The interaction of treated bleached kraft mill effluent and dissolved oxygen concentration on the survival of the developmental stages of the sheepshead minnow (Cyprinodon variegatus)

The interactions of treated bleached kraft mill effluent (BKME) and dissolved oxygen concentration (DO) on the survival of the embryo, fry, juvenile and adult stages of the sheepshead minnow, Cyprinodon variegatus, were studied under continuous-flow 96 h bioassay conditions. Embryo survival was dependent on effluent concentration only and showed no interaction at nominal DO concentrations of 1.0, 3.0 and 5.0 mg l⁻¹. Survival of the fry was related solely to DO concentration with no interaction with BKME concentrations up to 100%. Juvenile sheepshead minnows showed increased sensitivity to BKME at a nominal DO concentration of 1.0 mg l⁻¹. Adult fish were not affected by BKME at any of the DO concentrations tested. This study shows that the acute toxicity of BKME effluent to sheepshead minnows is a function of the developmental stage of the organism and DO concentration in the receiving stream.     

An evaluation of the potential toxicity of treated bleached kraft mill effluent to striped bass (Morone saxatilis walbaum) larvae exposed through metamorphosis to the juvenile stage

Twenty-day-old striped bass (Morone saxatilis) larvae were exposed to a range of treated bleached kraft mill effluent (BKME) concentrations from 0 to 20% effluent by volume (v/v) under continuous flow test conditins. The experimental test concentrations in the 2–20% BKME test aquaria had a BOD₅ which ranged from < 1 to 5 mg l⁻¹, TSS 12–17 mg l⁻¹, and true color 35–416 mg l⁻¹. Bleached kraft mill effluent did not kill larvae exposed to it for 20 days through metamorphosis to the juvenile stage. The BKME did not alter growth in length, weight or condition factor in larvae over the 20-day exposure period as determined by multiple regression analysis. A linear regression analysis on the dry weight data at Day 20 only, however, indicated a trend of decreasing weight with increasing BKME concentration. Effluent-exposed larvae also developed normally during the 20-day study. All individuals examined completed the transformation from postlarvae to juveniles by the age of 40 days.     

Effects of lignin and chlorolignin in pulp mill effluents on the binding and bioavailability of hydrophobic organic pollutants

The partition coefficients (K_p) of benzo(a)pyrene (BaP), 3,3′,4,4′-tetrachlorobiphenyl (TCB) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to dissolved kraft lignin (Indulin AT), chlorolignin isolated from a bleached kraft mill effluent (BKME) and dissolved organic matter (DOM) in a lake receiving BKME were measured by equilibrium dialysis. The K_p values of kraft lignin were 28.2 × 10⁵, 6.5 × 10⁵ and 15.9 × 10⁵ and those of chlorolignin were 8.3 × 10⁵, 2.9 × 10⁵ and 2.2 × 10⁵ for BaP, TCB and TCDD, respectively. In addition, DOM in a series of lake water samples collected from the southern part of Lake Saimaa, SE Finland, receiving BKME revealed higher binding capacities to all of the three model compounds than natural DOM in water upstream from the pulp mill. An important phenomenon related to the environmental transport and fate of xenobiotics was almost the full reversibility of the binding between chlorolignin and model compounds. The obtained K_p values of chlorolignin after a 4 day dissociation period were 12.6 × 10⁵ and 4.6 × 10⁵ for BaP and TCDD, respectively.In short-term (24 h) accumulation experiments with Daphnia magna the effects of kraft lignin and chlorolignin on the bioavailability of three model compounds was very clear. The bioconcentration factors of the xenobiotics in the chlorolignin containing water (DOC = 10 mg C/l) were 20–30 and 25–35% of those organic-free control and upstream reference waters (DOC = 7.2 mg C/l), respectively. The effect of chlorolignin of BKME on the bioavailability of model compounds was also seen in the lake water series of Lake Saimaa.     

Toxicity of sodium nitrilotriacetate (NTA) to the fathead minnow and an amphipod in soft water

Amphipods, Gammarus pseudolimnaeus Bousfield and fathead minnows, Pimephales promelas Rafinesque, were submitted to acute (96-h) and chronic (generation-cycle) bioassays with sodium nitrilotriacetic acid (NTA). All measurements are reported as Na₃NTA. The average 96-h TL50 values under flow-through conditions were 98 mg 1⁻¹NTA for the amphipod and 114 mg 1⁻¹ for the fathead minnow. The acute toxicity of NTA was caused in part by the high pH resulting from the addition of large amounts of NTA (> 100 mg 1⁻¹) to soft water. Controlling pH reduced the lethality of NTA by at least one-half to fathead minnow larvae. The chronic no-effect level of NTA to the amphipods was 19 mg 1⁻¹; in fathead minnows, it exceeded the highest exposure level (> 54 mg 1⁻¹).     

Lethal and sublethal toxicity of ammonia to native, invasive, and parasitised freshwater amphipods

In lethal and sublethal ammonia toxicity tests, we examined differences in tolerance of three species of freshwater amphipods, one native and two invasive in Ireland. The native Gammarus duebeni celticus was slightly less tolerant to ammonia than the invasive G. pulex (96 h LC50= 1.155 and 1.544 mg l(-1), respectively), while another invader, Crangonyx pseudogracilis, had the lowest tolerance (LC50= 0.36 mg l(-1)). Parasitism of G. pulex by the acanthocephalan Echinorhynchus truttae greatly reduced the tolerance of the invader to ammonia (LC50= 0.381 mg l(-1)). Further, precopula pair disruption tests indicated that G. d. celticus was more sensitive to ammonia than G. pulex at sublethal levels. We discuss these results in the context of the ecological replacements of native by invader amphipods.     

Bioaccumulation of As, Cd, Cr, Hg(II), and MeHg in killifish (Fundulus heteroclitus) from amphipod and worm prey

Elevated metal levels in fish are a concern for the fish themselves, their predators, and possibly humans who consume contaminated seafood. Metal bioaccumulation models often rely on assimilation efficiencies (AEs) of ingested metals and loss rate constants after dietary exposure (k_efs). These models can be used to better understand processes regulating metal accumulation and can be used to make site-specific predictions of metal concentrations in animal tissues. Fish often consume a varied diet, and prey choice can influence these two parameters. We investigated the trophic transfer of As, Cd, Cr, Hg(II), and methylmercury (MeHg) from a benthic amphipod (Leptocheirus plumulosus) and an oligochaete (Lumbriculus variegatus) to killifish (Fundulus heteroclitus) using gamma-emitting radioisotopes. Except for MeHg, AEs varied between prey type. AEs were highest for MeHg (92%) and lowest for Cd (2.9-4.5%) and Cr (0.2-4%). Hg(II) showed the largest AE difference between prey type (14% amphipods, 24% worms). For Cd and Hg(II) k_efs were higher after consuming amphipods than consuming worms. Tissue distribution data shows that Cd and Hg(II) were mainly associated with the intestine, whereas As and MeHg were transported throughout the body. Calculated trophic transfer factors (TTFs) suggest that MeHg is likely to biomagnify at this trophic step at all ingestion rates, whereas As, Cd, Cr, and Hg(II) will not. Data collected in this study and others indicate that using one prey item to calculate AE and k_ef could lead to an over- or underestimation of these parameters.     

Toxic effects of aliphatic chlorinated by-products from vinyl chloride production on marine animals

The acute toxic effects of chlorinated aliphatic hydrocarbons, formed as by-products from one Swedish and one Norwegian plastic production factory, were examined by experiments with cod (Gadus morhua), shrimp (Crangon crangon) and a polychaete (Ophyryotrocha labronica). The toxicity of 1,2-dichloroethane—a dominating compound of the by-products—and a distillate with heavier compounds were also estimated. The toxicity (48 h, LC50) ratio between the concentrations of a Swedish by-product, a Norwegian by-product, and dichloroethane was 1:9:34. The effects of 1,2-dichloroethane, 1,1,2-trichloroethane and 1,1,2-trichloroethene on the reproductivity, and on the survival of adults of Ophryotrocha were studied. The reproductivity was affected by these components in far lower concentrations than those having acute toxic effects on adult specimens. In one experiment series Ophryotrocha was exposed suddenly to the test solutions and in a second series the first presentation was made by a successive increase of the concentration during one hour. The estimated 96-h LC50-values for the test with successive increase were 1·8–3·1 times higher than those found for the test with sudden exposure. It is suggested that a physiological shock in the start of bioassay experiments might have reduced the LC50-values in many previous tests.     

Toxicity, uptake and survey studies of boron in the marine environment

Little is known about the toxic and bioaccumulative dangers to aquatic life posed by borate discharge recently initiated by coastal British Columbia groundwood pulp mills. Bioassays with sodium metaborate and underyearling coho salmon (Onchorhynchus kisutch) in fresh water yielded a 283-h lc₅₀ of 113 μg ml⁻¹ (104, 123 = 95% confidence limits). Toxicity to underyearling coho in sea water appeared considerably greater with a 283 h lc₅₀ of 12.2 μg ml⁻¹ (10.89, 14.56 = 95% confidence limits). The disparity between fresh and saltwater boron toxicity to coho is not understood at this time. In salmonids, boron enters the tissues slowly, necessitating prolonged bioassay tests. Sockeye salmon (O. nerka) and juvenile oysters (Crassostrea gigas) exposed to sublethal doses of boron take up boron roughly in relation to its availability. Oysters show no bioaccumulative potential or prolonged retention of boron following cessation of dosage. Field surveys conducted before and after industrial borate emission confirm the lack of evidence for tissue bioaccumulation. Results of a survey of boron levels in receiving waters are reported. No hazard to salmonids of oysters at the present level of industrial discharge of boron (≤1 μg B ml⁻¹) is apparent from this work.     

Improve effluent water quality at Abu‐Rawash wastewater treatment plant with the application of coagulants

This research investigated a process to improve the Abu‐Rawash WWTP effluent water quality with the application of aluminum chloride (AlCl₃); in turn, this improvement will lead to improve water quality at the El‐Rahawy drain and in the Rosetta branch of the Nile River. Sewage samples were collected from the effluent of the grit removal chamber. Jar tests were performed to estimate the coagulant dosage required to obtain acceptable treatment. To prove the efficiency of the AlCl₃ in wastewater treatment, a comparison was conducted between AlCl₃ and other common coagulants used in wastewater treatment which include ferrous sulfate (FeSO₄), ferric sulfate (Fe₂(SO₄)₃) and ferric chloride (FeCl₃). Results showed AlCl₃ was more cost‐effective and efficient in wastewater treatment than these three iron‐based coagulants. A paired‐sample t‐test was also performed to rank the performance of the various coagulants tested. The t‐test has also confirmed that the AlCl₃ has the highest performance over those coagulants.     

Effect of pH on toxicity of kraft pulp and paper mill effluent to salmonid fish in fresh and seawater

In freshwater bioassays with juvenile rainbow trout (Salmo gairdneri), at initial pH values from 4 to 11, kraft mill effluents were considerably less toxic at pH 9–10 than at neutrality. When pH of test solutions was controlled throughout the bioassay period, the least toxic range was 8.5–9.5. Toxicity at typical receiving-water pH values was 50–67% greater.The acute toxicity of effluent samples to yearling coho salmon (Oncorhynchus kisutch) was identical for these effluents in seawater and freshwater respectively, provided that the pH was adjusted and held at the same value, and that test fish were previously acclimated to the dilution water for several months. Thus seawater constituents other than pH did not affect the acute toxicity of pulp and paper mill effluents appreciably.     

Acute toxicity of unbleached kraft mill effluent (UKME) to the opossum shrimp, Neomysis americana smith

Ninety-six hour TL₅₀ values of unbleached kraft mill effluent (UKME) for Neomysis americana were found to range from concentrations of 3.29–6.85 per cent at 26–28°C and 3.90–7.30 per cent at 16–18°C. Differences between batches of effluent proved insignificant in experiments at each temperature regime. Furthermore, UKME did not lose its toxicity when stored for 5–7 days at 4°C. A concentration of 20 per cent effluent killed 100 per cent of the organisms in 8 of the 12 bioassays. Slope functions and confidence limits of TL₅₀ were calculated. Toxicity did not appear to be correlated with the Biochemical Oxygen Demand (BOD) of individual batches of raw effluent.     

Modeling residential indoor concentrations of PM2.5, NO2, NOx,and secondhand smoke in the Subpopulations and Intermediate Outcome Measures in COPD (SPIROMICS) Air study

Increased outdoor concentrations of fine particulate matter (PM_2.5) and oxides of nitrogen (NO₂, NO_x) are associated with respiratory and cardiovascular morbidity in adults and children. However, people spend most of their time indoors and this is particularly true for individuals with chronic obstructive pulmonary disease (COPD). Both outdoor and indoor air pollution may accelerate lung function loss in individuals with COPD, but it is not feasible to measure indoor pollutant concentrations in all participants in large cohort studies. We aimed to understand indoor exposures in a cohort of adults (SPIROMICS Air, the SubPopulations and Intermediate Outcome Measures in COPD Study of Air pollution). We developed models for the entire cohort based on monitoring in a subset of homes, to predict mean 2-week–measured concentrations of PM_2.5, NO₂, NO_x, and nicotine, using home and behavioral questionnaire responses available in the full cohort. Models incorporating socioeconomic, meteorological, behavioral, and residential information together explained about 60% of the variation in indoor concentration of each pollutant. Cross-validated R² for best indoor prediction models ranged from 0.43 (NO_x) to 0.51 (NO₂). Models based on questionnaire responses and estimated outdoor concentrations successfully explained most variation in indoor PM_2.5, NO₂, NO_x, and nicotine concentrations.     

The toxicity of various mining flotation reagents to rainbow trout (Salmo gairdneri)

Preliminary testing of eight collectors (xanthates) and four frothers in 96-h static and 28-day flow-through bioassays using rainbow trout as the test organism show a great disparity in the toxicity of the chemicals administered in these two ways.For the short-term tests, the relative toxicity of the compounds is expressed as an lc₅₀ or as a range of concentration in mg l⁻¹ in which the lc₅₀ is expected to fall. Of the collectors tested in this way sodium ethyl and potassium amyl xanthate were the most toxic, with lc₅₀'s in the range of 30–50 mg l⁻¹. Among the frothers, xylenol (cresylic acid) was found to be the most toxic (5.6 mg l⁻¹ >lc₅₀ > 3.2 mg l⁻¹) while polypropylene glycol was least toxic (lc₅₀ > 1000 mg l⁻¹).The long-term tests using potassium ethyl, sodium isopropyl, sodium ethyl, and potassium amyl xanthate indicated that in the flow-through system, the toxicity of the chemicals was in the order of 100 fold greater compared with the static bioassay results.     

Comparative toxicity of ten organic chemicals to ten common aquatic species

The susceptibilities of 10 aquatic organisms to 10 organic chemicals were determined using lethality tests. The species included six fishes, two crustaceans, a chironomid and an amphibian. The chemicals were selected to span the toxicity range from 26 g l⁻¹ to 1 μg l⁻¹ and include chemicals which were lethal by four modes of toxic action. There was no consistent relative susceptibility among the test species because the sensitivity to specific modes of toxic action varied among the chemicals. Nonetheless, the toxicities of the chemicals to any given species were highly correlated to the toxicities to other species, particularly among fishes. The 96-h median lethal concentration (LC₅₀) of the chemicals to rainbow trout (Salmo gairdneri) could be estimated from the 96-h LC₅₀ with fathead minnows (Pimephales promelas) with a correlation coefficient greater than 0.99. Equations for estimating the lethal concentration of chemicals with each species from the 96-h LC₅₀ for fathead minnows are presented.     

Long-term effects of treated domestic wastewater on brown trout

A 12-month bioassay was conducted to determine the effects of unchlorinated, treated, domestic wastewater on survival, growth, swimming performance, and gill tissue of brown trout (Salmo trutta). Ammonia was the toxicant of concern, because the facility's effluent periodically exceeded the U.S. Environmental Protection Agency's (EPA) recommended criterion. Juvenile brown trout (initial weight = 2 g), which were exposed to six concentrations (0–37%) of effluent, were fed a restricted ration, so that growth rates were similar to those of wild stream residents. At the highest effluent concentration, monthly mean concentrations of un-ionized ammonia ranged from 0.004 to 0.055 mg l⁻¹ NH₃---N (at. wt = 14); these concentrations exceeded the EPA criterion of 0.016 mg l⁻¹ about 40% of the time. There were no significant effects of effluent concentration on survival, growth, or swimming performance of brown trout, but the degree of damage to gills was directly related to effluent concentration.     

An assessment of estrogenic organic contaminants in Canadian wastewaters

A suite of 30 primarily estrogenic organic wastewater contaminants was measured in several influent/effluent wastewater samples from four municipal wastewater treatment plants and effluents from one bleached kraft pulp mill (BKME) using an ultra-trace analytical method based on gas chromatography-high resolution mass spectroscopy (GC-HRMS). In vitro recombinant yeast assay detection of the estrogenic equivalent (EEq) on whole and solid phase extracted (SPE) and fractionated wastewater was also performed. 19-norethindrone was the most frequently detected and abundant (26-224 ng/L) of all the synthetic estrogens/progesterones in the influent samples. 17alpha-ethinylestradiol was the more frequently detected synthetic estrogen/progesterone in the effluents occurring at or below 5 ng/L with some sporadic occurrences of up to 178 ng/L. The greatest levels of steroidal estrogens in municipal effluents were E1>E2>E3 which were all <20 ng/L. Nonylphenol and di(2-ethylhexyl) phthalate were found to be the highest non-steroidal synthetic compounds surveyed in both municipal influent and effluent samples, both occurring at 6-7 microg/L in municipal effluents. BKME contained relatively large amounts of the plant sterol stigmasterol (4 microg/L) but low amounts of fecal sterols, and steroidal estrogens (E2 only at 6 ng/L) when compared to the municipal effluents. In vitro EEq in the wastewater surveyed ranged from 9-106 ng E2/L and ranked from municipal influent>municipal effluent approximately BKME, with most of the estrogenicity fractionating in the 100% methanol SPE fraction followed by a secondary amount in the diethyl ether (for municipal) or methyl-tert butyl ether (for BKME) SPE fractions. Most correlations between chemical and in vitro estrogenic equivalency were weak (p>0.05 in most cases). Unexpected inverse correlations between in vitro estrogenic activity and concentrations of the estrogenic contaminant bisphenol A were found which likely contributed to the weakness of these correlations. A modified toxicity identification and evaluation procedure was continued with the SPE extracts from the more potent 100% methanol SPE fractions of municipal effluent. High performance liquid chromatography band elution retention times, based on in vitro estrogen detection, indicated that steroidal estrogens such as E2 were responsible for most of the estrogenicity of the samples. Subsequent collection and GC-MS analysis of active bands did not confirm the presence of steroidal estrogens, but expanded the possibility of phthalate esters (i.e. dibutyl phthalate) and natural sterols (i.e. beta-sitosterol) contributing to the overall estrogenic load.     

Avoidance of bleached kraft mill effluent by pre-exposed Coregonus albula L.

The ability of vendace (Coregonus albula L.) to avoid different concentrations of bleached kraft mill effluent (BKME) was studied in the laboratory with fish pre-exposed to BKME for 1 week and non-pre-exposed fish. Pre-exposure to BKME in sublethal concentrations reduced the avoidance of BKME by vendace. Throughout the range of exposure concentrations (0.13–4.50 v/v%), pre-exposed fish tended to be observed less in the clean water than non-pre-exposed fish or even to prefer contaminated water. In field conditions, changes in behaviour might lead to a chain reaction: the fish come into contact with concentrations of BKME lower than the threshold level for avoidance and their threshold level increases gradually due to this exposure, which makes exposure to higher concentrations possible and weakens the ability to return to clean water. Desensitization caused by pre-exposure and long distances between pronounced BKME concentration differences in the field together makes it improbable that the vendace can show avoidance responses in the field. Analyses of the various waste-water samples support the conclusion that the most toxic components in BKME, resin acids and chlorophenols, are of minor importance to the avoidance reaction.     

The risks from airborne asbestos in the urban environment

The objective of this full‐scale study is to determine the treatment performance of the activated sludge process for treating low strength municipal wastewater. The plant is located in Painesville, Ohio, and discharges its treated effluent into Grand River. The average plant wastewater flow was 3.43 MGD (million gallons per day). The plant performance was evaluated for a 12‐month period in 1989. The low strength municipal wastewater contained 104 mg/L TSS (total suspended solids), 105 mg/L BOD (biochemical oxygen demand), 17.76 mg/L TKN (total kjeldahl nitrogen), 9.66 mg/L NH₃‐N, and 3.90 mg/L P (phosphorus). The treatment performance after various degrees of treatment is as follows: primary treatment: 30% BOD and 54% TSS removal, secondary treatment: 97% BOD and 87% TSS removal, and tertiary treatment: 98% BOD and 98% TSS removal. The primary effluent contained 73 mg/L BOD and 48 mg/L TSS; the secondary effluent contained 3 mg/L BOD and 13 mg/L TSS; and the final effluent contained 2 mg/L BOD and 2 mg/L TSS. The effluent contained 0.22 mg/L NH₃‐N and 0.49 mg/L P, which were far below the US EPA standard of 10 mg/L BOD, 10 mg/L TSS, 1 mg/L NH₃‐N, and 1 mg/L P.     

Hepatic metallothionein level and mixed function oxidase activity in fingerling rainbow trout (Oncorhynchus mykiss) after acute exposure to pulp and paper mill effluents

Hepatic metallothionein (MT) levels and mixed function oxidase (MFO) activity (7-ethoxyresorufin-o-deethylase or EROD) were measured in fingerling rainbow trout (Oncorhynchus mykiss) exposed to sublethal concentrations of 12 pulp and paper effluents, after completion of 96 h static acute lethality assays. Barring one primary-treated effluent where MFO levels were significantly depressed and two secondary-treated effluents where no significant MFO induction were observed, all other effluents triggered significant induction of MT and EROD, regardless of mill process/treatment or of effluent lethality and chemical characteristics. MT and EROD inductions were significant, however, at higher concentrations for secondary-treated effluents than for primary-treated ones. Lethal (96 h LC₅₀s) to sublethal (MT and EROD lowest observable effect concentrations) ratios were variable and indicated that significant biochemical effects were present at effluent concentrations that were roughly 4–33 (MT) and 3–59 (EROD) times lower than the LC₃₀. Enzyme induction ranged from 1.3 to 2.5-fold for MT and from 1.3 to 9.4-fold for EROD compared to controls. Limited chemical data available suggest that there were indeed classes of compounds present capable of inducing MT or EROD. Observed patterns of MT/MFO responses also suggest that contaminant interactions may have interfered with induction for some of the effluents studied. Refinements of this combined (sub)lethal bioassay procedure are envisaged to determine whether it can provide an efficient means of detecting hazardous chemicals in industrial wastewaters.     

Evaluation of the acute, chronic and teratogenic effects of a mixture of eleven pharmaceuticals on the cnidarian, Hydra attenuata

Pharmaceuticals have recently emerged as novel pollutants of potential concern in the aquatic environment where they are commonly introduced as complex mixtures via municipal effluent. In the present experiment, the freshwater cnidarian Hydra attenuata was exposed to a mixture of 11 pharmaceuticals (ibuprofen, naproxen, gemfibrozil, bezafibrate, carbamazepine, sulfapyridine, oxytetracycline, novobiocin, trimethoprim, sulfamethoxazole and caffeine) up to 10 000 times (×) the concentration found in municipal effluent. Hydra regeneration and teratogenicity was measured, having an IC₅₀ of 781× and was found to be non teratogenic with an A/D value of ∼ 1. Toxicity was investigated using both lethal (based on morphology) and sub-lethal (based on morphology, feeding behaviour, hydranth number and attachment) endpoints. The pharmaceutical mixture incurred a significant decrease in morphology at 0.1, 10 and 100× but a significant increase at 1000×. All parameters were significantly reduced at 10 000×. An EC₅₀ of 425× and 65× based on morphology and feeding respectively and a toxicity threshold (TT) of 3.2× were calculated. When compared to the toxicity of each pharmaceutical exposed individually as previously reported [Quinn B, Gagné F, Blaise C. An investigation into the acute and chronic toxicity of eleven pharmaceuticals found in wastewater effluent on the cnidarian, H. attenuata. Sci Total Environ 2008a; 389: 306-314], the compounds in the mixture were present at concentrations 2 to 3 orders of magnitude lower for the equivalent toxicity (EC₅₀ and TT). These results indicate that pharmaceuticals act additively in a mixture, having sub-lethal effects at environmentally relevant (µg/L-ng/L) concentrations and that their combined concentrations could potentially prove significantly ecotoxic to Hydra and possibly to other aquatic taxa.