1、Designation: E 1197 87 (Reapproved 2004)Standard Guide forConducting a Terrestrial Soil-Core Microcosm Test1This standard is issued under the fixed designation E 1197; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t 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 defines the requirements and procedures forusing soil-core microcosms to test the environmental fate,ecologic
3、al effects, and environmental transport of chemicalsthat may enter terrestrial ecosystems. The approach and thematerials suggested for use in the microcosm test are alsodescribed.1.2 This guide details a procedure designed to supplysite-specific or possibly regional information on the probablechemic
4、al fate and ecological effects in a soil system resultingfrom the release or spillage of chemicals into the environmentin either liquid or solid form.1.3 Experience has shown that microcosms are most helpfulin the assessment process after preliminary knowledge aboutthe chemical properties and biolog
5、ical activity have beenobtained. Data generated from the test can then be used tocompare the potential terrestrial environmental hazards of achemical.1.4 This standard does not purport to address all of thesafety problems, if any, associated with its use. It is theresponsibility of the user of this
6、standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 422 Test Method for Particle-Size Analysis of SoilsD 511 Test Methods for Calcium and Magnesium in WaterD 515 Test Metho
7、ds for Phosphorus in Water3D 1426 Test Methods for Ammonia Nitrogen in WaterD 2167 Test Method for Density and Unit Weight of Soil inPlace by the Rubber Balloon MethodD 2216 Test Method for Laboratory Determination of Water(Moisture) Content of Soil, Rock, and Soil-AggregateMixturesD 2488 Practice f
8、or Description and Identification of Soils(Visual-Manual Procedure)D 3867 Test Method for Nitrite-Nitrate in Water2.2 U.S. Environmental Protection Agency:Environmental Effects Test Guidelines, EPA 560/6-82-002,19824Chemical Fate Test Guideline, EPA 560/6-82-003, 198253. Terminology3.1 Definition:3.
9、1.1 soil-core terrestrial microcosman intact soil-corecontaining the natural assemblages of biota surrounded by theboundary material. The system includes all equipment, facili-ties, and instrumentation necessary to maintain, monitor, andcontrol the environment.3.2 Description of Terms Specific to th
10、is Standard:3.2.1 terrestrial microcosm or micro-ecosystem a physi-cal model of an interacting community of autotrophs, omni-vores, herbivores, carnivores and decomposers within an intactsoil profile. The forcing functions, for example, light intensityand duration, water quality and watering regime,
11、 temperature,and toxicant dose for the test system, are under the investiga-tors control. This test system is distinguished from test tubeand single-species toxicity tests by the presence of a naturalassemblage of organisms. This assemblage creates a higherorder of ecological complexity and, thus, p
12、rovides the capacityto evaluate chemical effects on component interactions andecological processes. Certain features of this test system,however, set limits on the types of questions that can beaddressed. Those limitations are related to scale and sampling,which in turn constrain both (a) the type o
13、f ecosystems andspecies assemblages on which one can gain information, and(b) the longevity of the test system.3.2.2 physical, chemical, and biological conditions of testsystemdetermined by the type of ecosystem from which thetest system was extracted and by either the natural vegetation1This guide
14、is under the jurisdiction of ASTM Committee E47 on BiologicalEffects and Environmental Fate and is the direct responsibility of SubcommitteeE 47.02 on Terrestrial Assessment and Toxicology.Current edition approved August 1, 2004. Published August 2004. Orginallyapproved in 1987. Last previous editio
15、n approved in 1998 as E119787(1998).2For referenced ASTM standards, 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.3Withdrawn.4Available fro
16、m the Office of Pesticides and Toxic Substances, Washington, DC.Also available as PB82 23992 from National Technical Information Service(NTIS), United States Department of Commerce, 5285 Port Royal Rd., Spring-field, VA 22161.5Available from Office of Pesticides and Toxic Substances, Washington, DC.
17、Also available as PB82 233008 from National Technical Information Service(NTIS), United States Department of Commerce, 5285 Port Royal Rd., Spring-field, VA 22161.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.in the ecosystem or th
18、e crops selected for planting. Vegetationand crop selection are constrained and determined by the size(width and depth) of the soil core extracted.3.2.3 boundariesthe boundaries of the test system aredetermined by the size of the soil-core and the space needed forvegetative growth.3.2.4 lightlight f
19、or the test system can be supplied byartificial means in either a growth chamber or a greenhouse, orit can be the natural photoperiod occurring in a greenhouse. Ifthe test is performed in a growth chamber, the daily photope-riod should be equal to or greater than the average monthlyincident radiatio
20、n (quantity and duration) for the month inwhich the test is being simulated. During extremely shortnatural photoperiods, which might not allow for flowering orseed-set, photoperiod should be artificially lengthened to in-duce those responses.3.2.5 waterwater for the test system should either bepurif
21、ied, untreated laboratory water or should be precollected,filtered rainwater from the site or region being evaluated.Chemical characterization of the water, either laboratory orrainwater, is required and must be performed using TestMethods D 511, D 515, D 1426, and D 3867.3.2.6 soilthe soil-core use
22、d for the microcosm test shouldbe an intact, undisturbed (nonhomogenized) core extractedfrom a soil type typical of the region or site of interest. Thecore should be of sufficient depth to allow a full growingseason for the natural vegetation or the crops selected, withoutcausing the plants to becom
23、e significantly rootbound. Distur-bances during extraction and preparation should be kept to aminimum. It should be noted that soil characteristics play animportant role in how the microcosm responds to a testsubstance. In addition, within-site soil heterogeneity alsoinfluences the microcosm respons
24、e and contributes to a loss ofsensitivity of the test. The approach used in this test system,however, is based on a comparison of responses among andbetween treatments rather than on the absolute values mea-sured.3.2.7 biotathe biota of the microcosm are characterizedby the organisms in the soil at
25、the time of extraction (1, 2)6andby the natural vegetation or crops introduced as the autotrophiccomponent. The biota may include all heterotrophic andcarnivorous invertebrates typically found in the soil and all soiland plant microbes.4. Significance and Use4.1 This guide provides a test procedure
26、for evaluating thepotential ecological impacts and environmental transport of achemical in an agricultural (tilled, low-till, or no-till) or naturalfield soil ecosystem that may be released or spilled into theenvironment. The suggested test procedures are designed tosupply site-specific information
27、for a chemical without havingto perform field testing. (See EPA 560/6-82-002 and EPA 560/6-82-003.)4.2 This guide is not specifically designed to address fate ofchemicals in soils of forested ecosystems. However, with somemodifications, it may be adapted for that purpose by theindividual investigato
28、r.4.3 Specifically, this guide is used to determine the effect ofa chemical on (1) growth and reproduction of either naturalgrassland vegetation or crops, and (2) nutrient uptake andcycling within the soil/plant system. Additionally, the soil-coremicrocosm will provide information on (1) potential f
29、orbioaccumulation (enrichment) of the chemical into plant tis-sues, and (2) the potential for and rate of transport of thechemical through soil to ground water.4.4 The results of this test should be used in conjunctionwith information on the chemical and biological activity of thetest substance to a
30、ssess the relative environmental hazard andthe potential for environmental movement once released.4.5 The test methods described in this guide are designedspecifically for liquid or solid materials. Significant modifica-tions of the exposure system would be necessary to accommo-date chemicals that a
31、re volatile or that may be released in agaseous or aerosolized form. For methods that could beadapted for use with volatile or gaseous test substances seeRefs (3, 4, 5, 6).4.6 Results of a multi-year soil-core microcosm test havebeen correlated with data derived from a series of multi-yearfield plot
32、 tests for a limited number of materials. Informationon the correlation between microcosm and field results can befound in Refs (7, 8, 9, 10).5. Chemical Characterization of Test Substance and Soil5.1 Information Required on Test Substance:5.1.1 Minimum information required to properly design andcon
33、duct an experiment on a test chemical includes the chemicalsource, composition, degree of purity, nature and quantity ofany impurities present, and certain physiochemical informationsuch as water solubility and vapor pressure at 25C (11, 12).Ideally, the structure of the test chemical should also be
34、 known,including functional groups, nature and position of substitutinggroups, and degree of saturation. The octanol-water-partitioncoefficient, the dissociation constant, the degree of polarity, andthe pH of both pure and serial dilutions should also be known.Where mixtures are involved or where a
35、significant impurity(1 %) occurs, data must be available on as many componentsas practical. However, the octanol-water-partition coefficient(Kow) stands out as the key value. Soil sorption coefficient (Ks)or sorption constant (Koc) can be estimated from log Kowusingthe organic matter content. Water
36、solubility can be predictedwith some degree of accuracy from log Kowif this value is lessthan seven. In combination with other chemical characteristics,log Kowcan also be used to estimate Henrys Law Constant andthus provide a rough estimate of the potential volatility of thetest substance from soil
37、solutions.5.1.2 Several tests may be needed to supply information onenvironmental mobility and stability. Support information onphytotoxicity, the physicochemical nature of the chemical, itsmammalian toxicity, or its ecological effects (for example,species-specific LC50, invertebrate toxicity, biode
38、gradability)not only assist in proper design of the microcosm experiment,but also are useful in assessing the fate and effects of the6The boldface numbers in parentheses refer to a list of references at the end ofthis guide.E 1197 87 (2004)2chemical in a terrestrial microcosm. If the chemical is rad
39、io-actively labeled, the position and specific element to be labeledshould be specified.5.1.3 It is imperative to have an estimate of the testsubstance toxicity to mammals as a precaution for occupationalsafety. In addition, hydrolysis or photolysis rate constantsshould be known in order to determin
40、e necessary handlingprecautions. When a radiolabeled material is used, normallaboratory techniques for radiation safety provide an amplemargin of safety (13), except for chemicals in the “very highlytoxic” category (rat oral LD5025 mm Hg) are not suitable fortesting in the terrestrial soil-core micr
41、ocosm described in thisguide. According to Refs (6, 18), modification of the testsystem should be useful for handling gaseous or aerosolizedchemicals.5.2 Information Required on Soil:5.2.1 Soil sorption of an organic molecule depends onseveral properties of the chemical (molecular size, ionicspeciat
42、ion, acid-base properties, polarity, and nature of func-tional groups) and of the soil (for example, organic mattercontent, clay content, clay mineralogy and nature, pH, watercontent, bulk density, cation exchange capacity, and percentbase saturation). Highly sorbed chemicals may displace inor-ganic
43、 nutrient ions from exchange sites in the soil and also maybe effectively immobilized, depending on soil pH. Thus,chemicals attracted more strongly to soil surfaces than to watermay be very immobile in soil. In some cases, this may renderthe compound relatively resistant to biodegradation. In otherc
44、ases, however, immobilization of the compound on soilparticles may render it susceptible to extracellular enzymaticdegradation. Specific information on descriptive data requiredfor soil can be found in 6.2.2.6. Terrestrial Microcosm Extraction and Maintenance6.1 Microcosm and Cart Design:6.1.1 The 6
45、0-cm deep by 17-cm diameter terrestrial soil-core microcosm is designed to yield pertinent informationabout a chemical for either a natural grassland ecosystem or anagricultural ecosystem planted with a multiple-species crop(Fig. 1) (7, 8, 9, 19, 20). The agricultural microcosm is a 17-cmdiameter tu
46、be of plastic pipe7that is made of ultra-highmolecular weight, high-density, and nonplasticized polyethyl-ene and contains an intact soil core (40 cm) covered byhomogenized topsoil (20 cm). The natural grassland micro-cosm is an intact totally undisturbed 17-cm diameter by 60-cmdeep test system. The
47、 plastic pipe should be impermeable towater, light-weight, tough, rigid, and highly resistant to acids,bases, and biological degradation. Additionally, one should useplastic pipe that does not release plasticizers or other com-pounds that may interfere with test results. This tube sits on aBuchner f
48、unnel that is covered by a thin layer of glass wool.The funnel and tube are washed with 0.1 N HCl prior to useand are re-useable for future tests.6.1.2 Six to eight microcosms are typically contained in amoveable cart, which is packed with insulated beads, to reducedrastic changes in temperature pro
49、file (7, 19) (Fig. 2). Cartdimensions are determined by the environmental chamber sizeor the maneuverability required in the greenhouse. Carts aremounted on wheels so the cart can be moved within thegreenhouse in a manner defined by statistical requirements tomake exposure to light and temperature more uniform.6.2 Soil Core Extraction:6.2.1 Soil cores are extracted from either a natural grasslandecosystem or a typical agricultural soil in the region of interest.The intact system is extracted with a specially designed, steelextraction tube (7, 8, 9, 19, 20, 21) (Fig. 3)
