摘要:

AbstractThe determination of site‐specific water quality criteria generally involves the recalculation of national criteria using laboratory‐derived toxicity data or the conducting of bioassays using site water. Because of uncertainty of predictions of in‐stream biological responses to contamination, an alternative procedure using stream benthic surveys and water quality data was applied at the Appalachian Power Company Clinch River Plant on the Clinch River in southwestern Virginia. Benthic surveys of riffle transects at four stations located upstream and downstream of the plant showed no significant differences among sites, except just below the effluent discharge site. During low‐flow periods there were significant decreases at this site in the percentage of mayflies in the organisms collected.Effluent and ambient chemical data were examined statistically with respect to the biological data. Increased copper concentrations were significantly associated with decreases, from reference levels, in percent mayflies at the impacted area. A linear equation was derived relating decreased percent mayflies to increased copper concentrations. A no effect level based on the least detectable difference in percent mayflies produced a total recoverable copper criterion of 34.2 μg/L. Criteria or impact estimates derived from in‐stream data possess many advantages; they are a valuable tool for reducing uncertainty through integrated field‐laboratory

ISSN:0730-7268    

DOI:10.1002/etc.5620050501

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractSite‐specific acute and chronic toxicity tests with un‐ionized ammonia were conducted in Tittabawassee River water from Midland, Michigan. The results of these tests were used by the State of Michigan Department of Natural Resources (MDNR) to establish site‐specific acute and chronic un‐ionized ammonia water quality criteria for the portion of the river at Midland. The acute water‐quality criterion established by the state using walleye data from this study was 1.0 mg/L un‐ionized ammonia nitrogen. The chronic criterion established using fathead minnow embryo‐larval data was 0.095 mg/L un‐ionized ammonia nitrogen. The chronic criterion was used in determining the assimilative capacity for ammonia in this portion of the river. The MDNR allocated a portion of the assimilative capacity to each discharger and set effluent limitations based on the allocated capacities. Ammonia effluent limits have been set in the National Pollutant Discharge Elimination System (NPDES) permits of the Dow Chemical Company and the City of Midland. Ammonia effluent limits will be set in the NPDES permit of the Consumer

ISSN:0730-7268    

DOI:10.1002/etc.5620050502

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe toxicity of ammonia to the juvenile stages of the bluegill (Lepomis macrochirus) and the walleye (Stizostedion vitreum), and to the embryo, larval and juvenile stages of the fathead minnow (Pimephales promelas) was determined in support of the development of a site‐specific water quality standard for ammonia in the Tittabawassee River at Midland, Michigan. There was little difference among the acute toxicities of ammonia (expressed as un‐ionized ammonia nitrogen NH3‐N) to the three species tested, with 96‐h LC50 values of 1.04, 1.06 and 1.50 mg NH3‐N/L for the bluegill, walleye and fathead minnow, respectively. Evaluation of the chronic data showed no concentration‐related effects for hatching success and growth. However, there was a significant (α = 0.05) decrease in number of normal larvae at hatch and in larval survival at 0.26 mg NH3‐N/L and higher. The maximum acceptable toxicant concentration fell between 0.17 and 0.26 mg NH3‐N/L, or 0.21 mg NH3‐N/L when expressed as the geometric mean of these values. Both the acute and chronic values derived during this study are similar to those reported in the literature, indicating that, in this case, Tittabawassee River water quality did not influence the toxicity of ammonia to

ISSN:0730-7268    

DOI:10.1002/etc.5620050503

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe acute and chronic toxicity of ammonia (expressed as un‐ionized ammonia nitrogen, NH3‐N) toDaphnia magnawas determined in support of the development of site‐specific water quality standards for ammonia in the Tittabawassee River at Midland, Michigan. The 48‐h LC50 value (95% confidence interval) obtained was 2.94 (2.70 to 3.22) mg NH3‐N/L. The 21‐d chronic value, presented as the maximum acceptable toxicant concentration (MATC), was between 0.42 and 0.87 mg NH3‐N/L. Expressing the chronic value as the geometric mean of 0.42 and 0.87 resulted in an MATC of 0.60 mg NH3‐N/L. The toxicity values derived during this study were similar to those reported in the literat

ISSN:0730-7268    

DOI:10.1002/etc.5620050504

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractEnvironmental risk assessment of pesticides in aquatic environments requires predictions of their persistence and compartmentalization. A strategy for developing confidence in predictive fate models, such as the Exposure Analysis Modeling System (EXAMS) and the Simplified Lake and Stream Analysis model (SLSA), is to test the models using carefully chosen chemicals in semi‐controlled and field situations. For example, endothall, a relatively water‐soluble aquatic herbicide, essentially has a sole fate process, biotransformation. This dicarboxylic acid was used to test the predictive capabilities of EXAMS and SLSA and to identify sources of variance in those predictions. The models were parameterized using laboratory, experimental pool and field measurements. Persistence and compartmentalization of endothall in the water, sediments and aquatic plants (Eurasian watermilfoil—Myriophyllum spicatumL.) contained in experimental pools were measured using gas chromatography. Both EXAMS and SLSA predicted aqueous compartment half‐lives ranging from 7.3 to 7.8 d, whereas an aqueous half‐life of 4 d was observed in the experimental pools. Endothall was introduced to areas within Pat Mayse Lake, a 2,400‐ha reservoir in north central Texas, as part of an aquatic plant management program forM. spicatum.Concentrations of endothall were below detection limits (0.002 mg L−1water, 0.01 mg kg−1sediment) in 2 to 3 d and in 4 d in the water and sediment compartments, respectively. EXAMS and SLSA predicted half‐lives ranging from 3 to 6 d in the water column. Observed aqueous half‐lives ranged from 0.1 to 0.23 d. Horizontal dispersion and dilution contributed significantly to the dissipation of endothall at these sites. Predicted concentrations of endothall in sediment were similar to the measured concentrations. This study is one validation trial of EXAMS and SLSA in which the models were not c

ISSN:0730-7268    

DOI:10.1002/etc.5620050505

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractPairs of orangespotted sunfish were exposed to oil refinery wastewaters in acute, non‐lethal toxicity tests. Frequencies of agonistic behaviors (approaches, fin erections, tail beats, operculum spreads, chases, bites and avoidances) were determined initially after a 10‐d exposure to control water and then again after a 10‐d exposure to the wastewaters. Changes in frequency were compared with changes in frequency for pairs of fish exposed to control water for both 10‐d periods.Pairs of fish were observed for 60 min following each of the two 10‐d exposures. Frequencies during the initial 15 and 30 min of the period and during the entire 60‐min period were determined. For wastewater‐exposed fish, the frequency of each behavior generally decreased following the 10‐d exposure to wastewater. For fish exposed only to the control water, each behavior generally increased in frequency following the second 10‐d period. The change in frequency for wastewater‐exposed fish was significantly (p<0.05) different from that for control fish for approaches, fin erections, chases, bites and avoidances at one or more of the three lengths (15, 30 and 60

ISSN:0730-7268    

DOI:10.1002/etc.5620050506

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractAn aquatic, multicomponent microcosm simulating a northern prairie wetland was used to assess the potential effects of six extensively used agricultural pesticides on this important wildlife habitat. Using a nested experimental design, 16 4‐liter aquatic microcosms were treated with three concentrations of each of the pesticides carbofuran, fonofos, phorate, atrazine, treflan and trial‐late. The microcosm units were incubated for 30 d in an environmental chamber, with a 16‐h light:8‐h dark cycle, maintained at 20°C. Specific limnological, biological and toxicological parameters were monitored over time by observing the interactions of water, animals, sediment and plants with the pesticides. The laboratory protocol was designed as an initial, rapid, economical screening test to determine the effect, but not the fate, of chemical contaminants in terms of toxicity, impaired productivity and community biochemical functions.Static acute toxicity tests withDaphnia magnaandChironomus ripariussuggested that carbofuran, fonofos, phorate and triallate were very toxic to aquatic invertebrates. ForD. magnathe 48‐h EC50 values were 48, 15, 19 and 57 μg/L, respectively. Invertebrate viability tests indicated rapid changes in the toxicological persistence of these pesticides after microcosm interaction. Populations ofD. magnawere established in the 10 μg/L test concentration of carbofuran, phorate, triallate and fonofos at 1, 1, 14 and 28 d, respectively. Preexposure of the wetland sediments to either triallate or fonofos did not appear to change the relative toxicological persistence of each compound in the water column. Changes in pH, alkalinity, conductivity, dissolved oxygen, total nitrogen and total phosphorus were also observed with different pesticide treatments. Atrazine significantly reduced gross primary productivity and inhibited algal and macrophytic growth. In general, there was no evidence of significant inhibition of microbial functions in the water or hydrosoil of the treated microcosms. The respiratory electron transfer system, phosphatase activity, oxygen consumption and mineralization of dissolved organic carbon were not significantly impacted by any of these pesticides in hydrosoils. However, the impact of atrazine, fonofos and triallate on invertebrates and plants in the microcosm—both key elements in wetland productivity—would suggest that caution be used in application of these pesticides in or near

ISSN:0730-7268    

DOI:10.1002/etc.5620050507

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractBioassays were used in a three‐phase research project to (a) assess the comparative sensitivity of test organisms to known classes of chemicals, (b) determine if the chemical components in field soil and water samples of unknown chemical composition could be inferred from laboratory studies using pure chemicals and (c) investigate kriging (a relatively new statistical “mapping” technique) and bioassays as methods to define the areal extent of chemical contamination.The algal assay generally was most sensitive to samples of pure chemicals, soil elutriates and water from eight sites with known chemical contamination. Bioassays of nine samples of unknown chemical composition from the Rocky Mountain Arsenal site showed that a lettuce seed soil contact phytoassay was most sensitive. Preliminary evidence suggests that bioassays might be a useful tool in broadly identifying classes of toxic components of contaminated soil. Nearly pure formulations of insecticides and herbicides were less toxic than were their counterpart commercial formulations. This finding indicates that chemical analysis alone may fail to correctly rate the severity of possible environmental toxicity. Finally, we demonstrate that the lettuce seed phytoassay and kriging techniques can be used to map contamination in a portion of the Rocky Mountain Arsenal site and aid in cleanup deci

ISSN:0730-7268    

DOI:10.1002/etc.5620050508

出版商:Wiley Periodicals, Inc.    

年代:1986

数据来源: WILEY