1、Designation: E 1768 95 (Reapproved 2008)Standard Guide forVentilatory Behavioral Toxicology Testing of FreshwaterFish1This standard is issued under the fixed designation E 1768; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers information on methods to measureand interpret ventilatory behavioral responses of freshwate
3、rfish to contaminants.1.2 Ventilatory responses are often some of the first prele-thal symptoms exhibited by animals to environmental stressors(1, 2, 3, 4, 5, 6, 7, 8, 9, 10).2Continued, abnormal ventilatorybehavior (that is, rapid or shallow breathing, erratic breathing)can indicate physiological d
4、amage that may be irreversible.Such damage could eventually result in decreased survival,growth, or reproduction of the organism, or all of these.1.3 Ventilatory responses of some fish species can bemeasured relatively easily and quickly, providing a useful toolfor biomonitoring studies of wastewate
5、rs, pure chemicals,surface water, and ground water.1.4 Appropriate studies of ventilatory responses can yielddefinitive endpoints such as no observable effect concentration(NOEC) or an EC50, often more rapidly than standard toxicitytest methods (11, 12).1.5 The mode of action of test substances and
6、the type ofchemical toxicant can be determined by examining ventilatorybehavioral responses in conjunction with other physiologicalresponses (8, 9, 10, 11, 12).1.6 Fish ventilatory behavior can be assessed in real-timeusing appropriate computer hardware and software (12, 13, 14,15, 16, 17, 18, 19).
7、Such systems have proved useful forlong-term, on-line monitoring of wastewater effluents, purechemicals, and surface waters (12, 15, 20, 21, 22, 23, 24, 25).These systems are usually technically complex and will not bediscussed in this guide.1.7 Given the technological constraints of electrical comp
8、o-nents, it is currently not feasible to monitor bioelectric signals,such as those elicited in ventilatory behavior, in saline (2 ppt)or high conductivity (3000 mhos/cm) water using theprocedures discussed in this guide. Therefore, this guide isrestricted to the testing of freshwater matrices.1.8 Th
9、is standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specific safetyp
10、recautions, see Section 6.1.9 This guide is arranged as follows:SectionNumberScope 1Referenced Documents 2Terminology 3Summary of Guide 4Significance and Use 5Safety Precautions 6Responses Measured 7Test System 8Test Procedure 9Data Collection and Analysis 10Interferences 11Documentation 12Reference
11、s 132. Referenced Documents2.1 ASTM Standards:3E 729 Guide for Conducting Acute Toxicity Tests on TestMaterials with Fishes, Macroinvertebrates, and Amphib-iansE 943 Terminology Relating to Biological Effects and En-vironmental FateE 1192 Guide for Conducting Acute Toxicity Tests onAqueous Ambient S
12、amples and Effluents with Fishes,Macroinvertebrates, and AmphibiansE 1241 Guide for Conducting Early Life-Stage ToxicityTests with Fishes1This guide is under the jurisdiction of ASTM Committee E47 on BiologicalEffects and Environmental Fate and is the direct responsibility of SubcommitteeE47.01 on A
13、quatic Assessment and Toxicology.Current edition approved Feb. 1, 2008. Published March 2008. Originallyapproved in 1995. Last previous edition approved in 2003 as E 1768 95(2003)e1.2The boldface numbers given in parentheses refer to a list of references at theend of the text.3For referenced ASTM st
14、andards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken
15、, PA 19428-2959, United States.E 1604 Guide for Behavioral Testing in Aquatic Toxicology3. Terminology3.1 The words “must,” “ should,” “may,” “can,” and“might” have very specific meanings. “Must” is used to expressan absolute requirement, that is, to state that the test ought tobe designed to satisf
16、y the specified condition, unless thepurpose of the test requires a different design. “Must” is onlyused in connection with the factors that directly relate to theacceptability of the test. “Should” is used to state that thespecified condition is recommended and ought to be met ifpossible. Although
17、a violation of one “should” is rarely aserious matter, violation of several will often render the resultsquestionable. Terms such as “is desirable,” “is often desir-able,” and “might be desirable” are used in connection withless important factors. “May” is used to mean “is (are) allowedto,” “can” is
18、 used to mean“ is (are) able to,” and “might”isused to mean “could possibly.” Thus the classic distinctionbetween “may” and “can” is preserved, and “might” is neverused as a synonym for either “may”or“can.”3.2 Definitions of Terms Specific to This Standard:3.2.1 coughgill purge in fish; when a fish
19、reverses orgreatly increases the flow of water over the gills and back outto the ambient water. Such activity is used to cleanse the gillsby removing particles or other material on the gill plate(s).3.2.2 electrodedevice (metallic or chemical based) thatreceives bioelectric signals from the organism
20、.3.2.3 ventilationbreathing, respiratory process of organ-ism.3.2.4 waveformrepresentation of analog electrical signaldepicting breathing response of organism over time, usuallyrepresented on a strip chart recorder or computer monitor.4. Summary of Guide4.1 The potential toxicity of water or a pure
21、chemical inwater is assessed by measuring changes in fish ventilatorybehavior during exposure using a flow-through system. Sig-nificant effects are determined by comparing specific ventila-tory responses of fish under control conditions with responsesof those same fish during exposure conditions. A
22、set of controlfish may also be used in the test design in order to evaluatenon-toxic changes in ventilatory response over time, particu-larly when longer-term monitoring is desired.4.2 Ventilatory responses are observed by using non-invasive metallic or chemically-based electrodes, a signalamplifica
23、tion and filtration system, and strip chart recorder (orother recording device) to display the ventilatory waveform. Inshort-term tests (24h in length or in continuous real-time monitoring applications,ventilatory waveform data are aquisitioned, analyzed, andstored via a microcomputer equipped with
24、an analog to digitalprocessor, disk or magnetic tape storage, and appropriatesoftware. With the aid of a computer and analog to digitalboard, responses can be monitored and analyzed on a real-timebasis. The computer-analyzed response reduces potential sub-jective biases due to manual analysis of str
25、ip-chart recordings.5. Significance and Use5.1 Responses that reflect oxygen consumption or utiliza-tion have often been targeted as useful indicators of incipienttoxic conditions (26, 27, 28, 29, 30). In addition, sustainedacute fish ventilatory behavioral responses reflect a physiologi-cal change
26、in the organism and therefore might have ecologicalrelevance.5.2 For some time, the technological means have beenavailable to log and display ventilatory signals over time. As aresult, there are a considerable number of studies whichexamined ventilatory behavior of fish and other aquatic organ-isms.
27、 A large number of substances at lethal levels have beenshown to elicit ventilatory responses relatively quickly (13, 19,20, 31, 32, 33, 34). For many pollutants, a significant responsewas often generated in less than1hofexposure to concentra-tions approaching the 96 h LC50. Studies performed usings
28、ubacutely toxic samples of effluents or individual pollutants(concentrations well below the reported LC50 concentration),often documented responses within 1 to 10 h of exposure (11,18, 21, 30, 35, 36).5.3 Given the data obtained thus far, it appears that fishventilatory behavior may be a very sensit
29、ive and rapid indica-tor of acute toxicity if various aspects of this behavior (that is,rate and amplitude) are assessed and analyzed simultaneously.It appears that the more aspects of ventilatory behavior that areassessed, the more sensitive and rapid the system is (11, 12, 21,22).5.4 Although a va
30、riety of organisms have been examinedincluding crayfish (37), aquatic insect larvae (31), and bivalves(13), most research in aquatic ventilatory behavior has usedfreshwater fish species. This is largely because fish are gener-ally more ecologically “visible” in their importance in aquaticsystems and
31、 many species (particularly the salmonids andcentrarchids) have large opercular flaps that yield relativelyclear ventilatory signals for measurement and evaluation.Species eliciting relatively small bioelectric ventilatory signalsare more difficult to use given the electrode and amplificationsystems
32、 referenced in this guide.5.5 Changes in ventilatory behavior have been shown to bea reliable indicator of accidental toxic spills or “slugs” ofpollutants in wastewater and drinking water systems (15, 20,23, 24, 33).6. Safety Precautions6.1 Many substances may pose health risks to humans ifadequate
33、precautions are not taken. Information on toxicity tohumans, recommended handling procedures, and chemical andphysical properties of the test material should be studied and allpersonnel informed before an exposure is initiated.(WarningSpecial procedures might be necessary with radio-labeled test mat
34、erials and with test materials that are, or aresuspected of being carcinogenic.)6.2 Many materials can adversely affect humans if precau-tions are inadequate. Contact with test material, sediments, andwater should be minimized. Where appropriate, protectivegloves, laboratory coats, aprons, protectiv
35、e clothing, and safetyglasses should be worn and dip nets, sieves, or tubes should beused to remove test organisms. When handling potentiallyE 1768 95 (2008)2hazardous materials, proper handling procedures may includemanipulating test materials under a ventilated hood or in anenclosed glovebox, encl
36、osing and ventilating the exposurechambers, and use of respirators, aprons, safety glasses andgloves.7. Responses Measured7.1 Ventilatory parameters in fish that have been shown tobe affected by toxicity include ventilatory rate (opercularmovement over time), depth of ventilation (amplitude), cough-
37、ing or gill purge rate, and erratic episode frequency due tosudden movement of the organism. Most commonly, changesin ventilatory rate (Fv) have been used as a bioindicator of toxicconditions (11, 12, 13, 19, 20, 21, 30, 31, 33, 34, 35, 36).However, depth of ventilation and cough rate have beenrepor
38、ted to be more sensitive indicators of toxicity for somecompounds (11, 19, 38, 39, 40).7.2 Manually, changes in ventilatory rate are often deter-mined by changes in the number of peaks per unit area on astrip-chart recording. Depth of ventilation (tidal volume) orsignal amplitude, is measured from t
39、op to the bottom of thewaveform (see Fig. 1).7.3 Cough rate has been more difficult to determine becauseseveral different types of coughs may be evident, each with itsown characteristic wave form pattern (see Fig. 1 and (11, 39,40). Also, without the use of video techniques, (11, 41), theactual occu
40、rrence of a cough is not always clear. Researcherswho have investigated cough responses have interpreted mostabnormal peaks or pattern changes on a strip-chart recording asa cough. Work by Diamond et al. (11) however, indicated thatmany of these changes may in fact be due to general activity,and not
41、 coughing responses. Various aspects of monitoring fishcoughs have been reviewed by Drummond and Carlson (40).7.4 Erratic episode frequency or activity episode frequencyhas also proved to be a useful response in some studies (11, 12,21). These episodes are represented on a strip chart recordingas a
42、multi-peak, high frequency (and often high amplitude)cluster of signals which can be easily distinguished from thenormal ventilatory signal (Fig. 1).8. Test System8.1 Several techniques have been developed to monitor fishventilatory behavior. The simplest and most reliable methodmonitors the bioelec
43、tric potentials generated during ventilatorymovements by means of noninvasive electrodes (11, 12, 16, 20,21, 29) or silver/silver chloride (15). These electrodes gener-ally consist of stainless steel wire or screen and are attached tothe monitoring chamber such that the fish is not restrained orstre
44、ssed (see Fig. 2).8.2 The spatial orientation of the electrodes within themonitoring chamber affects the intensity with which theventilatory signal is received and recorded. Since reception ofthe bioelectric signal is dependent on there being a polarity orelectrical gradient between the electrodes,
45、electrodes areplaced opposite each other in the monitoring chamber toachieve maximum sensitivity. Several different electrode ar-rangements have been utilized including top and bottom of thechamber (see Fig. 2(a) and (12, 15, 21), front and back (29),and sides of the chamber (see Fig. 2(b) and (11,
46、14, 20). Eachof these arrangements may have advantages and disadvantagesin terms of signal reception and the ability to detect subtlechanges in amplitude, body movement, or cough rates. Infor-mation at this time suggests that a top and bottom electrodearrangement (see Fig. 2(a), will reduce ventilat
47、ory signalalteration due to changes in fish position relative to theelectrodes in comparison with a side electron orientation (12).Test chambers must be clean prior to testing as described inPractice E 729, and made of appropriate construction materialssuch as glass or plexiglass (see Guide E 1241 a
48、nd PracticeE 729).8.3 Test organisms and chambers must be isolated so as toreduce external stimuli such as experimenter movement, vibra-tion, and visual cues. This is generally achieved by placing asingle fish in each chamber and by placing opaque dividersbetween test chambers. The entire system (al
49、l test chambers)should be isolated within a light-proof box or continuous lightcompartment.8.4 The electrical signal (microvolts), generated by ventila-tory movements, that is received by the electrodes, must beconditioned prior to use. First, the electrical components of thesystem must be properly grounded to avoid erratic signalreception. Second, electrical noise, particularly that arisingfrom normal 60 cycle electrical current (such as from lights,strip chart recorder, and amplifier), must be eliminated so thatthe fish ventilatory signal is received with minimal interfer-
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