Home About us Contact
|
Home About us Contact | ||
|
|
||
Water Quality Criteria (water + quality_criterion)
Selected AbstractsCopper Concentrations in Channel Catfish Ictalurus punctatus Ponds Treated with Copper SulfateJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2004Aaron A. McNevin Copper sulfate (CuSO45H2O) is used to reduce the abundance of blue-green algae and combat off-flavor in channel catfish culture. Copper sulfate usually is applied at a concentration of one-one hundredth of the total alkalinity. A study was performed at the Auburn University Fisheries Research Unit to determine the duration of elevated copper (Cu) concentration following copper sulfate applications. Two alkalinity treatments, 20-40 mg/L and 110-130 mg/L (as CaCO3), were examined. Copper sulfate was applied biweekly for 14 wk at 03 mg/L for the low alkalinity treatment and 1.2 mg/L for the high alkalinity treatment. Total copper concentrations in pond waters declined to the background level by 48-h post treatment. In addition, total copper concentrations were determined in waters of 38 catfish production ponds located in west central Alabama. The mean and standard deviation were 0.0092 ± 0.0087 mg Cu/L. Copper quickly precipitates from the water or is absorbed by sediments following copper sulfate treatment. Although concentrations of copper in pond waters increase immediately following copper sulfate treatment, they rapidly decrease and seldom exceed the United States Environmental Protection Agency's National Recommended Water Quality Criteria for Priority Toxic Pollutants of 0.013-mg Cu/L. Findings of this study suggest that copper sulfate treatment will not contaminate effluent from catfish ponds because of the short time that applied copper remains in the water column. Furthermore, the most frequent applications of copper sulfate occur in late summer months when rainfall is minimal and pond overflow is rare. [source] Risk assessment of herbicide mixtures in a large European lakeENVIRONMENTAL TOXICOLOGY, Issue 2 2008Nathalie Chèvre Abstract Lake Geneva is one of the largest European lakes with a surface area of 580 km2. Its catchment area covers 7400 km2, of which ,20% is arable land. Monitoring campaigns have been carried out in 2004 and 2005 to determine the contamination of the lake by pesticides. The results highlight the widespread presence of herbicides in water, the measured concentrations for most substances remaining constant in 2004 and 2005. However, for some individual herbicides the concentrations increased drastically (e.g., the herbicide foramsulfuron). We assessed the environmental risk of the herbicides detected in the lake using water quality criteria recently determined for the Swiss environmental protection agency. Furthermore, we assessed the risk of herbicide mixtures, grouped based upon their mode of action. Generally, the risk estimated for all single substances is low, except for some sulfonylurea compounds. For these substances, the measured concentrations are higher than the predicted no-effect concentration. Impact on the flora of the lake can therefore not be excluded. When mixtures of pesticides with similar mode of action are taken into account, the risk remains lower than the mixture water quality criteria for all groups, but can reach as high as one third of this quality criteria. A further step would therefore be to assess the risk of the total pesticide mixture, including similar and dissimilar modes of action. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. [source] Relationship between biotic ligand model-based water quality criteria and avoidance and olfactory responses to copper by fishENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2010Joseph S. Meyer Abstract The U.S. Environmental Protection Agency's (U.S. EPA) water quality criteria for Cu were tested to determine whether they protect fish against neurophysiological impairment. From published studies with rainbow trout (Oncorhynchus mykiss), Chinook salmon (Oncorhynchus tshawytscha), coho salmon (Oncorhynchus kisutch), and fathead minnows (Pimephales promelas), 20% inhibition concentrations (IC20s) were calculated for avoidance of Cu-containing water and for impairment of electroencephalogram (EEG) and electro-olfactogram (EOG) responses to natural odorants in Cu-containing water. Additionally, a Cu-olfactory biotic ligand model (BLM) that fits the coho salmon EOG data was parameterized by changing the sensitivity parameter in the ionoregulatory-based BLM. The IC20s calculated from reported Cu avoidance, EEG, and EOG data and IC20s predicted by the olfactory BLM were compared with acute and chronic Cu criteria calculated using U.S. EPA's BLM 2007 or hardness-adjustment equations. The BLM-based chronic criteria were protective in all 16 exposure water,species combinations used in avoidance and olfaction experiments. Additionally, the BLM-based acute criteria were protective in all 11 exposure water,species combinations in which comparisons could be made with olfactory BLM-predicted IC20s but not in two of the 16 exposure water,species combinations in which comparisons could be made with the reported IC20s (which were ,8% lower than but did not differ significantly from the BLM-based acute criteria; p,>,0.05). In effect, the olfactory BLM factored out the relatively high variability in the reported IC20s. It is concluded that the U.S. EPA's BLM-based water quality criteria for Cu protect against these types of neurophysiological impairment in the six species,endpoint combinations analyzed in this paper. However, the U.S. EPA's hardness-based criteria for Cu sometimes were considerably underprotective and sometimes were much less protective than the BLM-based criteria. Environ. Toxicol. Chem. 2010;29:2096,2103. © 2010 SETAC [source] Chronic toxicity of lead to three freshwater invertebrates,Brachionus calyciflorus, Chironomus tentans, and Lymnaea stagnalisENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2006Martin Grosell Abstract Chronic lead (Pb) toxicity tests with Brachionus calyciflorus, Chironomus tentans, and Lymnaea stagnalis were performed in artificial freshwaters. The no-observable-effect concentration (NOEC), lowest-observable-effect concentration (LOEC), and calculated 20% effect concentration (EC20) for the rotifer B. calyciflorus were 194, 284, and 125 ,g dissolved Pb/L, respectively. The midge C. tentans was less sensitive, with NOEC and LOEC of 109 and 497 ,g dissolved Pb/L, respectively, and the snail L. stagnalis exhibited extreme sensitivity, evident by NOEC, LOEC, and EC20 of 12, 16, and <4 ,g dissolved Pb/L, respectively. Our findings are presented in the context of other reports on chronic Pb toxicity in freshwater organisms. The L. stagnalis results are in agreement with a previous report on pulmonate snails and should be viewed in the context of current U.S. Environmental Protection Agency (U.S. EPA) hardness adjusted water quality criteria of 8 ,g Pb/L. The present findings and earlier reports indicate that freshwater pulmonate snails may not be protected by current regulatory standards. Measurements of whole-snail Na+ and Ca2+ concentrations following chronic Pb exposure revealed that Na+ homeostasis is disturbed by Pb exposure in juvenile snails in a complicated pattern, suggesting two physiological modes of action depending on the Pb exposure concentration. Substantially reduced growth in the snails that exhibit very high Ca2+ requirements may be related to reduced Ca2+ uptake and thereby reduced shell formation. [source] Use of laboratory toxicity tests with bivalve and echinoderm embryos to evaluate the bioavailability of copper in San Diego Bay, California, USAENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2005Gunther Rosen Abstract Copper concentrations in parts of San Diego Bay (CA, USA) exceed ambient water quality criteria (WQC; currently 3.1 ,g/L dissolved, U.S. Environmental Protection Agency [U.S. EPA]). In order to better understand the bioavailability of copper to water-column organisms in the bay, toxicity tests were performed with copper added to surface water collected from various sites in the estuary over a three-year period. The species and endpoints used, bivalve and echinoderm embryo-larval development, are among the most sensitive in the U.S. EPA's national toxicity dataset, which is used to derive WQC. No toxicity was observed in ambient bay water samples, as indicated by high proportions of normally developed larvae in control treatments, averaging 93 ± 5% across all sites and all sampling events. Median effects concentrations (EC50), obtained by copper spiking of ambient water samples, ranged from 1.7 to 3.4 times lower at sites located near the mouth compared to sites near the back of the bay. These data indicate a gradient in complexation capacity increasing from the mouth to the back of the bay, which is consistent with similar trends in dissolved organic carbon and total suspended solids. For the bay as a whole, estimates for total recoverable and dissolved water-effect ratios (WER) ranged from 2.07 to 2.27 and 1.54 to 1.67, respectively. Water-effect ratios of this magnitude suggest that adoption of a somewhat higher site-specific WQC for San Diego Bay still would achieve the level of protection that is intended by the WQC guidelines. [source] Acute and chronic toxicity of nickel to marine organisms: Implications for water quality criteriaENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2002John W. Hunt Abstract Acute and chronic toxicity tests were conducted to determine the effects of nickel on three U.S. west coast marine species: a fish (the topsmelt, Atherinops affinis), a mollusk (the red abalone, Haliotis rufescens), and a crustacean (the mysid, Mysidopsis intii). The 96-h median lethal concentration (LC50) for topsmelt was 26,560 mg/L, and the chronic value for the most sensitive endpoint in a 40-d exposure was 4,270 mg/L. The median effective concentration (EC50) for 48-h abalone larval development was 145.5 ,g/L, and the chronic value for juvenile growth in a 22-d exposure through larval metamorphosis was 26.43 mg/L. The mysid 96-h LC50 was 148.6 ,g/L, and the chronic value for the most sensitive endpoint in a 28-d, whole life-cycle exposure was 22.09 ,g/L. The abalone and mysid acute values were lower than other values available in the literature. Acute-tochronic ratios for nickel toxicity to the three species were 6.220, 5.505, and 6.727, respectively, which were similar to the only other available saltwater value of 5.478 (for Americamysis [Mysidopsis] bahia) and significantly lower than the existing values of 35.58 and 29.86 for freshwater organisms. Incorporation of data from the present study into calculations for water quality criteria would lower the criterion maximum concentration and raise the criterion continuous concentration for nickel. [source] Partitioning of copper at concentrations below the marine water quality criteria,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2001Anthony J. Paulson Abstract Partitioning of Cu between the aqueous and particulate phases and among their components was examined in six ambient Puget Sound, Washington State, USA, samples (6,10 nM Cu). Most of the particulate Cu (4,12% of the total Cu) was associated with particulate organic matter, and resulted in distribution coefficients (Kd) ranging between 104,55 and 105,1. For the dissolved phase, the portion of Cu extracted by C18 -packed cartridges averaged 44% (+ 11%). Radioactive 64Cu was added to these samples to total stable Cu concentrations (17,33 nM). After 24 h of equilibration, the portion of 64Cu associated with the particulate matter in five of the six samples (Kd between 1047 and 1053) was an average of 70% higher than that of natural Cu in the ambient samples. In contrast, only 19 ± 7% of the 64Cu was extracted by C18 -packed cartridges. The partitioning of natural Cu and 64Cu onto particles was not significantly different when the equilibria were based on dissolved Cu passing through the C18 cartridges. Further research is warranted on utilizing the hydrophilic component of the dissolved phase as a parameter on which water quality criteria are based. [source] Technical basis for narcotic chemicals and polycyclic aromatic hydrocarbon criteria.ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 8 2000Abstract A method is presented for developing water quality criteria (WQC) for type I narcotic chemicals in general and PAHs in particular. The criteria can be applied to any individual or mixture of narcotic chemicals using only the chemical's octanol-water partition coefficient KOW. It is derived from a database of LC50s comprising 156 chemicals and 33 species, including fish, amphibians, arthropods, mollusks, polychaetes, coelenterates, and protozoans. A target lipid model is proposed that accounts for variations in toxicity due to differing species sensitivities and chemical differences. The model is based on the idea that a target lipid is the site of action in the organism. Further, it is assumed that target lipid has the same lipid-octanol linear free energy relationship for all species. This implies that the slope of the log(LC50),log(KOW) relationship is the same for all species. However, individual species may have varying target lipid body burdens that cause toxicity. The target lipid LC50 body burdens derived from concentration data in the water only are compared to measured total lipid LC50 body burdens for five species. They are essentially equal, indicating that the target lipid concentration is equal to the total extracted lipid concentration. The precise relationship between partitioning in target lipid and octanol is established. The species-specific body burdens are used to determine the WQC final acute value, i.e., the 95-percentile level of protection. An acute-to-chronic ratio is used to compute the body burden corresponding to the WQC final chronic value, which is the procedure used to derive the U.S. Environmental Protection Agency water quality criteria. The criteria are expressed either as dissolved concentrations in the water column or as tissue concentrations. [source] Effects of hydrogeomorphic region, catchment storage and mature forest on baseflow and snowmelt stream water quality in second-order Lake Superior Basin tributariesFRESHWATER BIOLOGY, Issue 5 2003Naomi E. Detenbeck SUMMARY 1. In this study we predict stream sensitivity to non-point source pollution based on the non-linear responses of hydrological regimes and associated loadings of non-point source pollutants to catchment properties. We assessed two hydrologically based thresholds of impairment, one for catchment storage (5,10%) and one for mature forest (<50% versus >60% of catchment in mature forest cover) across two different hydrogeomorphic regions within the Northern Lakes and Forest (NLF) ecoregion: the North Shore [predominantly within the North Shore Highlands Ecological Unit] and the South Shore (predominantly within the Lake Superior Clay Plain Ecological Unit). Water quality samples were collected and analysed during peak snowmelt and baseflow conditions from 24 second-order streams grouped as follows: three in each region × catchment storage × mature forest class. 2. Water quality was affected by a combination of regional influences, catchment storage and mature forest. Regional differences were significant for suspended solids, phosphorus, nitrogen: phosphorus ratios, dissolved organic carbon (DOC) and alkalinity. Catchment storage was significantly correlated with dissolved silica during the early to mid-growing season, and with DOC, specific conductance and alkalinity during all seasons. Total nitrogen and dissolved nitrogen were consistently less in low mature forest than in high mature forest catchments. Catchment storage interacted with the influence of mature forest for only two metrics: colour and the soluble inorganic nitrogen : phosphorus ratio. 3. Significant interaction terms (region by mature forest or region by storage) suggest differences in regional sensitivity for conductance, alkalinity, total organic carbon, and colour, as well as possible shifts in thresholds of impact across region or mature forest class. 4. Use of the NLF Ecoregion alone as a basis for setting regional water quality criteria would lead to the misinterpretation of reference condition and assessment of condition. There were pronounced differences in background water quality between the North and South Shore streams, particularly for parameters related to differences in soil parent material and glacial history. A stratified random sampling design for baseflow and snowmelt stream water quality based on both hydrogeomorphic region and catchment attributes improves assessments of both reference condition and differences in regional sensitivity. [source] Covalently linked immunomagnetic separation/adenosine triphosphate technique (Cov-IMS/ATP) enables rapid, in-field detection and quantification of Escherichia coli and Enterococcus spp. in freshwater and marine environmentsJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2010C.M. Lee Abstract Aims:, Developing a rapid method for detection of faecal pollution is among the critical goals set forth by the Environmental Protection Agency in its revision of water quality criteria. The purpose of this study is to devise and test covalently linked antibody,bead complexes for faecal indicator bacteria (FIB), specifically Escherichia coli or Enterococcus spp., in measuring water quality in freshwater and marine systems. Methods and Results:, Covalently linked complexes were 58,89% more robust than antibody,bead complexes used in previous studies. Freshwater and marine water samples analysed using covalently linked immunomagnetic separation/adenosine triphosphate quantification technique (Cov-IMS/ATP) and culture-based methods yielded good correlations for E. coli (R = 0·87) and Enterococcus spp. (R = 0·94), with method detection limits below EPA recreational water quality health standards for single standard exceedances (E. coli, 38 cells per 100 ml; Enterococcus spp. , 25 cells per 100 ml). Cov-IMS/ATP correctly classified 87% of E. coli and 94% of Enterococcus spp. samples based on these water quality standards. Cov-IMS/ATP was also used as a field method to rapidly distinguish differential loading of E. coli between two stream channels to their confluence. Conclusions:, Cov-IMS/ATP is a robust, in-field detection method for determining water quality of both fresh and marine water systems as well as differential loading of FIB from two converging channels. Significance and Impact of the Study:, To our knowledge, this is the first work to present a viable rapid, in-field assay for measuring FIB concentrations in marine water environments. Cov-IMS/ATP is a potential alternative detection method, particularly in areas with limited laboratory support and resources, because of its increased economy and portability. [source] INPUTS OF COPPER-BASED CROP PROTECTANTS TO COASTAL CREEKS FROM PASTICULTURE RUNOFF,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 2 2001Andrea M. Dietrich ABSTRACT: Inputs of copper-based crop protectants from tomato fields grown under plastic mulch agriculture (plasticulture) to an estuarine creek were investigated. Copper was measured in runoff from diverse land-uses including conventional agriculture, plasticulture, residences, and natural areas. Water column and sediment copper concentrations were measured in plasticulture and control (nonagriculture) watersheds. Copper concentrations in plasticulture-impacted creeks exceeded background levels episodically. High concentrations occurred during or immediately after runoff-producing rains. Concentrations of 263 ,g/L total copper and 126 ,g/L dissolved copper were measured in a tidal creek affected by plasticulture; concentrations exceeded the shellfish LC50 values and the water quality criteria of 2.9 ,g/L dissolved copper. Control watersheds indicated background water column levels of , 4 ,g/L dissolved copper with similar copper levels during periods with and without rain. The copper concentrations in tomato plasticulture field runoff itself contained up to 238 ,g/L dissolved copper. Copper concentrations in runoff from other land-uses were less than 5 ,g/L dissolved copper. Creek sediment samples adjacent to a plasticulture field contained significantly higher copper concentrations than sediments taken from nonplasticulture watersheds. [source] | |||||||||||||