Physiological response of carp,Cyprinus carpio,exposed to raw sewage containing fish processing wastewater

Physiological changes of carp exposed to raw sewage were investigated by the use of clinical examination methods. All carp exposed to raw sewage died within 6 h. On hour 48, 10, 40, and 90% of exposed carp survived in 60, 20, and 10% sewage, respectively. Carp exposed to 50 and 20% sewage increased ammonia, glucose, Mg, Cu, and Br, and decreased Fe and Zn in plasma. Even in 10% sewage, ammonia, glucose, and Br in plasma increased. Forty-eight hours of exposure to 50 and 20% sewage caused severe pathological changes in the gills. In the kidney, light abnormalities were observed at this time. When exposed to 50 and 20% sewage, atrioventricular conduction time and duration of electrical systole measured by electrocardiogram shortened briefly, and then extended gradually. In 50 and 20% sewage, heart rate and respiratory frequency increased briefly, and then decreased gradually. Cough reaction increased with the exposure. © 1997 by John Wiley & Sons, Inc. Environ Toxicol Water Qual 12: 1–9, 1997     

Changes in behavior and hematological parameters of freshwater African catfish Clarias gariepinus (Burchell 1822) following sublethal exposure to chloramphenicol

Abstract

The present study was aimed at evaluating the effects of different concentrations of the most commonly used fish antimicrobial drug, chloramphenicol (CAP), on the behavior and hematological parameters of Clarias gariepinus. Fish specimens were exposed to three (2.5, 5.0 and 10.0?mg?L^?1) sublethal concentrations of CAP and a control. Abnormal behavioral changes were observed in fish exposed to higher concentration of CAP. Blood erythrocytes were sampled on days 1,?5,?10 and 15 postexposure to evaluate hematological parameters. Results showed concentration- and time-dependent significant increase in packed cell volume after day 5 of exposure (p?<?0.05). Hemoglobin values also significantly decreased from day 5, whereas values of mean cellular volume significantly decreased throughout the experimental period (p?<?0.05). A mixed trend was observed in the mean values of red blood cells, white blood cells, mean cellular hemoglobin and mean cellular hemoglobin concentration as well as neutrophils. Activities of lymphocytes were significantly increased in all CAP-treated fish during the exposure period, whereas no significant differences were observed in values of monocytes, eosinophils and basophils among the treatment groups and control. Consequently, precautions must be taken, especially when high concentrations of CAP are used in long-term treatments of C. gariepinus in aquaculture.     

Transient effects of 2,4-dichlorophenoxyacetic acid (2,4-D) exposure on some metabolic and free radical processes in goldfish white muscle

This study aims to assess effects of 96 h goldfish exposure to 1, 10 and 100 mg/L of the herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D), on metabolic indices and free radical process markers in white muscle of a commercial fish, the goldfish Carassius auratus L. Most oxidative stress markers and antioxidant enzymes were not affected at 2,4-D fish treatment. 2,4-D fish exposure induced the elevated levels of total (by 46% and 40%) and reduced (by 77% and 73%) glutathione in muscles of goldfish of 10 mg/L 2,4-D and recovery (after 100 mg/L of 2,4-D exposure) groups, respectively. However, in muscles of 100 mg/L 2,4-D exposed goldfish these parameters were depleted (by 47% and 64%). None of investigated parameters of protein and carbohydrate metabolisms changed in white muscles of 2,4-D exposed fish, with exception of lactate dehydrogenase activity, which was slightly (by 11–15%) elevated in muscles of goldfish exposed to 10–100 mg/L of 2,4-D, but also recovered. Thus, the short term exposure of goldfish to the selected concentrations of 2,4-D does not substantially affect their white muscle, suggesting the absence of any effect under the environmentally relevant concentrations.     

Refuse leachate exposure causes changes of thyroid hormone level and related gene expression in female goldfish (Carassius auratus)

To elucidate the potential thyroid disrupting effects of refuse leachate on females, female goldfish (Carassius auratus) were exposed to 0.5% diluted leachates from each step of a leachate treatment process (i.e. raw leachate before treatment, after membrane bioreactor treatment, and the final treated leachate) for 21 days. Raw leachate exposure caused disturbances in the thyroid cascade of female fish, as evidenced by the elevated plasma 3,3ʹ,5-triiodo-l-thyronine (p < 0.05) and thyroid-stimulating hormone (p < 0.01) levels as well as up-regulated hepatic and gonadal type I deiodinase (p < 0.01), type II deiodinase (p < 0.01) and thyroid receptor (p < 0.05) mRNA levels. Thyroid disrupting potency decreased markedly as raw leachate progressed through the “membrane bioreactor + reverse osmosis” treatment but could still be detected in the treated leachate. As our results indicated, thyroid system in female goldfish was more sensitive to leachate exposure than that of the male fish.     

Sex and low-level sampling stress modify the impacts of sewage effluent on the rainbow trout (Oncorhynchus mykiss) immune system

The objective of the present study was to investigate the influence of chronic exposure to municipal sewage treatment effluent at environmentally relevant concentrations on immune parameters in rainbow trout (Oncorhynchus mykiss), including the assessment of potential differences in reactivity between sexually mature male and female fish. Trout were exposed to 1.5 and 15% (v/v) secondary treated municipal sewage effluent for 32 weeks. Fish were injected intra-peritoneally either with inactivated Aeromonas salmonicida to simulate an infection or with PBS as control for this immune challenge 6 weeks prior to sampling. Exposure to effluent resulted in a decrease in A. salmonicida-specific serum antibody level and blood lymphocyte numbers in mature females, but not in male fish. Injection of A. salmonicida resulted in enhanced serum lysozyme activity in mature male trout, which were not exposed to effluent. This stimulating effect of A. salmonicida could not be found in effluent-exposed trout, again potentially revealing a suppressive effect of the effluent. An influence of sampling fish on two consecutive days was observed in many immune parameters, most likely reflecting handling stress. Leucocyte and lymphocyte numbers in peripheral blood were consistently lower in male and female fish on the second sampling day. Phagocytosis in head kidney macrophages from male trout was also influenced by sampling day, whereby a stimulation of this reaction occurred on the second day of sampling. Liver mixed function oxygenase activity was found to be enhanced in mature male trout exposed to 15% effluent. In conclusion, the study showed, that exposure to sewage treatment plant effluent, in surface water relevant concentrations, can lead to potentially adverse effects on selected immune reactions in rainbow trout. However, this study also demonstrated that both handling stress and the sex of mature fish have distinct influences on the immune response detected in male and female fish and are likely to influence measured immune parameters to the extent that subtle effluent induced changes may be difficult to detect.     

Evaluation of estrogenic activity from a municipal wastewater treatment plant with predominantly domestic input

The purpose of this study was to survey estrogenic releases from two primarily domestic wastewater treatment plants over three seasons (1996-1999). Mature male channel catfish were maintained at two sites within each WWTP and a reference site for 21 days. Estrogenic activity of effluent was assessed by the Yeast Estrogen Screen (YES) assay (in 1999) and the expression of the female egg yolk precursor protein, vitellogenin (Vtg) in caged male channel catfish (1996-1998). Serum Vtg of animals exposed at WWTP-A was induced 220% above reference values in the Fall of 1996 and 480% in Spring of 1997. In animals exposed to effluent of WWTP-B, serum Vtg was elevated 370% in Spring of 1997 and 480% in Fall of 1997 relative to fish held in a reference location. Serum 17-beta-estradiol (E2) levels were also significantly elevated 13 and 16-fold in the Fall 1997 and Summer 1998 in the fish exposed to WWTP-A effluent. A 13.5-fold increase in serum E2 was observed in fish exposed to WWTP-B during Fall 1997. Utilizing an E2 concentration-Vtg response curve generated in the laboratory, effluent from both plants (in 1997 and 1998) had estrogen equivalent values ranging from 23 to 123 ng/l E2 equivalents. These values were comparable with YES values obtained from 1999, which indicated the presence of 21 to 147 ng/l E2 equivalents. E2 was responsible for 3 (fall) to 100% (summer) of the YES activity. Glucuronides of E2 were also observed in the treated effluent. These studies indicate that variable estrogenic activity is present in municipal wastewater resulting from domestic activities and that this activity may be significantly altered by environmental factors.     

Long‐term exposures to di‐n‐butyl phthalate inhibit body growth and impair gonad development in juvenile Murray rainbowfish (Melanotaenia fluviatilis)

The aim of the present study was to evaluate whether long‐term exposures to environmentally relevant concentrations of di‐n‐butyl phthalate (DnBP) disrupt the reproduction‐based endpoints in juvenile Murray rainbowfish (Melanotaenia fluviatilis). Fish were exposed to 5, 15 or 50 µg l^?1 DnBP for 30, 60 and 90 days each, and the effects on survival, body growth, whole‐body concentrations of sex steroid hormones and gonadal development were investigated. The lowest observed effective concentration to affect the condition factor after 90 days was 5 µg l^?1. Complete feminization of the gonad was noted in fish exposed to 5 µg l^?1 for 90 days and to 15 and 50 µg l^?1 of DnBP for 30 or 60 days. After 90 days of exposure to DnBP, the ovaries were regressed and immature as opposed to the control fish which were in early‐vitellogenic stage. Testes, present only in fish exposed to 5 µg l^?1 of DnBP for 30 or 60 days, were immature in comparison to the control fish that contained testes in the mid‐spermatogenic phase. The E2/11‐KT ratio was significantly higher only after exposures to 5 µg l^?1 DnBP for 90 days and 50 µg l^?1 DnBP for 30 days. Our data suggest that exposures to 5 µg l^?1 DnBP for 30 days did not have profound effects on body growth and gonadal differentiation of fish. However, 30 days of exposure to 15 µg l^?1 could interfere with the gonad development and to 50 µg l^?1 could compromise the hormonal profile of juvenile fish. Copyright © 2014 John Wiley & Sons, Ltd.     

Oxidative stress as a mechanism for toxicity of 2,4-dichlorophenoxyacetic acid (2,4-D): studies with goldfish gills

The effects of exposure to the widely used herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D), at environmentally permitted (1 mg L^?1), slightly toxic (10 mg L^?1), and highly toxic (100 mg L^?1) concentrations were analyzed in gills of goldfish, Carassius auratus, a popular fish model for ecotoxicological research. Fish were exposed to the pesticide in water for 96 h and an additional group of fish were treated by the highest 2,4-D concentration and then allowed to recover for further 96 h. Among markers of oxidative stress, goldfish exposure to 2,4-D did not affect carbonyl protein levels in the gills, but fish exposure to 100 mg L^?1 of 2,4-D enhanced lipid peroxide concentrations (by 58 %) and oxidized glutathione levels (by 49 %), the latter also significantly increasing (by 33 %) oxidized/total glutathione ratio. Activities of three enzymes of antioxidant defence also increased under 2,4-D exposure: superoxide dismutase (by 29–35 %), catalase (by 41 %), and glutathione peroxidase (by 19–33 %). Activities of other antioxidant associated enzymes as well as other potential markers of stress (e.g. aminotransferase enzymes, acetylcholinesterase, lactate metabolism) showed little or no response in gills to 2,4-D exposure. However, virtually all affected parameters returned to control values during recovery period. A combination of selected indices of oxidative stress and antioxidant defence, measured in fish gills, may provide to be effective biomarkers to assess environmental hazards of 2,4-D to freshwater ecosystems.     

Effect of nitrite exposure on hematological parameters and blood respiratory properties in the sea bass Lates calcarifer

Changes in hematological parameters and blood respiratory properties of Lates calcarifer in response to nitrite exposure were studied. Exposure to 10 mg · L^?1 NO₂-N for 8 days resulted in significant increases in blood nitrite and methemoglobin contents. Total hemoglobin was reduced resulting in an overall decline in functional hemoglobin. There was no significant change in hematocrit and red blood cell count. In another set of experiments, hematological parameters and venous blood oxygen tension of L. calcarifer after exposure to 15, 20, 30, 50, and 80 mg · L^?1 NO₂-N for 4 days were determined. Blood nitrite and methemoglobin content increased proportionally to the increase in ambient nitrite concentration. The methemoglobin content (as percent of total hemoglobin) of fish immersed in a nitrite concentration equivalent to the 96 h LC₅₀ (93 mg · L^?1 NO₂-N) was estimated to be 83%. Venous blood oxygen tension tended to decrease as nitrite concentration increased. In a third set of experiments, sea bass were exposed to 50 mg · L^?1 NO₂-N for 4 days. Exposure to nitrite resulted in lowered arterial and venous blood oxygen tensions, arterial and venous oxygen content, and blood oxygen capacity. However, no change in venous blood pH was observed between control and nitrite-treated fish. The blood of Lates has a relatively low oxygen affinity (P₅₀ = 14.5 ± 2.3 mm Hg) with a Hill coefficient (n) of 1.46. Exposure of fish to 50 mg · L^?1 NO₂-N resulted in a leftward and upward shift of the blood oxygen dissociation curve (P₅₀ = 5.9 ± 1.6 mm Hg; n = 0.99). The increased blood oxygen affinity in nitrite-treated fish probably facilitated oxygen loading from water to the blood stream at the respiratory surfaces so as to compensate for the decline in oxygen carrying capacity. © by John Wiley & Sons, Inc.     

Facilitation by alcohol of active avoidance acquisition performance in the goldfish

Common goldfish (Carassius auratus) were exposed for 3 hr or 6 hr to alcohol solution (628 mg per 100 ml) or were treated identically but never exposed to alcohol. Following pretraining exposure, fish were given 20 trials of active dark-avoidance training in individual shuttle boxes. Alcohol-treated fish obtained significantly higher mean levels of correct responding during acquisition. The enhancement of acquisition performance was not appreciably altered by 6-hr compared with 3-hr pretraining exposure. Neither was the enhanced acquisition performance attributable to increased general shuttling during the 10-sec shock-free conditioned stimulus period. There was some evidence that alcohol-treated fish, compared with controls, swam into and out of the electrified compartment more often during training; however, this sort of responding correlated with correct responding no better for alcohol-treated than for control fish. In another experiment, alcohol was shown to increase sensitivity to light in goldfish. The explanation of the observed facilitation by alcohol of acquisition performance in goldfish may involve an effect on stress or anxiety; an effect of increased sensitivity to electric shock; or an effect of acute increased availability of central monoamines.     

The effects of pulp and paper mill effluent on physiological and hematological endpoints in fingerling largemouth bass (Micropterus salmoides)

The purpose of this study was to evaluate the effects of bleached kraft mill effluent on selected physiological and hematological endpoints in fingerling largemouth bass (Micropterus salmoides). Fish were exposed for 35 days to surface water collected at sites up- and downstream from a pulp and paper mill treatment-effluent discharge. The condition factor, spleen somatic index, and pronephros cellularity were statistically significantly decreased in fish exposed to the downstream site, compared to the upstream site. There was also a shift from lymphocytes to neutrophils in peripheral blood of fish exposed to the downstream site. Hematocrit values and the liver somatic index were statistically significantly increased in fish in the downstream exposure. These results indicate that in-stream exposure to elemental-chlorine-free pulp and paper mill effluents produce a generalized stress response, leading to potential immunosuppression in fish.     

Diurnal activity patterns as a sensitive behavioural outcome in fish: effect of short‐term exposure to treated sewage and a sub‐lethal PPCP mixture

Sub‐lethal toxicological responses are common occurrences in aquatic animals exposed to sewage wastewater and organic wastewater contaminants. Behavioural alterations are particularly sensitive indicators of sub‐lethal toxicological stress in animals exposed to various pollutants, and often correlate with higher‐level outcomes. Diurnal activity patterns in many fish species are sensitive to changes in natural biotic factors, but few studies have explored how environmental pollutants influence such rhythms. We investigated diurnal activity patterns in the mosquitofish (Gambusia holbrooki), after exposure to UV‐treated sewage and a mixture of key contaminants identified through chemical analysis and subsequent risk‐based prioritization of the wastewater. Exposure to 50% and 100% wastewater abolished daytime activity levels in male, but not female fish. Chemical analysis identified fluoxetine, diazinon and triclosan above their reported predicted‐no‐effect‐concentrations (PNECs), and fish were thus exposed to a mixture of these compounds at 1, 10 and 100 μg l^–1. Behavioural responses were highly consistent between fish exposed to wastewater and the contaminant mixture, indicating that these prioritized contaminants are indeed likely contributing to the observed effects. Effective concentrations of the mixture were considerably lower than those reported as eliciting behavioural effects in previous studies exploring each of these compounds alone. Results warn of the potential for negative higher‐level consequences associated with exposures of fish to common organic wastewater contaminants, as altered diurnal activity patterns could conceivably scale‐up to influence performance including foraging success and predator avoidance. Further research is necessary to increase our understanding of linkages between alterations to diurnal activities and effects at the population level. Copyright © 2016 John Wiley & Sons, Ltd.     

Assessment of the impact of a bleached kraft mill effluent on a south‐central USA river

We initiated a multifaceted, integrated investigation of the general health of the aquatic environment near a bleached kraft pulp and paper mill. This southcentral U.S. mill discharges about 125,000 cubic meters of treated effluent per day into an adjacent river. The sampling sites for this study were 1.8 km upstream from the mill's discharge, 0.25 km below the mill's outlet, and 5 km downstream from the discharge area. No toxicity was observed using Ceriodaphnia dubia and Pimephales promelas in aqueous phase tests or with Hyalella azteca and Chironomus tentans in sediment phase tests. Field examinations of two small fish species and sediment macroinvertebrate communities from each sampling site revealed no significant adverse effects. Bluegill sunfish (Lepomis macrochirus) were exposed for 35 days to site sediments and were evaluated for ethoxyresorufin O‐dethylase (EROD) activity, cytochrome P4501A (CYP1A) content, DNA strand breaks, condition index, organ indices, gross pathology, and immune responses. No significant adverse effects were observed in sediments immediately below the mill's effluent outlet, though detoxification enzyme activity was elevated in liver tissue of bluegill sunfish exposed to site 3 sediment. Embryos of mosquitofish (Gambusia affinis) were evaluated for developmental and reproductive abnormalities following a static laboratory exposure of gravid females to sediments from the three study sites for 56 days. The embryos showed no significant effects on a suite of reproductive parameters among the three sites. We concluded that there was no significant evidence of adverse impacts on the receiving river or its biota attributable to treated bleached kraft mill effluent based on a comprehensive suite of bioindicators of exposure and effects. ©2000 John Wiley & Sons, Inc. Environ Toxicol 15: 28–39, 2000     

Reproductive and stress hormone levels in goldfish (Carassius auratus) exposed to oil sands process-affected water

Athabasca oil sands mining in northern Alberta produces process-affected waters that are characterized by the presence of naphthenic acids, polycyclic aromatic hydrocarbons, and high salinity. The purpose of this study was to examine the impact of these process-affected waters on reproductive and stress related endpoints in mature goldfish, Carassius auratus. In two separate studies, testosterone and 17beta-estradiol levels in the plasma were significantly reduced in both male and female goldfish caged for 19 days in process-affected waters relative to controls. This effect was most pronounced in goldfish caged at a site containing mature fine tailing and tailings pond water (P5). Ovarian and testicular tissues from fish in the caging studies were incubated in vitro to evaluate potential differences in basal steroid production levels and responsiveness to human chorionic gonadotropin (hCG). Basal levels of testosterone were reduced significantly in males and females from P5 compared with the control pond (P1) demonstrating that the gonads from exposed fish had a diminished steroidogenic capacity. Gonadal tissues of fish from all ponds responded similarly to hCG suggesting that the steroid biosynthetic pathway remained functionally intact. Plasma cortisol levels were significantly higher in male goldfish caged in a pond containing mature fine tailings and capped with uncontaminated water (P3) and in P5 compared with P1. Collectively, these studies suggest that waste products of oil sands mining have the potential to disrupt the normal endocrine functioning in exposed fish through alterations to both reproductive and glucocorticoid hormone biosynthesis. In additional laboratory studies, exposure of goldfish to a naphthenic acid extract for 7 days failed to replicate the effects of processes-affected waters on plasma steroid levels and the causative agent(s) responsible for the effects on steroid biosynthesis remains to be identified.     

Embryonic and developmental toxicity of the ionic liquid 1‐methyl‐3‐octylimidazolium bromide on goldfish

The embryonic developmental toxicity of the ionic liquid (IL) 1‐methyl‐3‐octylimidazolium bromide ([C₈mim]Br) on the goldfish Carassius auratus was evaluated in this study. First, the 72 h 50% lethal concentrations (72 h‐LC₅₀) for [C₈mim]Br in goldfish embryos at the stages of cleavage, early gastrula, closure of blastopore, and heart beating were determined by preliminary acute toxicity tests. After that, fish embryos in different developmental stages (cleavage, early gastrula, closure of blastopore, and heart beating) were exposed to 10.4, 20.8, 41.6, and 104 mg/L of [C₈mim]Br until their hatching stage. The results of the acute toxicity tests showed that 72 h‐LC₅₀ values at the early cleavage, early gastrula, closure of blastopore, and heart beating stages of development were 208.96, 187.1, 245.03, and 298.33 mg/L, respectively. In the subchronic tests, [C₈mim]Br exposure prolonged the duration of embryo dechorionation and decreased the hatching rates of the treated embryos compared to control embryos. In addition, [C₈mim]Br treatment also caused remarkable increases of embryonic malformation and mortality ratio in most treatment groups. Finally, we also found that the embryonic and developmental toxicity of [C₈mim]Br on fish embryos was dose‐response and developmental stage‐specific. These results indicate that [C₈mim]Br has toxic effects on the early embryonic development of goldfish, and the risk to aquatic ecosystem by ILs leaking into the water body must be evaluated in the future. © 2009 Wiley Periodicals, Inc. Environ Toxicol, 2010.     

Assessment of biochemical,hematological and behavioral biomarkers of Cyprinus carpio on exposure to a type-II pyrethroid insecticide Alpha-cypermethrin

This study assessed some important physiological biomarkers of freshwater edible fish Cyprinus carpio following exposure to 10 % (T1) and 20 % (T2) sublethal concentrations of Alpha-cypermethrin (A-cyp) over a total period of 45 days. Behavioral responses were noticed and Kaplan-Meier survival curves were prepared during acute toxicity study. Total serum protein concentration, total erythrocyte count, hemoglobin, packed cell volume, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and total leukocytes count were decreased significantly (p < 0.05), while the blood glucose, total serum lipid concentration, and clotting time were increased significantly (p < 0.05) over control. The most affected fish group and most significantly altered biomarker under toxic stress of A-cyp were identified using integrated biomarker response (IBR). The biomarker response index (BRI) values measured the overall health status of the treated fish and indicated that moderate adverse effects were exerted on the fish group exposed to T2 for 45 days.     

Effects of ECF-Kraft pulp mill effluent treated with fungi (Rhizopus oryzae) on reproductive steroids and liver CYP1A of exposed goldfish (Carassius auratus)

The toxicity of bleached Kraft pulp mill effluents (BKME) is usually attributed to chemical compounds which are produced and released throughout various stages of pulp and paper production. The main objective of the present work was to detect sub-lethal responses of goldfish (Carassius auratus) to secondary treated BKME which was treated with Rhizopus oryzae. A total of 96 carps (C. auratus; 11 ± 3 g) were exposed to different concentrations of the post-treated effluent (0, 1, 10, 25, 50, and 100%), in 28 days semi-static tests. Several biomarkers were then evaluated to assess the toxicological effects: induction of CYP1A (metabolic processes of organic compounds in liver), change in steroid profiles (11-Ketotestosterone, 17β-estradiol), histopathology of liver and gonads and somatic indices (GSI, HSI) for endocrine disruption and other physiological disturbances. The most significant results show an induction of CYP1A in both sexes and a decrease of 17β-estradiol concentrations in females. Histopathological changes such as liver tissue degeneration were observed in fish exposed to 50 and 100% of the BKME. Although the BKME was biologically treated there are some chemical compounds in the effluent that are capable to affect fish physiology, however, a clear evidence for endocrine disruption was not found.     

A preliminary investigation into the use of biomarkers for the monitoring of an ocean outfall

The use of several biomarkers of exposure for monitoring a treated mixed effluent from the Latrobe Valley Ocean Outfall was examined. Sand flatheads (Platycephalus bassensis) were exposed in the laboratory to two dilutions of effluent (1.3 and 2.5%, v/v) for three days. Cytochrome P450 content, 7-ethoxyresorufin-O-deethylase (EROD) activity, and biliary metabolites of polycyclic aromatic hydrocarbons (PAH), 2-chlorosyringaldehyde and 2,6-dichlorosyringaldehyde, were measured. There were no statistically significant differences in cytochrome P450 content or EROD activity between control and exposed fish. Analysis of the bile by gas chromatography/mass spectrometry of fish exposed to 2.5% effluent found no increases above background in the levels of PAHs, or specific chlorinated phenolics that are found in bleached hardwood pulp effluents. © 1996 by John Wiley & Sons, Inc.     

蒿甲醚治疗动物血吸虫病的实验研究

蒿甲醚混悬液总量120～800 mg/kg,分1～4天给,灌胃治疗病鼠和病免,减虫率为55.3%～88.5%;总量25～35 mg/kg,分3天给治疗病犬,减虫率为52.6%～59.1%。蒿甲醚油剂以225～435 mg/kg,分3天给,皮下注射治疗病鼠,减虫率为70.5%～81.2%;总量200～400mg/kg和150～250 mg/kg,分4～5天给分别肌注治疗病兔和病犬,减虫率分别为85.9%～90.7%和91.3%～99.3%。犬每天肌注油剂30～90 mg/kg,连注5天,出现较明显的胃肠道刺激症壮,组织学检查出现胃肠道、肝、肾等组织的可逆性病理损害。