorobenzoate (3-CB) were used. Acinetobacter lwoffii RB2 isolated from BKME by its ability to grow on guaiacol as sole carbon source and shown to be able to produce the corresponding chlorocatechols from the BKME pollutants 4-, and 5-chloroguaiacol, was also used. The tfd I CDEF gene cluster was inserted in the chromosome of these strains using mini Tn 5-derived vectors that allow expression of the Tfd enzymes driven by the lac I q /P trc or tfd R/P tfd-I regulatory systems, and therefore, responding to the inducers isopropyl-ß-D-thiogalactopyranoside (IPTG) or 3-CB, respectively. Crude extracts of cells from strains JMP222, KT2442 or RB2 engineered with the tfd genes, grown on benzoate and induced with IPTG or 3-CB showed Tfd specific activities of about 15% - 80% of that of the strain JMP134. Dechlorination rates for 3-CB or chloroguaiacols correlated with levels of Tfd enzymes. However, none of the strains containing the chromosomal copy of the tfd I CDEF cluster grew on monochloroaromatics as sole carbon source. Experiments with BKME aerobic treatment microcosms showed that the catabolic performance of the engineered bacteria was also lower than the wild-type R. eutropha strain JMP134.

Impact of Bleached Kraft Pulp Mill Effluent on the Nearshore Benthic Community of Jackfish Bay, Lake Superior

Abstract We assessed the impact of bleached kraft pulp mill effluent on benthic invertebrate community structure in the shallow (1 m) nearshore waters of Jackfish Bay, Lake Superior. Duplicate benthic samples were collected from 0.5 m2 quadrats at twenty-three stations along two shorelines of Jackfish Bay up to 1800 m from the point of effluent discharge, and from a reference station located within the Jackfish Bay study area. Detrended correspondence analysis (DCA) revealed a gradient of stations on both shorelines which was strongly correlated with distance from effluent outfall and hence exposure to the effluent plume. Within this gradient were two distinct clusters of stations. The first cluster contained all but one station on both shores <300 m from the outfall; these stations receive constant exposure to the effluent and were dominated (>90%) by tubificids (Limnodrilus hoffmeisteri, Tubifex tubifex, T. ignotus and Spirosperma ferox) and the naidid Chaetogaster diaphanus. The second cluster contained all stations on both shores >300 m from the outfall; community structure at these stations was generally comparable to that at the reference site and was characterized by several species of Chironomidae, C. diaphanus and Nais barbata, and low numbers of several insect taxa. The results of this study show that benthic community structure in nearshore environments can be significantly impacted by pulp mill effluent and should be considered in monitoring assessments. At Jackfish Bay, such impacts appear to be restricted primarily to within the first 500 m of effluent discharge.

Microsomal monooxygenase activity in Tilapia ( Oreochromis mossambicus) exposed to a bleached kraft mill effluent using different exposure systems

Bleached kraft pulp and paper mill effluents (BKMEs) are known to have adverse effects on aquatic organisms. One of the effects of BKMEs is its ability to induce cytochrome P4501A activity in exposed fish. 7-ethoxyresorufin O-deethylase (EROD) activity is the most common biomarker used to measure the mixed-function monooxygenase activity. In this study, Tilapia were exposed to BKMEs using different exposure systems and their hepatic EROD activity, as well as liver/somatic index (LSI), were determined. In the Phase I study, Tilapia treated with βNF and a whole (100%) BKME using a static, non-renewal system exhibited statistically significant EROD induction, but LSI values were not altered. In the Phase II study, fish were either caged in the mill's fishpond with the whole effluent passing through or cultured in tanks receiving 100% of the BKME continuously using a flow-through system in the laboratory. Their EROD activities were then compared with the non-exposed fish (control). The EROD activities in both groups of fish were elevated significantly with the greatest induction being observed in the field-exposed group. The LSI values in all of the field-exposed fish were significantly greater than the control Tilapia. The EROD assay was sensitive in detecting biological changes in fish exposed to the BKME. Further studies are warranted to better understand the impacts of BKMEs on aquatic organisms in Taiwan.

A Review of the Evidence for Endocrine Disruption in Canadian Aquatic Ecosystems

Abstract Endocrine disrupting substances in the environment and the potential affects they have on wildlife species has recently received increased public attention. This paper provides background information on research that has addressed the endocrine disruption issue in the Canadian aquatic environment as well as information on studies that are presently being conducted within the country to address this issue. Two of the three studies from across the world often cited as presenting sufficient evidence for connecting contaminants and endocrine disruption in fish populations are Canadian — Lake Ontario lake trout and TCDD and related compounds, and white sucker exposed to bleached kraft pulp mill effluent. Several other Canadian examples exist, including altered stress responses in yellow perch exposed to heavy metals, altered smoltification in Atlantic salmon exposed to 4-nonylphenol and imposex in dogwelks exposed to tributyltin. While other Canadian studies suggest alterations in reproductive function in fish, direct links to contaminants have not been made. Other studies have identified endocrine active compounds in the receiving environments but have yet to link these to alterations in endocrine function in resident fish populations. The strength of Canada's research programs lies in the breadth and depth of their field related research. It is this world-recognized expertise and strength that Canada can contribute to the international effort to address the endocrine disruptor issue.

Identification and treatment of a waste stream at a bleached‐kraft pulp mill that depresses a sex steroid in the mummichog (Fundulus heteroclitus)

AbstractChanges to indicators of reproductive performance have been documented in fish exposed to some bleached kraft pulp mill effluents (BKPMEs). However, responses are not consistent across mill types or processes. It is not clear where the sources of the effects are within mills, what the causative compounds are, or what process changes are effective to remove these sources. Our previous studies suggested that condensates were a source of compounds that reduced plasma testosterone in the mummichog (Fundulus heteroclitus). Results also suggested that reverse osmosis (RO) treatment of condensates removed this source. The objective of this study was to use a toxicity identification evaluation approach and expose mummichog to various waste streams in the laboratory to identify the effluent source that depressed plasma testosterone in the mummichog and the effects of RO treatment. In 7‐ and 21‐d exposures, mummichog were exposed to dilutions of RO feed condensate, RO permeate, combined mill effluent (CME), and final effluent. Results confirmed that condensates depressed plasma testosterone in mummichog. Chemical characterization of the condensate indicated that plant phytosterols were likely not the responsible compounds. Results also confirmed that RO treatment removed the potential of the condensates to depress plasma testosterone in mummichog at environmentally relevant concentrations of final mill effluent (1%).

Identification and treatment of a waste stream at a bleached-kraft pulp mill that depresses a sex steroid in the mummichog (Fundulus heteroclitus).

Changes to indicators of reproductive performance have been documented in fish exposed to some bleached kraft pulp mill effluents (BKPMEs). However, responses are not consistent across mill types or processes. It is not clear where the sources of the effects are within mills, what the causative compounds are, or what process changes are effective to remove these sources. Our previous studies suggested that condensates were a source of compounds that reduced plasma testosterone in the mummichog (Fundulus heteroclitus). Results also suggested that reverse osmosis (RO) treatment of condensates removed this source. The objective of this study was to use a toxicity identification evaluation approach and expose mummichog to various waste streams in the laboratory to identify the effluent source that depressed plasma testosterone in the mummichog and the effects of RO treatment. In 7- and 21-d exposures, mummichog were exposed to dilutions of RO feed condensate, RO permeate, combined mill effluent (CME), and final effluent. Results confirmed that condensates depressed plasma testosterone in mummichog. Chemical characterization of the condensate indicated that plant phytosterols were likely not the responsible compounds. Results also confirmed that RO treatment removed the potential of the condensates to depress plasma testosterone in mummichog at environmentally relevant concentrations of final mill effluent (1%).

Biomonitoring of heavy metals and organo-chlorinated compounds in a pulp mill effluent using introduced mussels

A bleached kraft pulp mill discharges a vast array of substances and special attention should be given to heavy metals and organo-chlorinated compounds. They can persist in nature for a long period of time, are toxic to the wildlife community in certain concentrations, and can be incorporated into the food chain. The aim of this work is to monitor the quality of a bleached kraft pulp mill effluent using filter-feeding molluscs. Transplanted mussels were collected seasonally and analyzed for copper, zinc, cadmium, lead, manganese, iron, dioxins, furans and pentachlorophenol. All of the concentrations in mussels were low even when the mill operated different process types and production, and also during maintenance shut-downs.